Results in Journal Hacettepe Journal of Biology and Chemistry: 349
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Published: 3 October 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.962119
A heterogenous catalyst in the form of Au nanoparticles (Au NPs) immobilized porous manganese oxide (Mn5O8) microspheres was synthesized. The sol-gel templating method was used for the synthesis of Mn5O8 microspheres. The heterogenous catalyst showed good performance when compared with similar catalysts in the oxidation of benzyl alcohol. The heterogenous catalyst ([email protected]) obtained by the immobilization of Au NPs on Mn5O8 microspheres performed 99.4% of benzyl alcohol conversion and 100 % of benzaldehyde formation yield. Also the heterogenous catalyst showed a good stability and agglomeration resistance in the reusabilty experiments. [email protected] microspheres could be reused up to 5 times without remarkable loss in the catalytic activity. Altın nanopartiküllerle (Au NP'ler) dekore edilmiş gözenekli manganez oksit (Mn5O8) mikroküreleri formunda heterojen bir katalizör sentezlenmiştir. Mn5O8 mikrokürelerinin sentezi için sol-jel kalıplama yöntemi kullanılmıştır. Sentezlenen heterojen katalizör, benzil alkol oksidasyonunda benzer katalizörlerle karşılaştırıldığında iyi performans göstermiştir. Au NP'lerin Mn5O8 mikroküreleri üzerinde immobilizasyonu ile elde edilen heterojen katalizör ([email protected]) ile %99.4 benzil alkol dönüşümü ve %100 benzaldehit oluşum verimi elde edilmiştir. Ayrıca heterojen katalizör, tekar kullanılabilirlik deneylerinde iyi bir stabilite ve aglomerasyona karşı direnç göstermiştir. [email protected] mikroküreleri, katalitik aktivitede kayda değer bir kayıp olmaksızın 5 kata kadar yeniden kullanılabilmiştir.
Published: 3 October 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.892592
Increased activity of aldose reductase (AR) and sorbitol dehydrogenase (SDH) are the major causes of diabetic complications. Thus, inhibition of these two enzymes is vital in preventing diabetic complications. As the synthesis of new and effective AR and SDH enzyme inhibitors is quite difficult, we have investigated the inhibition effects of antibiotics, which are already widely used in medicine, on AR and SDH enzymes. AR and SDH enzymes were purified from bovine kidney, in vitro effects of antibiotics on enzymes were determined, and molecular docking simulations were carried out to understand inhibition mechanisms. The antibiotics ampicillin and amikacin inhibited both AR and SDH enzymes at very low concentrations. The best inhibitors for AR were found to be ceftriaxone, tylosin, and metronidazole with IC50 values of 28.75 µM, 49.28 µM and 58.42 µM, respectively. The best inhibitors for SDH were seen to be amikacin, ampicillin, and ceftazidime with IC50 values of 2.4 mM, 2.62 mM, and 3.76 mM, respectively. The results of inhibition and docking studies showed that antibiotics are highly effective on these enzymes. The results obtained can be used as a reference for synthesizing better inhibitors in future studies. Öz Aldoz redüktaz (AR) ve sorbitol dehidrogenazın (SDH) artan aktivitesi, diyabetik komplikasyonların başlıca nedenleridir. Bu nedenle, bu iki enzimin inhibisyonu, diyabetik komplikasyonların önlenmesinde hayati önem taşımaktadır. Çalışmamızda, yeni ve etkili AR ve SDH enzim inhibitörlerinin sentezi oldukça zor olduğundan, halihazırda tıpta yaygın olarak kullanılan antibiyotiklerin AR ve SDH enzimleri üzerindeki inhibisyon etkileri araştırılmıştır. AR ve SDH enzimleri sığır böbreğinden saflaştırılmış, antibiyotiklerin enzimler üzerindeki in vitro etkileri belirlenmiş ve inhibisyon mekanizmalarının aydınlatılması amacıyla moleküler docking simülasyonları gerçekleştirilmiştir. Ampisilin ve amikasin antibiyotikleri hem AR hem de SDH enzimlerini çok düşük konsantrasyonlarda inhibe etmiştir. AR için en iyi inhibitörlerin sırasıyla 28.75 µM, 49.28 µM ve 58.42 µM IC50 değerleri ile seftriakson, tylosin ve metronidazol antibiyotikleri olduğu bulunmuştur. En iyi SDH inhibitörlerinin sırasıyla 2,4 mM, 2,62 mM ve 3,76 mM IC50 değerleri ile amikasin, ampisilin ve seftazidim olduğu görülmüştür. İnhibisyon ve docking çalışmalarının sonuçları, antibiyotiklerin bu enzimler üzerinde oldukça etkili olduğunu göstermiştir. Elde edilen sonuçlar, gelecekteki çalışmalarda daha iyi inhibitörlerin sentezlenmesi için referans olarak kullanılabileceği düşünülmektedir.
Published: 3 October 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.925338
The present study identifies the hot spot of Yenice and aims to determine the tree diversity in the Fagus-Abies, Fagus and Quercus-Fagus forests, to define the microbial community in these forests by the Biolog-Ecoplate method and to reveal the physiological profile differences at the community level between forests. Accordingly, soil samples were taken from these predefined forests and the microbial community in different forests communities was analyzed using the Biolog EcoPlate method. In addition, cover-proportion values of the tree species were determined according to Braun-Blanquet method. As a results, the diversity in microbial communities has been determined as Fagus-Abies (3.0033 ± 0.006), Fagus (1.2267 ± 0.006) and Quercus-Fagus (1.1267 ± 0.012), from highest to lowest, respectively. On the other hand, the fact that the diversity of carbon sources in the Fagus forest was quite high and the use of phosphate carbon is seen only in this type of forest is quite significant. In the present study, the Biolog Ecoplate method was applied for the first time to determine the microbial community among forest communities. The results obtained from the present study clearly show the practicability and effectiveness of this method in forest communities. Meanwhile, determination of the microbial community will contribute to the development of new strategies for establishing ecosystem protection practices.
Published: 6 August 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.932240
Published: 5 August 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.937728
Published: 5 August 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.961220
Published: 25 June 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.892060
Colon cancer is the third most commonly diagnosed cancer in men worldwide. Colon cancer grows slowly and metastasis has already occurred after diagnosis. Therefore, new targets are needed in the colon cancer treatment and diagnosis. Transmembrane proteins (TMEM) play a critical role and presents different expression profile in variety of tumor cells. TMEM106C is a TMEM family protein, but its role on colon cancer development is unknown. In this study, we aimed to investigate TMEM106C gene in metastatic colon cancer cells. TMEM106C gene expression level was tested by western blot, qRT-PCR and immunofluorescence methods. In order to test the effect of TMEM106C in colon cancer cells, this gene has been knockdown with shRNA technology. In addition, cell invasion, migration and adhesion assays were performed to clarify whether TMEM106C knockdown has effect on colon cancer metastatic characters. Ford the first time, in this study, we showed TMEM106C is overexpressed in colon carcinoma cells. Moreover, we demonstrated that cell migration, invasion and adhesion capabilities are reduced in TMEM106C silenced cells. Furthermore, we observed that metastatic cell morphology was changed upon to TMEM106C knockdown. In conclusion, we showed that TMEM106C gene is important for colon carcinoma cells.
Published: 25 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.918700
Son yıllarda, dünya çapında gıda alerjisi en önemli sorunlardan biridir. Ovalbumin yumurta akında bulunan ana alerjanlardan biridir. Bu çalışmada, ovalbumin baskılanmamış ve baskılanmış poli (hidroksietil metakrilat-metakrilik asit) poli(HEMA-MAA) kriyojeller moleküler baskılama yöntemi kullanılarak sentezlenmiştir. Ovalbumin baskılanmış kriyojellerin karakterizasyonundan sonra, akış hızı, pH etkisi, başlangıçtaki ovalbumin konsantrasyonu ve sıcaklık parametrelerinin etkisi incelenmiştir. Ovalbumin baskılanmış ve baskılanmamış kriyojellerin ovalbumine karşı seçiciliğinin belirlenmesi, yarışmacı moleküller olarak lizozim ve transferrin kullanılarak gerçekleştirilmiştir. Ayrıca ovalbumin baskılanmış kriyojellerin yeniden kullanılabilirlik deneyleri gerçekleştirilmiştir. Ovalbuminin saflığı, sodyum-dodesil sülfat poliakrilamid jel elektroforezi kullanılarak yumurta akından belirlenmiştir.
Published: 24 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.923371
Both Gram negative and positive bacterial strains are known as the most frequently responsible causative agents for wound infections. These infections can resulted in morbidity and mortality due to the severity. Antimicrobial agents have often been preferred to treat these infections. In this respect, Cefuroxime (CXM) belongs to the second-generation cephalosporins could be suggested against wound infections. In recent years, designing of drug delivery systems have received interest and cryogels are promising tools for creating these systems. Their elastic nature, high macroporosity, absorption and releasing ability make these materials unique for drug delivery. Besides, imprinting approach could be integrated into cryogelation and resultant matrix has an ability to recognize target antimicrobial agent having high selectivity and sensitivity prepared along with an easy and cost-effective methodology. In the present study, CXM was imprinted onto Hydroxyethyl methacrylate (HEMA) based N‐methacryloyl‐l‐tryptophan (MATrp) containing [p(HEMATrp)] cryogels. MATrp was used as the co-monomer for the preparation of CXM-p(HEMATrp) cryogels. Characterization experiments were performed to analyze the structure of prepared cryogels. Following drug loading and releasing assays, antimicrobial performances CXM-p(HEMATrp) cryogels were investigated against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli. In conclusion, CXM-p(HEMATrp) cryogels have been recommended as potential carriers for further biomedical applications.
Published: 24 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.915115
Staphylococcus aureus, Enterococcus faecalis and Escherichia coli are the common causes of wound infections. For the treatment of these infections, ciprofloxacin can be recommended as a broad-spectrum antibiotic that acts on both Gram-negative and Gram-positive microorganisms. Besides, antimicrobial agents could be integrated into polymeric materials. Cryogels, one of these polymeric materials, are spongy polymers showing high macroporosity. In addition to their attractive usage as affinity support materials and scaffolds, they also appear as drug carrier materials in recent years. Molecular imprinting method is a recognition technique prepared by forming a polymeric network around the template. Although this method has been used in purification and separation processes for more than thirty years, it has gained great interest as a new approach that provides an advantage in drug release studies in terms of high drug loading capacity and long-term release. In this study, ciprofloxacin (CIP) imprinted 2-Hydroxyethyl methacrylate (HEMA) based N-methacryloyl-(L)-histidine methyl ester (MAH) containing [CIP-p(HEMAH)] cryogels was prepared and characterized. CIP releasing experiments were performed, and then, antimicrobial activities of CIP p(HEMAH) cryogels were examined against S. aureus, E. faecalis and E. coli. It can be concluded that CIP-p(HEMAH) cryogels could be proposed as promising polymeric materials for wound healing applications.
Published: 24 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.778023
This study describes the residual mercury levels in canned fish marketed in Turkey. In total, 375 fish samples were analyzed by Inductive Coupled Plasma Optical Emission Spectrometry (ICP OES) for mercury residues. The quantification limit (LOQ) from the validation data ranged from 0.008 to 0.043 mg kg-1. Accuracy and precision were evaluated by means of recovery experiments at two concentration levels (30, and 50 μg L−1), obtaining recoveries between 87.5% and 109.3% and coefficient of variation below 10%. Also, the relative standard deviation (RSD) ranged from 0.2% to 9%. The expanded measurement uncertainty for mercury ranged from 11.1% to 19.2%. In investigated samples, 4.8% were detected at a detectable level of mercury, but these levels were below the legal limits. With regard to hg level were no significant correlations (p < 0.05) between species. According to Turkey's legislation, none of for example the maximum limit of 1.0 mg g-1 did not exceed the level, but 1.3% exceeded the limit recommended by the Food and Agriculture Organization/World Health Organization (0.5 ug g-1). The reproducibility limits obtained as a result of the validation study were found to be appropriate in accordance with both the NMKL 170 method and the Turkish Food Codex (Communiqué No: 2014/2), as well as the EU Commission Decision 2002/657/EC.
Published: 19 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.922633
Son yıllarda, canlılar ve halk sağlığı için önemli bir tehdit oluşturan fenol ve bileşiklerinin tespit edilmesi önem kazanmaktadır. Bu çalışmada, fenolün tespiti için moleküler baskılama yöntemi temel alınarak yüzey plazmon rezonans (SPR) sensörler tasarlanmıştır. Fenol moleküllerine ait boşluklara sahip polimerik film hazırlanarak UV polimerizasyonu ile SPR sensör yüzeyinden oluşturulmuştur. 0.15 ila 10 nM arasındaki tayin aralığında en düşük saptama sınırı 0.011 nM’dir. Ayrıca, biz katekolün yarışmacı ajan olarak seçicilik deneylerini gerçekleştirdik. Genel olarak, moleküler baskılama yaklaşımı ile hazırlanan fenol baskılanmış SPR sensörünün fenol için oldukça hassas ve seçici olduğu bulunmuştur. Fenol baskılı SPR sensörleri, yüksek seçicilikleri, tekrarlayan kullanımları ve hızlı yanıtları özelliği ile mevcut fenol belirleme yöntemlerine yeni bir yöntem olarak kullanılmak düşünülmektedir.
Published: 11 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.921540
The development of new biomaterials is needed to use in many areas such as protein purification, removal and drug release system. In this study, we fabricated hemoglobin (Hb) surface imprinting onto the bacterial cellulose nanofibers. The metal ions coordination was obtained with vinyl imidazole and Ni2+ ions. The selective purification of Hb was obtained using Hb-imprinted bacterial cellulose. The Scanning Electron Microscopy, Surface area, Transformed Infrared Spectroscopy, swelling tests and contact angle measurements were used for the characterization of Hb-imprinted and non-imprinted bacterial cellulose membranes. In addition, the adsorption studies were experimented with using the Hb aqueous solution in the batch systems at 2 h. In this study, the prepared bacterial cellulose was reported unique biomaterials for selective and sensitive purification of Hb with high adsorption capacity. The reusability of bacterial celluloses was demonstrated during the experiment.
Published: 7 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.852492
Group A beta-hemolytic streptococci (GABHS) rank first among bacterial factors causing tonsillopharyngitis. These bacteria are especially common in school-age groups. The incidence increases in winter and seasonal transitions. In this study, we aim to examine the presence of GABHS in throat swab samples of people from different age groups. Therefore, we identified the reproductive frequency of GABHS in the throat culture of patients admitted with tonsillopharyngitis from 2017 to 2019 and then detected differences in the infection across age groups, months, and seasons. It was found that 8.1%, 52.4%, 21.5%, and 11.0% of isolated factors were in the age groups of 0-2, 3-6, 7-9, and 10-14, respectively. Particularly, in the 3-14 age group, the number of cases accounts for 84.9% of the total number of cases. The highest rate of infection was observed in children aged 3-6 years, and the infection was quite high in the spring (34.5%) and winter (29%). Regarding the distribution of the factor across clinics, the Department of Pediatrics was the first, and the Department of Pediatric Nephrology and Rheumatology was the second. In conclusion, controlling the spread of infections at school age is of great importance as GABHS has increased over the years.
Published: 7 May 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.881827
Epoxy-functional porous polyhedral oligomeric silsesquioxane (POSS) microparticles were synthesized by templated polymerization in two-steps by using monodisperse 2µm poly(GMA) seed latex particles as a template. In the first step, templated polymer latex was swollen in emulsion medium to obtain micron size porous POSS particles. In the second step, the hydrophobic monomers metharcyl-POSS, epoxy-functional monomer glycidyl methacrylate (GMA), the crosslinking agent glycerol dimethacrylate (GDMA), and the thermal imitator diffused into the swollen template in emulsion medium for free-radical polymerization. The resultant poly(POSS-co-GDMA-co-GMA) microparticles were obtained in polydisperse form due to the high molecular weight of the silica cage core of POSS created difficulty in the diffusion step. However; monodisperse composite microparticles were obtained around 5.8 ± 0.4µm in size via centrifugal post-separation. The spherical fine porous hybrid structure was fully characterized as morphological, thermal, chemical composition, and crystalline form by SEM, TGA, FTIR, and XRD respectively.
Published: 14 April 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.669854
Improper folding of the mutant proteins may finally cause several conformational diseases such as Nephrogenic Diabetes Insipidus (NDI). In recent years, as a therapeutic strategy, chaperone treatment for such diseases is among current issues. In our study, we aimed to analyze the effect of several chemical chaperones on mutant V2 receptors which cause NDI. V2R mutant constructs were introduced into the pLV2R. Mutants were transiently expressed in COS-7 cells. After MTT analyses, cell surface ELISA experiment was performed for understanding the rescue potential of the chaperones of the mutated proteins. As a result, we analyzed that rescue potential of a chemical chaperone depends on both chemical compound and the mutation type. We may conclude that such chaperone treatment studies are valuable for development of the therapeutic strategies.
Published: 9 April 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.901013
The aim of this study is to determine the protective and therapeutic properties of bee venom components Apamin, Melittin and Phospholipase A2 against UV damage on the human keratinocyte cell line. Cosmetic and therapeutic effects of bee venom have been reported in previous studies, but it is not known which components of the venom have the most effect. For this purpose, firstly, an in vitro UV damage model was designed. Components of bee venom were tested at a different concentration. Cell viability, cytotoxicity and apoptotic processes were analyzed on the designed model. As a result, it has been observed that Apamin demonstrated a significant protective effect against UV-induced cell death at all concentrations. Photoprotective effects of Melittin were observed in all concentration time periods and its photoprotective effects were increased as the concentration increased. Our results were indicated that Phospholipase A2 could be used as a photoprotective and phototherapy agent. This study is the first to show the protective and therapeutic properties of bee venom components against UV damage. As a result, it has been shown that these components can be successful photoprotective and phototherapeutic agents against UV-induced damage, but more detailed studies should be conducted to minimize their toxic effects on cells.
Published: 9 April 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.796377
For this purpose, the use of anesthetic agents is considered as a new alternative. Therefore, in the present study, the effects of propofol which is an intravenous anesthetic on its own and simultaneously with gemcitabine were investigated on human prostate cancer brain metastasis DU145 and bone metastasis PC3 cells at both cellular and molecular levels. In the first stage of our study, toxic doses of these agents were determined by using the CVDK-8 and lactate dehydrogenase release test. In the following phases, TAC and TOS analyzes were performed to determine the biochemical effects of these agents on cell lines, and also western blot analysis was used to show the inhibition of important oncogenic PI3K/AKT/mTOR pathway in cells treated with these agents. Propofol was found to increase the effectiveness of gemcitabine in both cells. When propofol and gemcitabine were administered simultaneously at high concentrations, they reduced cell viability and increased LDH activity. According to the results obtained from the western blot analysis, the combination of these two agents was found to lead to synergistic inhibition of the PI3K/Akt/mTOR pathway.
Published: 9 April 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.795609
A convenient and simple high performance liquid chromatography method for simultaneous separation, determination and identification of levodopa and carbidopa in pharmaceutical formulation has been developed. The analysis was carried out using Ace C18 (4.6 x 250 mm, 5 µm) column, and the separation was performed using a mobile phase consisting of 50 mM KH2PO4 (pH 2.3) pumped at a flow rate of 1.2 mL min-1 with UV detection at 280 nm. The method has been successfully validated on the basis of the International Conference on Harmonization (ICH) acceptance criteria. The method is selective, since no interferences corresponding to these analytes were found at retention times. Retention times for both drugs were 2.939 min and 5.018 for levodopa and carbidopa, respectively. The method was validated and shown to be linear in the concentration range of 25-125 µg mL-1 and 6.25-31.25 µg mL-1 for levodopa and carbidopa, respectively. The method exhibited good linearity (R2 > 0.999) over the assayed concentration range and showed good intra-day and inter-day precision. The limit of detection (LOD) and limit of quantification (LOQ) were determined based on standard deviation of the intercept and the slope of the calibration curve. LOD and LOQ values were 0.70 µg mL-1 and 2.13 µg mL-1 for levodopa and 1.31 µg mL-1 and 3.96 µg mL-1 for carbidopa, respectively. The method's accuracy was tested by adding known volume of standard solution (75 percent, 100 percent, and 125 percent concentration of the sample) to the 100 percent concentration pre-analyzed sample solution. The percentage mean recovery by standard addition experiments of levodopa and carbidopa is 99.75% and 99.55%, respectively. This method has also been successfully used for the determination of levodopa and carbidopa in pharmaceutical formulations.
Published: 15 March 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.817435
In this study, the new benzimidazolium salt (1) containing ether functionalized alkyl group as the NHC ligand precursor was synthesized. Ag-NHC complex (2) was synthesized by interaction with Ag2O of this ligand precursor. The Au-NHC complex was synthesized by interaction the [AuCl(PPh3)] complex with the synthesized Ag-NHC complex. The structures of prepared all new compounds were characterized by different spectroscopic methods. Bu çalışmada, NHC ligand öncüsü olarak eter fonksiyonlu alkil grubu içeren yeni benzimidazol tuzu (1) sentezlendi. Ag-NHC kompleksi (2) bu ligand öncüsünün Ag2O ile etkileştirilmesiyle sentezlendi. Au-NHC kompleksi (3) sentezlenmiş Ag-NHC kompleksi ile [AuCl(PPh3)] kompleksinin etkileştirilmesiyle sentezlendi. Hazırlanan tüm yeni bileşiklerin yapısı farklı spektroskopik metotlar ile karakterize edildi.
Published: 10 March 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.768365
Reseda is an understudied genus regarding germination ecology. We studied the germination response of eight perennial Reseda species to fire related cues by performing a germination experiment including two aqueous smoke treatments (at 1:5 and 1:20 concentrations), one heat shock (100 °C for 5 min.) treatment, and two corresponding controls. Smoke slightly decreased germination percentage in R. aucheri ssp. rotundifolia and R. minoica, and the reduction in R. luteola was statistically significant (P < 0.01). In contrary, smoke promoted germination in R. coodei, R. globulosa, and R. orientalis slightly, and markedly in R. anatolica (from 3 to 11%; P = 0.055). Heat shock treatment did not affect the germination in three of four species tested, but significantly increased germination percentage in R. luteola in comparison to the control (P = 0.046). Consequently, there was no consistent germination response to smoke or heat shock in Reseda species studied. This study is the most comprehensive study tested fire-related germination of several Reseda species and provides the first germination results on seven Reseda species. Further studies that include more species and treatments would show a more completed figure for fire-related germination patterns in the genus Reseda.
Published: 4 March 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.739446
Çekirdek-kabuk nanopartikül sistemler esnek ve sıradışı özellikleri ile başta katalitik dönüşüm olmak üzere farklı alanlarda kullanılmaktadır. Fakat, bu nanosistemleri üretmek için basit, düşük maliyetli ve yenilikçi stratejiler sınırlı sayıda olup, etkin çekirdek-kabuk nanoyapılar yüksek oranda talep görmektedir. Bu çalışmada ince bir polidopamin (PDOP) tabakası ile oluşturulan bimetalik altın ve gümüş çekirdek-kabuk nanosistemin üretimini önermekteyim. PDOP tabakası bir ara tabaka olarak indirgeme ve stabilize ajan olarak etkin bir performans sunmuştur. Bimetalik çekirdek-kabuk sistemin üretimi elektron mikroskop görüntüleri ve UV-vis absorpsiyon spektrası ile doğrulanmıştır. Nanoyapıların katalitik aktivite testleri, 4-nitrofenolün (4-NP) 4-aminofenole (4-AP) indirgenmesi, çekirdek-kabuk sisteminin tepkimenin ilerlemesini arttırdığı gösterilmiştir. Ayrıca, gümüş indirgeme süresinin önerilen nanosistemin katalitik performansı üzerinde önemli etkiye sahip olduğu gözlenmiştir. 60 dakika gümüş indirgeme süresi için 4-NP’nin 4-AP’ye tamamen dönüşümünün sadece 20 dakikada gerçekleştiği görülmüştür.
Published: 4 March 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.788113
The main aim of this study is to determining Meloidae fauna of Ankara. 3301 specimens were collected. 43 species belonging to 2 subfamilies and 15 genera were identified. The genus Mylabris Fabricius, 1775 is the most species-rich genus with 10 species. Cerocoma (s.str.) bernhaueri Pardo Alcaide, 1977, Alosimus luteus (Waltl, 1838), Teratolytta monticola Bologna, 2006, Hycleus polymorphus (Pallas, 1771), H. sexmaculatus (A.G. Olivier, 1811), Mylabris (Micrabris) unicolor Faldermann, 1837, Meloe (Eurymeloe) mediterraneus (G. Muller, 1925) and Stenoria (s.str.) apicalis (Latreille, 1804) species were recorded from Central Anatolian Region of Turkey for the first time. Detailed locality records of M. (Micrabris) unicolor and S. (s.str.) apicalis in Turkey were given with this study for the first time. The most western distributions of Alosimus luteus and Teratolytta monticola were given with this study.
Published: 4 March 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.774575
Antioxidant capacity and essential oil composition of Hypericum thymopsis Boiss. (Hypericaceae), an endemic species, distributed in Turkey was determined. The samples of three different populations were used for the analysis. Antioxidant activities was determined by DPPH method from the leaves and flowers. Essential oil analysis was performed from areal parts of plant by gas chromatography (GC) and GC/mass spectrometry (MS). α-Pinene, spathulenol and limonene are determined as the major components of the essential oils. According to the 50% inhibition (IC50) values (μg/mL) the highest antioxidant values were measured in the methanolic extract of flowers.
Published: 25 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.776430
There are several novel amino acid substitutions in SARS-CoV-2 spike protein, which could account for the increased infectivity of this newly emerged virus. Therefore, in this paper we aimed to evaluate the potential effects of these amino acid substitutions on protein structure and function. For this purpose, we made use of several state-of-the-art computational tools and performed in silico analyses on protein similarity, 2D and 3D structure, ligand binding and biological function. We found that some of the novel amino acid changes caused significant structural alterations both at the secondary and tertiary structure level, possibly affecting the interaction between the spike protein receptor-binding domain (RBD) and ACE2, as well as other ligands. In conclusion, data we provided here is a significant contribution to our current knowledge of the SARS-CoV-2 virus and will aid in having a better understanding of its molecular differences, mechanism of infection and the cellular processes it affects in the host in order to develop better therapies and vaccines.
Published: 16 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.798021
Tiyol grupları içeren aminoasitler olarak Sistein (Cys) ve homosistein (Hcy) biyolojik sistemlerde birçok önemli rol oynamaktadır. HCy’nin plazma seviyesinin, kardiyovasküler ve Alzheimer gibi bazı hastalıkların bir göstergesi olduğu bilinmektedir. Plazmadaki Cys eksikliği karaciğer hasarı, kas ve yağ kaybı, cilt lezyonları, yavaş büyüme vb. Gibi durumlarla ilişkilidir. Bu çalışmada, Cys seviyelerinin belirlenmesi için floresan tabanlı bir metot geliştirilmek üzere yüksek fotolüminesans etkinlik gösteren iridium kompleksleri seçilmiştir. Daha sonra sentezlenen kompleks, Cys çözeltileriyle etkileştirilmiştir. İridyum kompleksiyle etkileşen Cys derişimi arttıkça çözeltinin floresans şiddetinin de arttığı bulunmuştur. Buradan yola çıkarak, sentezlenen iridyum kompleksinin, serum örneklerinde Cys seviyesinin florimetrik tayininde kullanılabileceği düşünülmektedir.
Published: 7 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.649050
Bu çalışmada, taze roka salatasında bulunan polifenoloksidaz (PPO), dietilaminoetil selüloz (DEAE) ile doldurulmuş kolon üzerinden kısmen saflaştırılmıştır. Optimum sıcaklığı 30 °C ve pH 6.0 olarak bulunmuştur. Roka PPO, en yüksek substrat spesifikliğini kullanılan substratlar arasında kateşol ile göstermiştir. Askorbik asit, sistein, okzalik asit ve sitrik asit potansiyel inhbitörler olarak test edilmiştir. En etkili inhibitor sistein olarak belirlenmiştir. Askorbik asit toplam antioksidan aktiviteyi arttırken, kullanılan inhibitörlerin Rokada bulunan fenolik bileşiklerin oksidasyonunu önlediği tespit edilmiştir
Published: 7 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.800069
In recent years, the high frequency of fungal infections originating from Candida and dermatophyte strains has accelerated treatment attempts. Antimicrobial susceptibility test for poly (AN-co-VP) / copolymer, which we think could be an ideal drug in treatment interventions was evaluated with disk diffusion method and minimum inhibitor concentration. In the antimicrobial measurement data, it was determined that the poly (AN-co-VP) / coolymer dissolved in pure water is an significant inhibitory property against the growth of yeast (on Candida spp. with 11.33 ± 0.3 mm barrier area) and dermatophyte fungi (on Epidermophyton sp. and Trichophyton sp. with 12.33 ± 0.3 mm barrier area) (p<0.001) and no inhibitory properties were observed in preventing the growth of all bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus megaterium). MIC limit values that prevent the growth of dermatophytes and yeasts supporting the disc diffusion method are 50-100 μL. This study is an alternative approach in order to limit the spread of superficial fungal infections they cause and eliminate these infections that tend to be come chronic, since this polymer extract has no inhibitory properties on bacteria but prevents the growth of yeast and dermatophytes.
Published: 7 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.725263
DNAJC25 gene is a member of the HSP40 (DNAJ) family, and it was suggested as a tumor suppressor gene in hepatocellular carcinoma. The aim of this study was to analyze the expression, genetic/epigenetic alterations, and prognostic value of the DNAJC25 gene in breast cancer. DNAJC25 transcript levels are upregulated in BT-20 and ZR-75-1 cell lines and downregulated in MDA-MB-231 cell line compared to the non-tumorigenic mammary epithelial cell line (MCF 10A) (P< 0.05). According to UALCAN in-silico tool, clinical breast cancer samples show significantly reduced levels of DNAJC25 mRNA levels relative to the normal samples (P=1.47e-02). The Kaplan–Meier plotter tool shows that high DNAJC25 expression is favorable for post-progression survival in breast cancer (P=0.0035). Point mutations or copy number variations of DNAJC25 are uncommon in clinical breast cancer samples. Combined bisulfite restriction analysis (COBRA) results showed that DNAJC25 promoter is not methylated in breast cell lines. Promoter hypomethylation was also observed in normal and tumor clinical samples (Beta-value < 0.25). In conclusion, DNAJC25 is suggested as a tumor suppressor candidate having limited biomarker potential in breast cancer. Functional studies are essential to reveal its role in breast carcinogenesis.
Published: 7 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.795908
The interest in quantum dot sensitized solar cells (QDSSC), which has theoretically proved to have up to 44% energy conversion efficiency in recent years, is growing rapidly. Although it has theoretically high efficiency value, PCE obtained in studies with QDSSCs is far from these values. This situation shows that there are many difficulties to be solved in QDSSC technology. One of the main challenges in QDSSC technology is irradiated load recombination occurring in QDSSC. For this reason, in this study, it is about using CdSeS QDs as an alternative to the most used CdS QDs in the literature in order to suppress the load recombination between TiO2 surface and electrolyte and QD surfaces. In the study, while CdS and CdSeS QDs were coated on the TiO2 surface with SILAR method, the previously synthesized CdSe QD was coated with chemical deep deposition method. Surfaces were last treated with ZnS QDs. An optimization study was carried out to determine the ideal number of CdSeS coatings for QDSSCs. As a result, the Jsc and Voc values for TiO2/CdSeS4/CdSe/ZnS QDSSCs were 8.799 mA/cm2 and 0.795 V, respectively, while the PCE value increased to 4.452%.
Published: 6 February 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.689397
Many biological processes require cell fusion, therefore defects in cell fusion result in many diseases. The unicellular green alga Chlamydomonas reinhardtii is an excellent model organism to study cell-cell fusion. The objective of this study was to identify genes that are involved in C. reinhardtii mating type minus (MT_) gamete fusion. A forward genetics approach was taken in our work. We created several MT_ fusion defective mutants using DNA insertional mutagenesis. These mutants were normal in the early stages of mating; they agglutinated with mating type plus (MT+), removed their walls, adhered to their mating partner through their mating structures, but the cells did not fuse, indicating that the DNA insertional mutants were defective in the latest stages of fusion. The number of insertions was confirmed by Southern blots. Mutant J1 had one insertion and the flanking genomic DNA was cloned by TAIL-PCR and RESDA-PCR. The insertion is in a gene predicted to be involved in 5-deoxystrigol biosynthesis.
Published: 29 January 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.691065
Başlanğıç malzemesi olarak farklı yapıları ve morfolojiler olan bileşikler kullanılarak sol-gel yöntemiyle demir, aluminium, stronsiyum ve silisyum içeren bir dizi inorganik pigment hazırlanmıştır. Bileşiklerin sentezi, modifiye edilmiş sitrat metodu kullanılarak gerçekleştirildi. Tüm tozlar bir kül fırınına yerleştirildi ve 1150 °C’de 6 saat süreyle havada kalsine edildi, Fe, Sr, Al ve Si’un oksitlerini içeren toz örnekler elde edildi. Sentezlenen beş inorganik pigmentin yapısı, kimyasal bileşimi karşılaştırmalı olarak Fourier dönüşümü kızılötesi spektroskopisi (FTIR), ultraviole-görünür spektroskobisi (UV-vis), X ışını kırınımı (XRD), taramalı elektron mikroskobu (SEM) ve enerji Dağıtıcı X-Ray Analizi(EDX) ile incelenmiştir.
Published: 18 January 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.686550
Published: 18 January 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.689446
Published: 18 January 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.717600
Published: 5 January 2021
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.687387
Published: 26 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.815414
Published: 24 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.696762
Published: 22 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.836685
Published: 9 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.686166
Published: 9 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.686544
Published: 8 December 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.775093
Published: 9 November 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.656021
Published: 1 November 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.667462
Published: 30 October 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.704959
Published: 29 October 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.649802
Published: 28 October 2020
Hacettepe Journal of Biology and Chemistry, Volume 48, pp 483-506; https://doi.org/10.15671/hjbc.813239
Published: 27 October 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.728686
Published: 21 October 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.813565
Published: 16 October 2020
Hacettepe Journal of Biology and Chemistry; https://doi.org/10.15671/hjbc.801427
The term biomimetic can be simply defined as the examination of nature. The scientists inspired by the enormous diversity of nature to solve human problems or facilitate daily life by mimicking natural models, systems, and elements especially in the biomedical and therapeutic applications to make better drugs, artificial organs, sensing instruments, etc. Biological recognition elements like proteins, antibodies, enzymes, DNA, lectins, aptamers, cells, and viruses have been heavily used to ensure specificity in such applications in spite of their lack of stability and reusability. However, in the last two decades molecularly imprinted polymers, MIPs, have been synthesized as an alternative to mimic natural biological interactions for a broad spectrum of templates by means of coordinating functional monomers around template in the presence of cross-linker. This review will outline the broad contours of biomimetics prepared by molecular imprinting techniques and their practical applications in the separation techniques, tissue engineering applications, biomimetic surfaces, sensors, artificial membranes, and drug delivery systems.