Hacettepe Journal of Biology and Chemistry

Journal Information
ISSN : 1303-5002
Total articles ≅ 349

Latest articles in this journal

Kadriye Özlem Hamaloglu
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.
Namık KILINÇ, Şükrü Beydemir
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.
Sevda Türkiş, Esra Deniz Candan
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.
Muzaffer Dükel
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.
Duygu Çimen, Adil Denizli
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.
Sevgi Asliyüce Çoban, Neslihan Idil, Adil Denizli
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.
Neslihan Idil, Sevgi Asliyüce Çoban, Adil Denizli
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.
Back to Top Top