Conformational changes in bovine lactoferrin induced by slow or fast temperature increases
- 1 August 2008
- journal article
- Published by Walter de Gruyter GmbH in Biological Chemistry
- Vol. 389 (8), 1137-1142
- https://doi.org/10.1515/bc.2008.116
Abstract
Lactoferrin (LF) is an iron-binding protein present in several secreted substances, such as milk, and has broad antimicrobial and physiological properties. Because high temperatures may affect protein stability and its functional properties, we investigated the effect of heat on bovine LF structure and stability. The effects of temperatures used during the pasteurization process on LF and its relationship to protein functionality were studied. Conformational changes were monitored using spectroscopic techniques, such as circular dichroism (CD) and fluorescence spectroscopy. The CD data at 70°C showed that LF's secondary structure is drastically and irreversibly affected when the temperature is gradually increased. The same effect is observed when the temperature is gradually raised from 25°C to 105°C and changes are monitored by tryptophan fluorescence emission. We also verified the effects of simulating the pasteurization process; LF remained well structured during the entire process and this result was not time-dependent. Owing to preservation of the secondary structure with changes in the tertiary structure, we thus believe that pasteurization might cause LF to change into an intermediate partially folded state. A better understanding of heat stability is important for the use of LF as a bioactive component in food.Keywords
This publication has 23 references indexed in Scilit:
- Stabilization of partially folded states in protein folding/misfolding transitions by hydrostatic pressureBrazilian Journal of Medical and Biological Research, 2005
- Sensitivity of the folding/unfolding transition state ensemble of chymotrypsin inhibitor 2 to changes in temperature and solventProtein Science, 2005
- New Insights into the Mechanisms of Protein Misfolding and Aggregation in Amyloidogenic Diseases Derived from Pressure StudiesBiochemistry, 2004
- Nomenclature of the Proteins of Cows’ Milk—Sixth RevisionJournal of Dairy Science, 2004
- Lactoferrin—a multifunctional protein with antimicrobial propertiesMolecular Immunology, 2003
- The application of circular dichroism to studies of protein folding and unfoldingBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1997
- MOLMOL: A program for display and analysis of macromolecular structuresJournal of Molecular Graphics, 1996
- Antiviral Effects of Plasma and Milk Proteins: Lactoferrin Shows Potent Activity against Both Human Immunodeficiency Virus and Human Cytomegalovirus Replication In VitroThe Journal of Infectious Diseases, 1995
- Three-Dimensional Structure of Lactoferrin in Various Functional StatesAdvances in experimental medicine and biology, 1994
- Heat Stability of Bovine Lactoferrin at Acidic pHJournal of Dairy Science, 1991