Print Email Facebook Twitter Heat denaturation of soy glycinin Title Heat denaturation of soy glycinin: Influence of pH and ionic strength on molecular structure Author Lakemond, C.M.M. de Jongh, H.H.J. Hessing, M. Gruppen, H. Voragen, A.G.J. Publication year 2000 Abstract The 7S/11S glycinin equilibrium as found in Lakemond et al. (J. Agric. Food Chem. 2000, 48, xxxxxxxx) at ambient temperatures influences heat denaturation. It is found that the 7S form of glycinin denatures at a lower temperature than the 11S form, as demonstrated by a combination of calorimetric (DSC) and circular dichroism (CD) experiments. At pH 7.6, at which glycinin is mainly present in the 11S form, the disulfide bridge linking the acidic and the basic polypeptides is broken during heat denaturation. At pH 3.8, at which glycinin has dissociated partly into the 7S form, and at pH 5.2 this disruption does not take place, as demonstrated by solubility and gel electrophoretic experiments. A larger exposure of the acidic polypeptides (Lakemond et al., 2000) possibly correlates with a higher endothermic transition temperature and with the appearance of an exothermic transition as observed with DSC. Denaturation/aggregation (studied by DSC) and changes in secondary structure (studied by far-UV CD) take place simultaneously. Generally, changes in tertiary structure (studied by near-UV CD) occur at lower temperatures than changes in secondary structure. Chemicals/CAS: Globulins; glycinin, 9007-93-6; Plant Proteins; Soybean Proteins Subject GlycininHeat denaturationIonic strengthPHProtein structureSoypolypeptidevegetable proteinchemistrycircular dichroismfood processingheat treatmentionic strengthnonhumanosmolarityprotein conformationprotein denaturationprotein foldingprotein quaternary structureprotein secondary structureprotein tertiary structureCircular DichroismGlobulinsHeatHydrogen-Ion ConcentrationOsmolar ConcentrationPlant ProteinsProtein ConformationProtein DenaturationSolubilitySoybean ProteinsSoybeansThermodynamics To reference this document use: http://resolver.tudelft.nl/uuid:4a2b4b05-575d-4ab9-9f46-f4a9fc525af0 DOI https://doi.org/10.1021/jf9908704 TNO identifier 235585 ISSN 0021-8561 Source Journal of Agricultural and Food Chemistry, 48 (48), 1991-1995 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.