Poon S, Clarke AE, Schultz CJ
School of Botany, University of Melbourne, Parkville, Victoria, 3052, Australia
J Colloid Interface Sci. 1999 May 1;213(1):193-203. doi: 10.1006/jcis.1998.6057.
Apomyoglobin was chosen as a model to study the emulsifying properties of proteins. It was cleaved into three peptides using cyanogen bromide and these peptides were purified and tested for emulsifying and interfacial properties. Two of the peptides had improved emulsifying activity compared to the whole protein. The peptide (residues 1-55) with the highest emulsifying activity and whole apomyoglobin were studied further. The amount of protein or peptide adsorbed at the oil-water interface of an emulsion was measured and the surface area occupied per molecule was calculated. For apomyoglobin, at maximal surface coverage each molecule occupied a surface area of approximately 8 nm2. This is consistent with a packed monolayer, based on the approximate dimensions of apomyoglobin. For peptide (1-55), at maximal surface coverage each molecule occupied a surface area of approximately 3 nm2. This is consistent with the area that the two amphipathic alpha-helices which are potentially present in this molecule would cover, if they were aligned along the oil-water interface. The different structural characteristics of these molecules responsible for their emulsifying properties are discussed. Copyright 1999 Academic Press.
选择去肌红蛋白作为模型来研究蛋白质的乳化特性。使用溴化氰将其切割成三个肽段，对这些肽段进行纯化并测试其乳化和界面特性。与完整蛋白质相比，其中两个肽段具有更高的乳化活性。对具有最高乳化活性的肽段（残基1 - 55）和完整的去肌红蛋白进行了进一步研究。测量了乳液油水界面处吸附的蛋白质或肽段的量，并计算了每个分子占据的表面积。对于去肌红蛋白，在最大表面覆盖率下，每个分子占据的表面积约为8 nm²。基于去肌红蛋白的大致尺寸，这与紧密排列的单分子层一致。对于肽段（1 - 55），在最大表面覆盖率下，每个分子占据的表面积约为3 nm²。如果该分子中潜在存在的两个两亲性α - 螺旋沿着油水界面排列，这与它们所覆盖的面积一致。讨论了这些分子不同的结构特征与其乳化特性之间的关系。版权所有1999年学术出版社。
