Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Biophys Chem. 2018 Jun;237:31-37. doi: 10.1016/j.bpc.2018.03.002. Epub 2018 Mar 22.
The thermal stability of apo α-lactalbumin (α-LA) and lysozyme was measured in the presence of mixtures of glucose, fructose, and galactose. Mixtures of these monosaccharides in the appropriate stoichiometric ratio were found to have a greater stabilizing effect on each of the two proteins than equal weight/volume concentrations of di- tri- and tetrasaccharides with identical subunit composition (sucrose, trehalose, raffinose, and stachyose). The excluded volume model for the effect of a single saccharide on the stability of a protein previously proposed by Beg et al. [Biochemistry 54 (2015) 3594] was extended to treat the case of saccharide mixtures. The extended model predicts quantitatively the stabilizing effect of all monosaccharide mixtures on α-LA and lysozyme reported here, as well as previously published results obtained for ribonuclease A [Biophys. Chem. 138 (2008) 120] to within experimental uncertainty.
在葡萄糖、果糖和半乳糖混合物的存在下，测量了脱辅基α-乳白蛋白（α-LA）和溶菌酶的热稳定性。发现这些单糖的混合物以适当的化学计量比对两种蛋白质都具有比具有相同亚基组成的二糖、三糖和四糖（蔗糖、海藻糖、棉子糖和水苏糖）的等重量/体积浓度更大的稳定作用。贝格等人先前提出的用于单糖对蛋白质稳定性影响的排除体积模型[Biochemistry 54 (2015) 3594]被扩展来处理糖混合物的情况。扩展模型定量预测了这里报道的所有单糖混合物对α-LA 和溶菌酶的稳定作用，以及之前在核糖核酸酶 A 上获得的结果[Biophys. Chem. 138 (2008) 120]，在实验不确定性范围内。
