Wijayanti Heni B, Bansal Nidhi, Sharma Ranjan, Deeth Hilton C
School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Dairy Innovation Australia Limited, Werribee, VIC 3030, Australia.
Food Chem. 2014 Nov 15;163:129-35. doi: 10.1016/j.foodchem.2014.04.094. Epub 2014 May 4.
The effects of sulphydryl (-SH) reagents on protein aggregation reactions in heated whey protein isolate (WPI) and pure α-lactalbumin (α-La) were investigated. In contrast to its previously reported effect with pure β-Lg, dihydrolipoic acid (DHLA) markedly reduced the heat stability of WPI, especially the α-La component, which aggregated much more readily in the presence of DHLA than in WPI alone. Whilst pure α-La is quite stable to heat, it is much less stable in the presence of DHLA. An effect similar to DHLA was observed with reduced glutathione (GSH). N-ethylmaleimide (NEM), and to a lesser extent, dithio(bis)-p-nitrobenzoate (DTNB), improved the heat stability of WPI; these reagents had little effect on α-La.
研究了巯基（-SH）试剂对加热的乳清蛋白分离物（WPI）和纯α-乳白蛋白（α-La）中蛋白质聚集反应的影响。与之前报道的其对纯β-乳球蛋白的作用相反，二氢硫辛酸（DHLA）显著降低了WPI的热稳定性，尤其是α-La组分，与单独的WPI相比，α-La在DHLA存在下更容易聚集。虽然纯α-La对热相当稳定，但在DHLA存在下其稳定性要低得多。用还原型谷胱甘肽（GSH）观察到了与DHLA类似的效果。N-乙基马来酰亚胺（NEM）以及在较小程度上的二硫代（双）-对硝基苯甲酸（DTNB）提高了WPI的热稳定性；这些试剂对α-La几乎没有影响。
