Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
J Agric Food Chem. 2011 Sep 14;59(17):9605-11. doi: 10.1021/jf2020057. Epub 2011 Aug 4.
In this study, in vitro digestion of β-lactoglobulin (β-Lg) fibrils and the re-formation of fibril-like structures after prolonged enzymatic hydrolysis (up to 48 h) were investigated using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), thioflavin T fluorescence photometry, and transmission electron microscopy (TEM). Pure β-Lg fibrils that had been formed by heat treatment at pH 2.0 were rapidly hydrolyzed by pepsin in the simulated gastric fluid (pH 1.2), and some new peptides that were suitable for further fibril formation were produced. TEM showed that the new fibrils were long and straight but thinner than the original fibrils, and both TEM and MALDI-MS indicated that the peptides in the new fibrils were shorter/smaller than the peptides in the original fibrils. The formation of new fibrils was found to be affected more by pH than by enzyme activity or temperature.
在这项研究中，使用基质辅助激光解吸/电离质谱（MALDI-MS）、硫黄素 T 荧光光度法和透射电子显微镜（TEM）研究了β-乳球蛋白（β-Lg）纤维在体外消化以及在长时间酶解（长达 48 小时）后的纤维样结构的再形成。通过在 pH 2.0 下热处理形成的纯β-Lg 纤维在模拟胃液（pH 1.2）中被胃蛋白酶迅速水解，并产生了一些适合进一步形成纤维的新肽段。TEM 显示，新纤维又长又直，但比原始纤维更细，TEM 和 MALDI-MS 均表明，新纤维中的肽段比原始纤维中的肽段更短/小。结果发现，新纤维的形成受 pH 的影响比受酶活性或温度的影响更大。
