反相高效液相色谱-电喷雾质谱法分析食源血管紧张素转换酶抑制肽

利用反相高效液相色谱/电喷雾离子阱质谱法,直接分析从牦牛乳酪蛋白中酶水解得到的血管紧张素转换酶抑制肽粗产物。RP-HPLC显示具有活性的多肽粗产物含有3个主要成分,质谱同步测定各组分的分子量(m/z)分别为815.2,1680.1,962.2,然后选择[M H] 离子通过串联质谱(MS/MS)得到碎片离子,利用b离子和y离子互补的方法鉴定了多肽序列。三条肽分别为Leu-Pro-Tyr-Tyr,Pro-Leu-Pro-Leu-Leu-Gln,Phe-Leu-Pro-Pro-Tyr-Tyr。结果显示,所获得的多肽序列与牛乳酪蛋白一级结构中相应肽段的序列一致。

Analysis of Food-derived Angiotensin-Iconverting Enzyme Inhibitory Peptides by Reversed Phase High Performance Liquid Chromatography/Electrospray Mass Spectrometry

Application of reversed phase high performance liquid chromatography (RP-HPLC)/ion trap electrospray mass spectrometry (ESI-MS) to the direct analysis of polypeptides derived from Yak milk casein. RP-HPLC showed that the crude product contained three major components. The accurate molecular weight of each component was determined by the coupled electrospray mass spectrometry and are 815.2, 680.1, 962.2, respectively, then fragmentation ions were obtained by selecting [M H] ion using tandem mass spectrometry (MS/MS), the sequences of the polypeptides were confirmed by using complementary b ion and y ion method, the three polypeptides are Leu-Pro-Tyr-Tyr, Pro-Leu-Pro-Leu-Leu-Gln, Phe-Leu-Pro-Pro-Tyr-Tyr. The results show that the sequences of the polypeptides are in accordance with the corresponding peptides in original milk casein.