人乳中蛋白质的组成分析

在对人乳样品分离与纯化的基础上，采用“Bottom Up”并结合高效液相色谱（HPLC）和配有纳米喷雾（Nano-spray）技术的高分辨傅里叶变换离子回旋共振质谱（FT-ICR-MS），将人乳各部分蛋白质样品酶解成多肽片段。 利用碰撞活化解离（CAD）和电子捕获解离（ECD）2种解离方式断裂机理的互补性规律，借助Mascot软件数据库，快速分析了人乳样品中乳脂部分、乳清部分和乳粒部分所含主要蛋白质的组成。人乳样品各部分的共同物性是均含有多种角蛋白、乳白蛋白、乳铁蛋白，但含量和种类各有不同，这既表明了人乳特殊的营养成分，又从另一角度显示出人乳各个部分营养价值的差异。

Composition Analysis of Proteins in Human Milk

“Bottom Up” analysis strategy, combined with HPLC and nano spray Fourier transfrom ion cyclotron resonance mass spectrometry(FT-ICR-MS) technology, was applied to the fragmentation of different proteins separated and purified from human milk. With the high sensitivity and dynamic range of FT-ICR-MS, the detection of different peptide fragmentations in proteins at lowlevels could be fulfilled. Taking advantage of the protein database in the Mascot search engine, the compositions of the major proteins in the fat, whey and pellet parts can be determined efficiently on the basis of complementary relationship of fragmented polypeptides by collisional activated dissociation(CAD) and electron capture dissociation(ECD) techniques. The result shows that keratin, albumin(ALB) protein and lactotransferrin were contained in all the three parts but with different types and quantities, suggesting the nutrition difference among these three parts in human milk.