茯苓发酵液中蛋白质的电泳分离与质谱分析

Electrophoresis separation and MS analysis of proteins in fermentation broth of Poria cocos

目的研究茯苓发酵液中的蛋白质,对其进行分离与鉴定。方法采用液体发酵获得茯苓发酵液,Bradford法测定样品中蛋白质的质量浓度,有机酸沉淀法提取蛋白质,SDS-PAGE电泳分离蛋白质,蛋白质电泳片段进行胶内酶解、质谱分析和搜库鉴定。结果茯苓发酵液中蛋白质的质量浓度为74.01μg/m L,其相对分子质量（M）主要分布在2.8×10^4-1.3×10^5。通过质谱鉴定从茯苓发酵液中鉴定得到了51种蛋白质,如过氧化氢酶、蛋白激酶、碱性蛋白酶、糖化酶和溶菌酶等。结论茯苓发酵液中蛋白质种类丰富,是开展茯苓蛋白质研究及开发茯苓发酵保健食品与饮料的理想材料。

Objective In order to carry out the study on proteins from Poria cocos fermentation broth, the proteins in the fermentation broth were separated and identified. Methods Proteins were obtained by organic acid precipitation from the fermentation broth and the protein concentration was determined by Bradford method. The obtained P. cocos secreted proteins were separated on SDS-PAGE electrophoresis, subjected to in-gel digestion, then identified by mass spectrometric analysis followed by database searching. Results The protein concentration in the fermentation broth was around 74.01 μg/m L, with the apparent molecular weight ranged from 2.8 × 10^4 to 1.3 × 10^5. A total of 52 P. cocos secreted proteins were identified, including catalase, protein kinase, alkaline protease, glucoamylase, lysozyme, and so on. Conclusion P. cocos fermentation broth has abundant proteins, which could be a good material for the study of P. cocos protein and also a potential healthy food and beverage.