罗伊氏乳杆菌发酵液中具有降胆固醇能力蛋白的分离、纯化和鉴定

Isolation,purification and identification of protein with cholesterolreducing activity from the supernatant of Lactobacillus reuteri

罗伊氏乳杆菌DSM122460无细胞上清发酵液(cell-free supernatant,CFS)具有较高的胆固醇移除能力,经初步鉴定有效成分为蛋白质。通过超滤浓缩、硫酸铵分级沉淀、DEAE Sepharose F.F阴离子交换层析进一步对该活性成分进行分离纯化。纯化后,其比活力达到61.6 U/mg,纯化倍数为32.4。经SDS-PAGE检测,样品达到电泳级纯,分子量约为60 ku。通过质谱鉴定初步认定该活性蛋白为一假设蛋白,其功能尚待进一步研究。

The cell- free supernatant （CFS） of Lactobacillus reuteri DSM122460 exhibited the cholesterol removal ability and the effective components were predicted as proteins. The active component was purified by ultrafiltration,ammonium sulfate precipitation, and DEAE-Sepharose F.F anion exchange chromatography. The specific activity of purified component was 61.6 U/rag with a purification factor of 32.4.The purified protein was electrophoresis pure determined by SDS-PAGE,and the estimated molecular weight was about 50 ku.The active protein was identified as a hypothetical protein by mass spectrometry and its function remains to be further studied.