Paenibacillus spp.BD3526金属蛋白酶对乳蛋白水解位点分析

Analysis of Cleavage Sites in Bovine Milk Proteins by Metalloproteinase(M4) from Paenibacillus spp.BD3526

为了比较具有凝乳功能的Paenibacillus spp.BD3526来源的金属蛋白酶与基因重组凝乳酶对乳蛋白水解位点的差异,采用BD3526金属蛋白酶和凝乳酶对α_(s1)-酪蛋白(casein,CN)、α_(s2)-CN、β-乳球蛋白(lactoglobulin,Lg)和κ-CN进行酶解,分别对不同时间的酶解产物采用高效液相色谱与四极杆飞行时间串联质谱(high performance liquid chromatography of quadrupole time of flight-tandem mass spectrometry,HPLC-Q-TOF-MS/MS)进行分析。结果表明:BD3526金属蛋白酶与凝乳酶在对乳蛋白的水解位点上具有较高的相似性,前者对α_(s1)-CN、α_(s2)-CN、β-Lg和κ-CN水解能力较后者弱,对P1为K(Lys)、R(Arg)且P1'为T(Thr)、F(Phe)和Y(Tyr)间的肽键水解特异性很高,并主要水解K-T(Lys-Thr)、K-F(Lys-Phe)、R-F(Arg-Phe)、R-Y(Arg-Tyr)肽键,水解生成的肽具有血管紧张素转换酶(angiotensin converting enzyme,ACE)抑制、抗菌、免疫调节等功能。

In order to find the difference between the cleavage sites in bovine milk proteins by metalloproteinase from Paenibacillus spp.BD3526 and chymosin,the peptides generated from αs1-,αs2- and κ-casein and β-lactoglobulin（β-Lg） digested by the enzymes were analyzed by high performance liquid chromatography coupled with quadruple-timeof-flight mass spectrometer（HPLC-Q-TOF-MS-MS）.The results indicated that the cleavage sites in bovine milk proteins by metalloproteinase and chymosin shared high similarity and both of these enzymes specifically cleaved the Lys-Thr,Lys-Phe,ArgPhe and Arg-Tyr peptide bonds to generate peptides with ACE inhibitory,antimicrobial and immunomodulating activities.