基于34条微生物脂肪酶序列,用多元逐步回归法分析了影响脂肪酶最适温度的氨基酸及其二联体。结果表明:与最适温度呈正相关性的氨基酸是Y,负相关性的有I、S、K;呈正相关性的氨基酸二联体有IR、KS、NY、SA、ST和YR,负相关性的有DK、DY、IS、KA、WS、YS和QI。通过对相关性氨基酸二联体在耐热和不耐热脂肪酶中空间位置的分析发现:与最适温度呈正相关性的氨基酸二联体多数位于α-螺旋区,且分布在酶蛋白表面;而呈负相关性的多数位于β-折叠区和无规则卷曲区,一般分布于酶蛋白内部,并常出现在多肽链的N或C端。
|
Based on the lipase sequences from 34 kinds of strain,the relation between amino acids and dipeptides with the optimum temperature were built by a stepwise regression method.The results showed that the positively correlated amino acid was Y,while the negatively correlated ones were I,S and K,and that the positive dipeptides were IR,KS,NY,SA,ST,YR,whereas the negative ones were DK,DY,IS,KA,WS,YS,QI.Through analysis of position information of the related dipeptides in thermophilic and mesophilic lipases,it was found that most positive dipeptides were sited in the α-helix and on the surface of lipases,whereas most negative ones were located in the β-strand or coil,which distributed in buried regions of lipases and often existed in the N or C terminus of lipase chains.
|
