扩展青霉碱性脂肪酶的纯化及N-端氨基酸序列分析

Purification and N-terminal Sequencing of an Alkaline Lipase from Penicillium expansum

扩展青霉PF898的发酵液经硫酸铵沉淀、DE5 2纤维素离子交换柱、SephadexG 10 0凝胶过滤等步骤 ,其碱性脂肪酶的活性被纯化了 79.3倍 ,回收率约 15 % ,比活为 76 .9U/mg .纯化蛋白经SDS PAGE和HPLCTSK GELG30 0 0SW凝胶过滤分析显示其分子量约为 2 8kDa .纯化蛋白经氨基酸序列测定仪分析表明 ,其N 端 12个氨基酸的序列为 :A T A D A A A F P D L H .

The alkaline lipase produced by Penicillium expansum PF898 at a high level was purified 79.3-fold by ammonium-sulfated precipitation, DE52 ion exchange chromato-graph and Sephadex G 100 gel filtration to a final specific activity of 76.9U/mg. The molecular weight of the enzyme was about 28 kDa determined by SDS-PAGE and gel filtration. Purified protein was electrophoretically transfered to a PVDF membrane to analysis N-terminal amino acid sequence. The 12 aa of N-terminal are A-T-A-D-A-A-A-F-P-D-L-H and 3 of them are different from the N-terminal sequence of P. expansum DSM1994:V-A-A-S-A-A-F-P-D-L-X. The homologous is about 75% between the two N-terminal sequences.