Site-directed mutagenesis of the active site of pectin methylesterase from Aspergillus niger RH5344

被引：9

作者：

Duwe, B ^{[1
]}

Khanh, NQ ^{[1
]}

机构：

[1] TH DARMSTADT,INST BIOCHEM,D-64287 DARMSTADT,GERMANY

来源：

BIOTECHNOLOGY LETTERS | 1996年 / 18卷 / 06期

关键词：

D O I：

10.1007/BF00130754

中图分类号：

Q81 [生物工程学（生物技术）]; Q93 [微生物学];

学科分类号：

071005 ; 0836 ; 090102 ; 100705 ;

摘要：

The role of two histidine residues of pectin methylesterase (PME) were analysed by site-directed mutagenesis. Mutant and wild-type pmeA-cDNA were expressed in A. niger strain NRRL3. Both mutant enzymes exhibited the same mobility on SDS-polyacrylamide gel electrophoresis and gave similar circular dichroism spectra to that of the wild-type enzyme. Substitution of His-137 to alanine caused a loss of PME activity. In contrast, replacement of His-188 had no effect on the PME activity. These results revealed that the histidine residue at position 137 is essential for enzyme activity and probably located in the active site of PME.

引用

页码：621 / 626

页数：6