Identification of amino acid residues essential for the catalytic reaction of Bacillus kaustophilus leucine aminopeptidase.
The functional significance of amino acid residues Lys-265, Asp-270, Lys-277, Asp-288, Asp-347, Glu-349, and Arg-351 of Bacillus kaustophilus leucine aminopeptidase was explored by site-directed mutagenesis. Variants with an apparent molecular mass of approximately 54 kDa were overexpressed in Escherichia coli and purified to homogeneity by nickel-chelate chromatography. The purified mutant enzymes had no LAP activity, implying that these residues are important for the catalytic reaction of the enzyme.
Chi
Meng-Chun
MC
Graduate Institute of Biotechnology, National Chiayi University, 60083 Chiayi, Taiwan.
Chou
Wei-Mou
WM
Hsu
Wen-Hwei
WH
Lin
Long-Liu
LL
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001407:Bacillus / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007931:Leucyl Aminopeptidase / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009841:Oligonucleotides / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D009841:Oligonucleotides; D007931:Leucyl Aminopeptidase