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.
Graduate Institute of Biotechnology, National Chiayi University, 60083 Chiayi, Taiwan.
Meng-Chun
MC
Chi
Wei-Mou
WM
Chou
Wen-Hwei
WH
Hsu
Long-Liu
LL
Lin
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