Enhanced thermal stability of an alkaline protease, AprP, isolated from a Pseudomonas sp. by mutation at an autoproteolysis site, Ser-331.
The thermal stability of the alkaline protease extracellular subtilisin-type serine protease (AprP) from Pseudomonas sp. KFCC 10818 was improved by altering an amino acid residue at an autoproteolytic cleavage site. N-terminal sequence analysis of the autoproteolytic products of the protein revealed the presence of two cleavage sites, Ser-307 and Ser-331. To increase the thermal stability of the enzyme, serine residues of these sites were replaced with aspartate. The S331D mutant enzyme was successfully purified and characterized whereas the S307D mutant was not. The half-lives of the S331D mutant at 55 degrees C and 60 degrees C were 1.5 and 2.4 times longer than that of the wild-type enzyme, respectively. In addition, the catalytic efficiency was also enhanced.
Jang
J W
JW
BioMedical Research Center, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea.
Ko
J H
JH
Kim
E K
EK
Jang
W H
WH
Kang
J H
JH
Yoo
O J
OJ
D000469:Alkaline Phosphatase; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D001224:Aspartic Acid / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins; D001665:Binding Sites / Q000235:genetics; D004795:Enzyme Stability / Q000235:genetics; D006358:Hot Temperature; D006868:Hydrolysis; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011549:Pseudomonas / Q000201:enzymology* / Q000235:genetics; D012694:Serine / Q000235:genetics* / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D001426:Bacterial Proteins; D001224:Aspartic Acid; D012694:Serine; D000469:Alkaline Phosphatase; C099349:AprP protease, Pseudomonas; D012697:Serine Endopeptidases