Specificity of alkaline elastase Bacillus on the oxidized insulin A- and B-chains.
The substrate specificity of alkaline elastase Bacillus from alkalophilic Bacillus sp. Ya-B was investigated using oxidized insulin A- and B-chains. Under time-limited cleavage, the initial cleavage site of the enzyme on the oxidized insulin A-chain and B-chain was at the leucine13-tyrosine14 bond and the leucine15-tyrosine16 bond, respectively. When the cleavage was completed, three major cleavage sites and three minor cleavage sites on the A-chain, and five major cleavage sites and four minor cleavage sites on the B-chain were found. However, most of the peptides produced after complete hydrolysis of the A- or B-chain by the enzyme were composed of four to six amino acid residues. The results suggest that this enzyme cleaves the oxidized insulin A- and B-chains in a block-cutting manner.
Tsai
Y C
YC
Institute of Biochemistry, National Yang-Ming Medical College, Taipei, Taiwan.
Lin
Y T
YT
Yang
Y B
YB
Li
Y F
YF
Yamasaki
M
M
Tamura
G
G
D000596:Amino Acids / Q000032:analysis; D001407:Bacillus / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D007328:Insulin / Q000378:metabolism*; D010084:Oxidation-Reduction; D010196:Pancreatic Elastase / Q000378:metabolism*; D013379:Substrate Specificity
D000596:Amino Acids; D007328:Insulin; C042629:alkaline elastase; D010196:Pancreatic Elastase