Further characterization of earthworm serine proteases: cleavage specificity against peptide substrates and on autolysis.
Cleavage specificity of two fibrinolytic enzymes from Lumbricus rubellus [Nakajima, N., et al., Biosci. Biotechnol. Biochem., 57, 1726-1730 (1993) and 60, 293-300 (1996)] was investigated using beta-amyloid 1-40 and oxidized insulin B-chain as peptide substrates. The serine protease, F-III-2, cleaved the former substrate at six sites, and the latter at five sites. F-II digested them at six and ten, respectively. The cleavage specificity of F-III-2 resembled those of both trypsin and chymotrypsin. F-II had a broader specificity than F-III-2 and preferred also the bonds consisting neutral or hydrophobic amino acids. Furthermore, F-III-2 itself was digested initially on the site of Arg(144)-Tyr(145) to produce two peptide fragments, when it was autolyzed regularly by heating.
Nakajima
N
N
Department of Nutritional Science, Okayama Prefectural University, Japan. nakajima@fhw.oka-pu.ac.jp
Sugimoto
M
M
Ishihara
K
K
Nakamura
K
K
Hamada
H
H
D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002918:Chymotrypsin / Q000378:metabolism; D007328:Insulin / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009835:Oligochaeta / Q000201:enzymology*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism*; D013379:Substrate Specificity; D014357:Trypsin / Q000378:metabolism
D016229:Amyloid beta-Peptides; D007328:Insulin; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D012697:Serine Endopeptidases; D002918:Chymotrypsin; D014357:Trypsin