title: Purification and characterization of subtilisin DJ-4 secreted by Bacillus sp. strain DJ-4 screened from Doen-Jang.
abstract: Bacillus sp. strain DJ-4, which produces extracellular proteases, was screened from Doen-Jang, a traditional Korean fermented food. A fibrinolytic enzyme (subtilisin DJ-4) was purified using commercial chromatographic techniques. The relative molecular mass of the isolated protein was 29 kDa by SDS-PAGE and fibrin zymography assay. The enzyme was characterized as a serine protease by an inhibitor assay on the fibrin zymography gel and by an amidolytic assay using a chromogenic substrate. The enzyme was inhibited by PMSF, but not by EDTA or leupeptin. The first 14 amino acids of the N-terminal sequence were identical to that of subtilisin BPN', but the activity of subtilisin DJ-4 was 2.2 and 4.3 times higher than those of subtilisin BPN' and subtilisin Carlsberg, respectively.
authors.affiliation: Protein Engineering Group, Korea Research Institute of Bioscience and Biotechnology, Yusong, Taejon. shkim@kribb4680.kribb.re.kr
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: N S
authors.initials: NS
authors.lastname: Choi
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D005342:Fibrinolysis; D005504:Food Analysis; D007723:Korea; D007976:Leupeptins / Q000494:pharmacology; D008970:Molecular Weight; D013381:Subtilisins / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D007976:Leupeptins; D004492:Edetic Acid; D013381:Subtilisins; C032854:leupeptin