title: Biochemical characteristics of a fibrinolytic enzyme purified from a marine bacterium, Bacillus subtilis HQS-3.
abstract: A fibrinolytic enzyme isolated from marine Bacillus subtilis HQS-3 was purified to electrophoretic homogeneity using ammonium sulphate precipitation, alkaline solution treatment, membrane concentration, dialysis, ion exchange, and gel filtration chromatography. SDS-PAGE and gel filtration chromatography showed that it was a monomeric protein with an apparent molecular weight of 26 kDa. The purified enzyme was active at pH 6.0-10.0 with an optimum pH of 8.0. It was stable at temperatures ranging from 25 to 37 °C, exhibiting maximum activity between 45 °C and 50 °C. The isoelectric point of the enzyme was 9.0-9.2, which was higher than those of other known fibrinolytic enzymes from Bacillus species. PMSF, EDTA, Cu(2+), Zn(2+), and Co(2+) inhibited the enzyme activity significantly. This enzyme did not cause hemolysis in vitro and preferred direct degradation of fibrin in the following order: α, β, and γ-γ chains. Thus, these results suggest that the marine-derived enzyme is a plasmin-like serine metalloprotease, which is distinct from other fibrinolytic enzymes from genus Bacillus.
authors.affiliation: College of Life Science and Technology, Guangxi University, Nanning 530004, China.
authors.forename: Shihai
authors.initials: S
authors.lastname: Huang
authors.forename: Shihan
authors.initials: S
authors.lastname: Pan
authors.forename: Guiguang
authors.initials: G
authors.lastname: Chen
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Liang
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005337:Fibrin / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D005343:Fibrinolytic Agents; D008670:Metals; D005337:Fibrin
keywords: Bacillus subtilis; Fibrinolytic activity; Plasmin-like serine metalloprotease