title: Purification and Characterisation of a Fibrinolytic Enzyme fromRhizopus microsporusvar.tuberosus.
abstract: Extracellular fibrinolytic enzyme fromRhizopus microsporusvar.tuberosuswas purified and characterised. The microorganism was isolated in a distillery from daqu, a fermentative agent used in the production of Chinese liquor and vinegar at different temperatures. The fibrinolytic enzyme was partially purified by ammonium sulphate precipitation, dialysis, DEAE Sepharose®Fast Flow ion exchange chromatography and Sephadex G-75 gel ﬁltration chromatography. The molecular mass of the fibrinolytic enzyme was estimated to be 24.5 kDa by SDS-PAGE. The purified enzyme showed optimal activity at pH=7.0 and 37 °C by fibrin plate method. It showed stronger resistance to the inhibition by trypsin and was stable at 37 °C retaining 96.1% residual activity after 4 h of incubation. The fibrinolytic activity of the enzyme was enhanced by Na+, Ca2+, Mg2+and Mn2+. Conversely, Zn2+and Cu2+partly inhibited enzymatic activity. Using fibrin plate method, we found that the enzyme not only degrades fibrin directly, but also activates plasminogen into plasmin to degrade fibrin. The results indicate that the pure enzyme has a potential in dissolving blood clot, and the possibility for application in the treatment of thrombosis.
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Shuli
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Yingdong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Xingnan
authors.initials: X
authors.lastname: Cao
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
authors.forename: Haikuan
authors.initials: H
authors.lastname: Wang
keywords: Rhizopus microsporus var. tuberosus; characterisation; fibrinolytic enzyme; purification