Enzymes in organic synthesis: use of subtilisin and a highly stable mutant derived from multiple site-specific mutations
作者:Chi Huey Wong、S. T. Chen、William J. Hennen、Jeffrey A. Bibbs、Y. F. Wang、Jennifer L. C. Liu、Michael W. Pantoliano、Marc Whitlow、Philip N. Bryan
DOI:10.1021/ja00159a006
日期:1990.1
wild-type enzyme to organic synthesis has been demonstrated in the regioselective acylation of nucleosides in anhydrous dimethylformamide (with 65-100% regioselectivity at the 5'-position), in the enantioselective hydrolysis of N-protected and unprotected common and uncommon amino acid esters inmore » water (with 85-98% enantioselectivity for the L-isomer), and in the synthesis of di- and oligopeptides
Expanded structural and stereospecificity in peptide synthesis with chemically modified mutants of subtilisin
作者:Kanjai Khumtaveeporn、Grace DeSantis、J.Bryan Jones
DOI:10.1016/s0957-4166(99)00255-4
日期:1999.7
Employing the strategy of combined site directed mutagenesis and chemicalmodification, we previously generated chemically modified mutantenzymes (CMMs) of subtilisinBacilluslentus (SBL). We now report the use of these SBL-CMMs for peptide coupling reactions. The SBL-CMMs exhibit dramatically altered substrate specificity, including the acceptance of d-amino acid acyl donors, generating dipeptides
Fibrinolytic and Antithrombotic Protease from Spirodela polyrhiza
作者:Hye-Seon CHOI、You-Seon SA
DOI:10.1271/bbb.65.781
日期:2001.1
A fibrinolytic protease was purified from a Chinese herb (Spirodela polyrhiza). The protease has a molecular mass of 145 kDa and 70 kDa in gel filtration and SDS-polyacrlamide gel electrophoresis (PAGE), respectively, implying it is a dimer. Its optimum pH was 4.5-5.0 The enzyme was stable below 42°C and after lyophilization. The enzyme activity was inhibited significantly by leupeptin and aprotinin. The protease hydrolyzed not only fibrin but also fibrinogen, cleaving Aα and Bβ without affecting the γ chain of fibrinogen. It preferentially cleaved the peptide bond of Arg or Lys of synthetic substates (P1 position). The enzyme had an anticoagulating activity measured with activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) tests. It delayed APTT, TT, and PT two times at the concentration of 36, 39, and 128 nM, respectively and this was drastically reduced after heat treatment.