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
Purification and Characterization of a Novel Extracellular Tripeptidyl Peptidase from Rhizopus oligosporus
作者:Jia-Shin Lin、Shuo-Kang Lee、Yeh Chen、Wei-De Lin、Chao-Hung Kao
DOI:10.1021/jf201879e
日期:2011.10.26
A novel extracellular tripeptidyl peptidase (TPP) was homogenously purified from the culture supernatant of Rhizopusoligosporus by sequential fast protein liquid chromatography. The purified enzyme was a 136.5 kDa dimer composed of identical subunits. The effects of inhibitors and metal ions indicated that TPP is a metallo- and serine protease. TPP was activated by divalent cations, such as Co2+ and
The effects were assessed of high hydrostatic pressure on the activity and structure of rabbit skeletal muscle proteasome. The pressure effects on the activity were measured by the amount of fluorometric products released from synthetic substrates under pressure and from fluorescein isothiocyanate (FITC)-labeled casein after releasing the pressure. The effects on the structure were measured by fluorescene spectroscopy under pressure, and by circular dichroism (CD) spectroscopy and surface hydrophobicity after releasing the pressure. The optimal pressure for the hydrolyzing activity of synthetic peptides was 50 MPa. The degradation of FITC-labeled casein increased linearly with increasing pressure applied up to 200 MPa, and then markedly decreased up to at 400 MPa.The changes in the tertiary structure detected by fluorometric measurement were irreversible, whereas the changes in the secondary structure were small compared with those by heat treatment. The pressure-induced activation of proteasome therefore seems to have been due to a little unfolding of the active sites of proteasome.
申请人:THE RESEARCH FOUNDATION OF
STATE UNIVERSITY OF NEW YORK
公开号:EP0292708A2
公开(公告)日:1988-11-30
The present invention relates to the detection of B. gingivalis by the specific ability of B. gingivalis to hydrolyze N-carbobenzoxy-glycyl-glycyl-L-arginine-B-napthylamide derivatives. The present invention also relates to the use of assay systems which inhibit serum amino peptidase and enhance the detection of the B. gingivalis N-CBz-Gly-Gly-Arg peptidase. The assay system inhibits the serum enzyme by the use of a serum aminopeptidase inhibitor which inhibits the activity of serum aminopeptidase to a greater extent than it inhibits the activity of B. gingivalis N-CBz-Gly-Gly-Arg peptidase. The assay system also increases the reliability of detection of the B. gingivalis enzyme by the use of enhancing materials which enhance the enzyme activity of B. gingivalis N-CBz-Gly-Gly-Arg peptidase to a greater extent than such materials enhance the enzyme activity of serum aminopeptidase.