Dimethylallyltryptophan synthase. An enzyme-catalyzed electrophilic aromatic substitution
摘要:
Dimethylallyltryptophan (DMAT) synthase catalyzes the alkylation of L-tryptophan at C(4) by dimethylallyl diphosphate (DMAPP) in the first pathway-specific step in the biosynthesis of ergot alkaloids. The mechanism of the reaction was studied with analogs of both substrates. Five 7-substituted derivatives of N-acetyltryptophan (2, Z = OCH3, CH3, F, CF3, and NO2) were synthesized. The L enantiomers of the free amino acids were obtained by selective hydrolysis of the racemate using aminoacylase from Aspergillus. In addition, the E and Z fluoromethyl and difluoromethyl analogs of DMAPP (1, Y = CH3, CH2F, CHF2) were prepared. Rates of the enzyme-catalyzed reactions were measured for the dimethylallyl derivatives with L-tryptophan and for the L-tryptophan derivatives with DMAPP. In addition, the relative reactivities of the methanesulfonate derivatives of the DMAPP analogs were determined for solvolysis in aqueous acetone. A Hammett plot for the tryptophan analogs gave a good linear correlation with rho = -2.0. In addition, a Hammett plot of the logarithms of the relative rates of solvolysis and enzyme-catalyzed alkylation gave a positive linear correlation. These results indicate that the prenyl-transfer reaction catalyzed by DMAT synthase is an electrophilic aromatic substitution and is mechanistically similar to the electrophilic alkylation catalyzed by farnesyl diphosphate synthase.
[EN] AZASULFURYLPEPTIDE-BASED CD36 MODULATORS AND USES THEREOF<br/>[FR] MODULATEURS CD36 À BASE D'AZASULFURYLPEPTIDES ET UTILISATIONS DE CEUX-CI
申请人:RSEM LTD PARTNERSHIP
公开号:WO2016029324A1
公开(公告)日:2016-03-03
Novel azasulfuryl-containing peptidomimetics capable of inhibiting CD36 activity are disclosed. Use of these azasulfuryl-containing peptidomimetics for the treatment of CD36-related diseases, disorders or conditions, including TLR2-mediated inflammatory disease, disorder or condition, and methods of obtaining such azasulfuryl-containing peptidomimetics, are also disclosed.
Disclosed herein are methods, compositions, probes, assays and kits for identifying a lipid binding protein as a drug binding target. Also disclosed herein are methods, compositions, and probes for mapping a ligand binding site on a lipid binding protein, identification of lipid binding proteins, generating drug-lipid binding protein profiles, high throughput drug screening, and identification of drugs as potential lipid binding protein ligands.
Peptides capable of binding to extracellular matrix proteins, such as collagen, are described, including their use in diagnostic and therapeutic applications.
REAGENTS AND METHODS FOR REPLICATION, TRANSCRIPTION, AND TRANSLATION IN SEMI-SYNTHETIC ORGANISMS
申请人:The Scripps Research Institute
公开号:US20200392550A1
公开(公告)日:2020-12-17
Disclosed herein are compositions, methods, cells, engineered microorganisms, and kits for increasing the production of proteins or polypeptides comprising one or more unnatural amino acids. Further provided are compositions, cells, engineered microorganisms, and kits for increasing the retention of unnatural nucleic acids encoding the unnatural amino acids in an engineered cell, or semi-synthetic organism.