Production of Dihydrofolate Reductase by ClonedEscherichia coliand Its Application to Asymmetric Synthesis ofl-Leucovorin
摘要:
We have investigated culture conditions for production of dihydrofolate reductase by Escherichia coli harboring a high expression plasmid, pTP64–1. Sorbitol addition and pH control were effective for the production of the enzyme in a jar fermentor. The enzyme was purified from a cell-free extract by column chromatographies on DEAE-Cellulofine and Superose Prep12 and showed a single band on SDS-polyacrylamide gel electrophoresis.The reduction of 200 mM dihydrofolate to 6(S)-tetrahydrofolate, an intermediate for l-leucovorin synthesis, was complete in 2 hr under anaerobic conditions, using 1.5 units/ml of the purified enzyme.
Probing the Electrostatics of Active Site Microenvironments along the Catalytic Cycle for <i>Escherichia coli</i> Dihydrofolate Reductase
作者:C. Tony Liu、Joshua P. Layfield、Robert J. Stewart、Jarrod B. French、Philip Hanoian、John B. Asbury、Sharon Hammes-Schiffer、Stephen J. Benkovic
DOI:10.1021/ja5038947
日期:2014.7.23
Electrostatic interactions play an important role in enzymecatalysis by guiding ligand binding and facilitating chemical reactions. These electrostatic interactions are modulated by conformational changes occurring over the catalytic cycle. Herein, the changes in active site electrostatic microenvironments are examined for all enzyme complexes along the catalytic cycle of Escherichia coli dihydrofolate
We have investigated culture conditions for production of dihydrofolate reductase by Escherichia coli harboring a high expression plasmid, pTP64–1. Sorbitol addition and pH control were effective for the production of the enzyme in a jar fermentor. The enzyme was purified from a cell-free extract by column chromatographies on DEAE-Cellulofine and Superose Prep12 and showed a single band on SDS-polyacrylamide gel electrophoresis.The reduction of 200 mM dihydrofolate to 6(S)-tetrahydrofolate, an intermediate for l-leucovorin synthesis, was complete in 2 hr under anaerobic conditions, using 1.5 units/ml of the purified enzyme.