Dihydrofolate reductase(DHFR),a housekeeping enzyme in primary metabolism,has been extensively studied as a model of acid-base catalysis and a clinic drug target.Herein,we investigated the enzymology of a DHFR-like pr...Dihydrofolate reductase(DHFR),a housekeeping enzyme in primary metabolism,has been extensively studied as a model of acid-base catalysis and a clinic drug target.Herein,we investigated the enzymology of a DHFR-like protein SacH in safracin(SAC)biosynthesis,which reductively inactivates hemiaminal pharmacophore-containing biosynthetic intermediates and antibiotics for self-resistance.Furthermore,based on the crystal structure of SacH−NADPH−SAC-A ternary complexes and mutagenesis,we proposed a catalytic mechanism that is distinct from the previously characterized short-chain dehydrogenases/reductases-mediated inactivation of hemiaminal pharmacophore.These findings expand the functions of DHFR family proteins,reveal that the common reaction can be catalyzed by distinct family of enzymes,and imply the possibility for the discovery of novel antibiotics with hemiaminal pharmacophore.展开更多
A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synt...A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synthe- sized as non-classical antifolates in order to overcome drug resistance. The compounds were evaluated for in vitro antitumor activities, rhDHFR and antimicrobial activities. All the compounds exhibited antitumor activities, with ICs0 values in the range of 0.13--17.8 gmol/L against HL-60, HeLa and A549. Both the types of aryl groups and the orientation of polyphenyl aryl made an impact on the biological activities. 6-Naphthylethyl derivatives 5c and 5d were proved to be the most active Dt-IFR inhibitors, which were more potent than 6-phenylethyl, 6-thienylethyl and 6-biphenylethyl derivatives. Docking studies reveal that flexible saturated carbon-carbon bond of C9--C10 is essential for biological activities in molecular backbone. Antimicrobial test shows that most of the compounds exhibit antibacterial activities.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31930002,21621002,21877002,81991525,82273829 and 22077007)the key project at central government level:the ability establishment of sustainable use for valuable Chinese medicine resources(2060302-2201-17).
文摘Dihydrofolate reductase(DHFR),a housekeeping enzyme in primary metabolism,has been extensively studied as a model of acid-base catalysis and a clinic drug target.Herein,we investigated the enzymology of a DHFR-like protein SacH in safracin(SAC)biosynthesis,which reductively inactivates hemiaminal pharmacophore-containing biosynthetic intermediates and antibiotics for self-resistance.Furthermore,based on the crystal structure of SacH−NADPH−SAC-A ternary complexes and mutagenesis,we proposed a catalytic mechanism that is distinct from the previously characterized short-chain dehydrogenases/reductases-mediated inactivation of hemiaminal pharmacophore.These findings expand the functions of DHFR family proteins,reveal that the common reaction can be catalyzed by distinct family of enzymes,and imply the possibility for the discovery of novel antibiotics with hemiaminal pharmacophore.
基金Supported by the National Natural Science Foundation of China（Nos.21172014, 21302007）.
文摘A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synthe- sized as non-classical antifolates in order to overcome drug resistance. The compounds were evaluated for in vitro antitumor activities, rhDHFR and antimicrobial activities. All the compounds exhibited antitumor activities, with ICs0 values in the range of 0.13--17.8 gmol/L against HL-60, HeLa and A549. Both the types of aryl groups and the orientation of polyphenyl aryl made an impact on the biological activities. 6-Naphthylethyl derivatives 5c and 5d were proved to be the most active Dt-IFR inhibitors, which were more potent than 6-phenylethyl, 6-thienylethyl and 6-biphenylethyl derivatives. Docking studies reveal that flexible saturated carbon-carbon bond of C9--C10 is essential for biological activities in molecular backbone. Antimicrobial test shows that most of the compounds exhibit antibacterial activities.
