Origin of the stereospecificity in binding hydroxamates of α- and β-phenylalanine methylamide to thermolysin revealed by the X-ray crystallographic study
摘要:
Optically active N-formyl-N-hydroxy-alpha-phenylalanine methylamide (1) and N-formyl-N-hydroxy-beta-phenylalanine methylamide (2) were evaluated as inhibitors for thermolysin (TLN) to find that while the D-form is more potent than its enantiomer in the case of the hydroxamate of alpha-Phe-NHMe, in the inhibition with hydroxamate of beta-Phe-NHMe, the L-isomer (K-i = 1.66 +/- 0.05 muM) is more effective than its enantiomer. In order to shed light on the stereochemical preference observed in the inhibitions, X-ray crystallographic analyses of the crystalline (TLND)-D-.-1 and (TLNL)-L-.-2 complexes were performed to the resolution of 2.1 Angstrom. While L-2 binds TLN like substrate does with its benzyl aromatic ring occupying the S-1' pocket, the electron density in the S-1' pocket in the complex of (TLND)-D-.-1 is weak and could best be accounted for by the methylcarbamoyl moiety. For both inhibitors, the hydroxamate moiety coordinates the active site zinc ion in a bidentate fashion. (C) 2003 Elsevier Science Ltd. All rights reserved.
Two routes are presented for the conversion of opticallyactive α-amino acidamides into the title compounds. One route(route A) features the formation of the Schiff's base 6 which is subsequently oxidized to the corresponding oxaziridines 7. Route B is characterized by the formation of an imidazolin 11 which is hydroxylated to compound 12. Alcoholysis of 7 and 12 in the presence of hydroxylamine hydrochloride
Origin of the stereospecificity in binding hydroxamates of α- and β-phenylalanine methylamide to thermolysin revealed by the X-ray crystallographic study
作者:Seung-Jun Kim、Dong H Kim、Jung Dae Park、Joo-Rang Woo、Yonghao Jin、Seong Eon Ryu
DOI:10.1016/s0968-0896(03)00140-8
日期:2003.5
Optically active N-formyl-N-hydroxy-alpha-phenylalanine methylamide (1) and N-formyl-N-hydroxy-beta-phenylalanine methylamide (2) were evaluated as inhibitors for thermolysin (TLN) to find that while the D-form is more potent than its enantiomer in the case of the hydroxamate of alpha-Phe-NHMe, in the inhibition with hydroxamate of beta-Phe-NHMe, the L-isomer (K-i = 1.66 +/- 0.05 muM) is more effective than its enantiomer. In order to shed light on the stereochemical preference observed in the inhibitions, X-ray crystallographic analyses of the crystalline (TLND)-D-.-1 and (TLNL)-L-.-2 complexes were performed to the resolution of 2.1 Angstrom. While L-2 binds TLN like substrate does with its benzyl aromatic ring occupying the S-1' pocket, the electron density in the S-1' pocket in the complex of (TLND)-D-.-1 is weak and could best be accounted for by the methylcarbamoyl moiety. For both inhibitors, the hydroxamate moiety coordinates the active site zinc ion in a bidentate fashion. (C) 2003 Elsevier Science Ltd. All rights reserved.