INHIBITION OF TRYPSIN AND THROMBIN BY AMINO(4-AMIDINOPHENYL)METHANEPHOSPHONATE DIPHENYL ESTER DERIVATIVES - X-RAY STRUCTURES AND MOLECULAR-MODELS

Citation
Ja. Bertrand et al., INHIBITION OF TRYPSIN AND THROMBIN BY AMINO(4-AMIDINOPHENYL)METHANEPHOSPHONATE DIPHENYL ESTER DERIVATIVES - X-RAY STRUCTURES AND MOLECULAR-MODELS, Biochemistry, 35(10), 1996, pp. 3147-3155
Citations number
52
Categorie Soggetti
Biology
Journal title
ISSN journal
00062960
Volume
35
Issue
10
Year of publication
1996
Pages
3147 - 3155
Database
ISI
SICI code
0006-2960(1996)35:10<3147:IOTATB>2.0.ZU;2-Z
Abstract
X-ray structures of trypsin from bovine pancreas inactivated by diphen yl [N-(benzyloxycarbonyl)amino] (4-amidinophenyl)methanephosphonate [Z -(4-AmPhGly)(P)(OPh)(2)] were determined at 113 and 293 K to 1.8 Angst rom resolution and refined to R factors of 0.211 (113 K) and 0.178 (29 3 K). The Structures reveal a tetrahedral phosphorus covalently bonded to the O gamma of the active site serine. Covalent bond formation is accompanied by the loss of both phenoxy groups. The D-stereoisomer of Z-(4-AmPhGly)(P)-(OPh)(2) is not observed in the complex. The L-stereo isomer of the inhibitor forms contacts with several residues in the tr ypsin active site. One of the phosphonate oxygens is inserted into the oxyanion hole and forms hydrogen bonds to the amides of Gly193, Asp19 4, and Ser195. The second phosphonate oxygen forms hydrogen bonds to N epsilon 2 of His 57. The p-amidinophenylglycine moiety binds into the trypsin primary specificity pocket, interacting with Asp189. The amid e forms a hydrogen bond to the carbonyl oxygen atom of Ser214. The inh ibitor moiety, from the 113 K structure of trypsin inactivated by the reaction product of Z-(4-AmPhGly)(P)(OPh)(2), was docked into human th rombin [Bode, W., Mayr, I., Baumann, U., Huber, R., Stone, S. R., & Ho fsteenge, J. (1989) EMBO J. 8, 3467-3475] and energy minimized. The in hibitor fits well into the thrombin active site, forming favorable con tacts similar to those in the trypsin complex with no bad contacts.