1may
BETA-TRYPSIN PHOSPHONATE INHIBITED
OverviewOverview
X-ray structures of trypsin from bovine pancreas inactivated by diphenyl [N-(benzyloxycarbonyl)amino](4-amidinophenyl)methanephosphonate [Z-(4-AmPhGly)P(OPh)2] were determined at 113 and 293 K to 1.8 angstrom resolution and refined to R factors of 0.211 (113 K) and 0. 178 (293 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-stereoisomer of the inhibitor forms contacts with several residues in the trypsin active site. One of the phosphonate oxygens is inserted into the oxyanion hole and forms hydrogen bonds to the amides of Gly193, Asp194, 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 amide forms a hydrogen bond to the carbonyl oxygen atom of Ser214. The inhibitor moiety, from the 113 K structure of trypsin inactivated by the reaction product of Z-(4-AmPhGly)P(OPh)2, was docked into human thrombin [Bode, W., Mayr, I., Baumann, U., Huber, R., Stone, S. R., & Hofsteenge, J. (1989) EMBO J. 8, 3467-3475] and energy minimized. The inhibitor fits well into the thrombin active site, forming favorable contacts similar to those in the trypsin complex with no bad contacts.
About this StructureAbout this Structure
1MAY is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
ReferenceReference
Inhibition of trypsin and thrombin by amino(4-amidinophenyl)methanephosphonate diphenyl ester derivatives: X-ray structures and molecular models., Bertrand JA, Oleksyszyn J, Kam CM, Boduszek B, Presnell S, Plaskon RR, Suddath FL, Powers JC, Williams LD, Biochemistry. 1996 Mar 12;35(10):3147-55. PMID:8605148 Page seeded by OCA on Sat May 3 00:50:25 2008