1no9
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Design of weakly basic thrombin inhibitors incorporating novel P1 binding functions: molecular and X-ray crystallographic studies.
OverviewOverview
To prepare weakly basic thrombin inhibitors with modified S1 anchoring, groups, two series of compounds were synthesized by reaction of guanidine, or aminoguanidine with acyl halides and N,N-disubstituted carbamoyl, chlorides. pK(a) measurements of these acylated guanidines/aminoguanidines, showed a reduced basicity, with pK(a) values in the range of 8.4-8.7., These molecules typically showed inhibition constants in the range of, 150-425 nM against thrombin and 360-965 nM against trypsin, even though, some bulky derivatives, such as, N,N-diphenylcarbamoylguanidine/aminoguanidine and their congeners, showed, much stronger thrombin inhibitory activity, with inhibition constants in, the range of 24-42 nM. Unexpectedly, very long incubation times with both, proteases revealed that aminoguanidine derivatives behaved as irreversible, inhibitors. To assess the molecular basis responsible for the high, affinity observed for these molecules toward thrombin, the crystal, structure of the thrombin-hirugen-N,N-diphenylcarbamoylaminoguanidine, complex has been solved at 1.90 A resolution. The structural analysis of, the complex revealed an unexpected interaction mode with the protease, resulting in an N,N-diphenylcarbamoyl intermediate covalently bound to the, catalytic serine as a consequence of its hydrolysis together with the, release of the aminoguanidine moiety. Surprisingly, in this covalent, adduct a phenyl group was found in the S1 specificity pocket, which, usually recognizes positively charged residues. These findings provide new, insights in the design of low basicity serine protease inhibitors.
DiseaseDisease
Known diseases associated with this structure: Dysprothrombinemia OMIM:[176930], Hyperprothrombinemia OMIM:[176930], Hypoprothrombinemia OMIM:[176930]
About this StructureAbout this Structure
1NO9 is a Protein complex structure of sequences from Homo sapiens with NAG and 4ND as ligands. Active as Thrombin, with EC number 3.4.21.5 Full crystallographic information is available from OCA.
ReferenceReference
Design of weakly basic thrombin inhibitors incorporating novel P1 binding functions: molecular and X-ray crystallographic studies., De Simone G, Menchise V, Omaggio S, Pedone C, Scozzafava A, Supuran CT, Biochemistry. 2003 Aug 5;42(30):9013-21. PMID:12885234
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