Open AccessDesign and evaluation of novel bivalent thrombin inhibitors based on amidinophenylalanines
Author(s) -
Steinmetzer Torsten,
Renatus Martin,
Künzel Sebastian,
Eichinger Andreas,
Bode Wolfram,
Wikström Peter,
Hauptmann Jörg,
Stürzebecher Jörg
Publication year - 1999
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1999.00742.x
Subject(s) - linker , chemistry , thrombin , stereochemistry , medicine , platelet , computer science , immunology , operating system
Two bivalent thrombin inhibitors were synthesized, which consist of a benzamidine‐based active‐site‐blocking segment, a fibrinogen recognition exosite inhibitor and a peptidic linker connecting these fragments. BZA‐1 hirulog contains an N α ‐(2‐naphthylsulfonyl)‐ S ‐3‐amidinophenylalanyl‐isonipecotic acid residue connected via the carboxyl group to the linker segment. The active‐site‐directed moiety of BZA‐2 hirulog [ N α ‐(2‐naphthylsulfonyl‐glutamyl)‐ R ‐4‐amidinophenylalanyl‐piperidide] was coupled to the linker via the side chain of the glutamic acid. Both BZA‐hirulogs contain almost identical linker‐exo site inhibitor parts, except for the substitution of a glycine as the first linker residue in BZA‐1 hirulog by a γ‐amino butyric acid in BZA‐2 hirulog, thus increasing flexibility and linker length by two additional atoms. BZA‐1 hirulog showed moderate potency ( K i = 0.50 ± 0.14 n m ), while BZA‐2 hirulog was characterized as a slow, tight binding inhibitor of thrombin ( K i = 0.29 ± 0.08 p m ). The stability in human plasma of both analogs was strongly improved compared with hirulog‐1. For BZA‐2 hirulog a significantly reduced plasma clearance was observed after intravenous injection in rats compared with BZA‐1 hirulog and hirulog‐1. The X‐ray structure of the BZA‐2 hirulog in complex with human α‐thrombin was solved and confirmed the expected bivalent binding mode.