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.
View Article and Find Full Text PDFA series of 7-amino-4-chloro-3-(3-isothioureidopropoxy)isocoumarin (NH2-CiTPrOIC) derivatives with various substituents at the 7- and 3-positions have been synthesized as inhibitors of several blood coagulation enzymes. Isocoumarins substituted with basic groups such as guanidino or isothioureidoalkoxy groups were previously shown to be potent irreversible inhibitors of blood coagulation enzymes [Kam et al. Biochemistry 1988, 27, 2547-2557].
View Article and Find Full Text PDFThe x-ray crystal structure of pea lectin, in complex with a methyl glycoside of the N-linked-type oligosaccharide trimannosyl core, methyl 3,6-di-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside, has been solved by molecular replacement and refined at 2.6-A resolution. The R factor is 0.
View Article and Find Full Text PDFKinetic measurements for the inhibition of porcine pancreatic elastase by 7-substituted 4-chloro-3-ethoxyisocoumarins were performed. To obtain possible explanations for the kinetic results, structures resulting from energy minimizations of inhibitor-enzyme complex structures where each inhibitor was initially positioned in 64 locations within the active site were obtained. In keeping with solution NMR studies, a positive-charged His-57 was employed.
View Article and Find Full Text PDFA step leading to the formation of the covalent complexes between porcine pancreatic elastase (PPE) and 7-[(alkylcarbamoyl)amino]-4-chloro-3-ethoxyisocoumarins (alkylHNCO-EICs) is the formation of the noncovalent Michaelis complex. No average structures are available for the Michaelis complexes of PPE with alkylHNCO-EICs. We present the results of an initial step in obtaining these structures and have determined kinetic constants as well.
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