Biomaterial Database

Inactivation of arginine esterase E-I of Bitis gabonica venom by irreversible inhibitors including a water-soluble carbodiimide, a chloromethyl ketone and isatoic anhydride. 1991

P S Gravett, and C C Viljoen, and M M Oosthuizen

Health Chemical Laboratory, Department of National Health and Population Development, Pretoria, Republic of South Africa.

1. Esterase E-I from Bitis gabonica was inactivated with irreversible inhibitors which included studies with a water-soluble carbodiimide, an affinity labelling peptide and a mechanism-based inactivator. 2. The reaction with 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide was biphasic and the dominant part followed saturation kinetics. At pH 5.5 a rate constant of 0.4 min-1 for inactive enzyme formation was calculated and a dissociation constant (Ki) of 0.2 M for the enzyme-inhibitor complex. 3. Inactivation with D-Phe-Pro-Arg-chloromethyl ketone indicated a two-step mechanism, for which the reaction parameters at pH 8.0 were determined. The Ki value was 0.2 microM and the inactivation rate was 2.5 min-1. 4. With isatoic anhydride pseudo-first-order kinetics was observed. At pH 8.0 a rate constant of 0.9 min-1 and a Ki of 2.0 mM were obtained. The inactivation of the enzyme was found to be governed by a group in the enzyme showing a pK value of 7.3.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010078	Oxazines	Six-membered heterocycles containing an oxygen and a nitrogen.
D002265	Carboxylic Ester Hydrolases	Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.	Carboxylesterases,Ester Hydrolases, Carboxylic,Hydrolases, Carboxylic Ester
D005022	Ethyldimethylaminopropyl Carbodiimide	Carbodiimide cross-linking reagent.	1-Ethyl-3-(3-Dimethylaminopropyl)Carbodiimide,3-(3-Dimethylaminopropyl)-1-Ethylcarbodiimide,EDAP-Carbodiimide,Carbodiimide, Ethyldimethylaminopropyl,EDAP Carbodiimide
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000590	Amino Acid Chloromethyl Ketones	Inhibitors of SERINE ENDOPEPTIDASES and sulfhydryl group-containing enzymes. They act as alkylating agents and are known to interfere in the translation process.	Peptide Chloromethyl Ketones,Chloromethyl Ketones, Peptide,Ketones, Peptide Chloromethyl
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001120	Arginine	An essential amino acid that is physiologically active in the L-form.	Arginine Hydrochloride,Arginine, L-Isomer,DL-Arginine Acetate, Monohydrate,L-Arginine,Arginine, L Isomer,DL Arginine Acetate, Monohydrate,Hydrochloride, Arginine,L Arginine,L-Isomer Arginine,Monohydrate DL-Arginine Acetate
D012995	Solubility	The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Solubilities