Biomaterial Database

Leaving group effects in butyrylcholinesterase reaction with organophosphorus inhibitors. 1978

U Langel, and J Järv

The kinetic constants k2, KQ and the second-order rate constant ki of butyrylcholinesterase (acylcholine acylhydrolase, EC 3.1.1.8) inhibition by organophosphorus compounds (C2H5O)2P(O)SX, with both ionic and non-ionic substituents X, were determined at 25 degrees C and pH 7.5 in 0.15 M KCl. The data were analysed in terms of structure-activity relationships and the roles of the leaving group inductive effect and hydrophobicity in the enzyme specificity were established. This made possible calculations of the actual contribution of the substituent ionic charge in the effectivenes of butyrylcholinesterase action. On the basis of the structure-activity relationships for butyrylcholinesterase and acetylcholinesterase the specificities of the enzymes are compared and some common features are discussed.

UI	MeSH Term	Description	Entries
D009946	Organothiophosphorus Compounds	Compounds containing carbon-phosphorus bonds in which the phosphorus component is also bonded to one or more sulfur atoms. Many of these compounds function as CHOLINERGIC AGENTS and as INSECTICIDES.	Compounds, Organothiophosphorus
D002091	Butyrylcholinesterase	An aspect of cholinesterase (EC 3.1.1.8).	Pseudocholinesterase,Benzoylcholinesterase,Butyrylthiocholinesterase
D002627	Chemistry, Physical	The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.	Physical Chemistry,Chemistries, Physical,Physical Chemistries
D002800	Cholinesterase Inhibitors	Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.	Acetylcholinesterase Inhibitor,Acetylcholinesterase Inhibitors,Anti-Cholinesterase,Anticholinesterase,Anticholinesterase Agent,Anticholinesterase Agents,Anticholinesterase Drug,Cholinesterase Inhibitor,Anti-Cholinesterases,Anticholinesterase Drugs,Anticholinesterases,Cholinesterase Inhibitors, Irreversible,Cholinesterase Inhibitors, Reversible,Agent, Anticholinesterase,Agents, Anticholinesterase,Anti Cholinesterase,Anti Cholinesterases,Drug, Anticholinesterase,Drugs, Anticholinesterase,Inhibitor, Acetylcholinesterase,Inhibitor, Cholinesterase,Inhibitors, Acetylcholinesterase,Inhibitors, Cholinesterase,Inhibitors, Irreversible Cholinesterase,Inhibitors, Reversible Cholinesterase,Irreversible Cholinesterase Inhibitors,Reversible Cholinesterase Inhibitors
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D055598	Chemical Phenomena	The composition, structure, conformation, and properties of atoms and molecules, and their reaction and interaction processes.	Chemical Concepts,Chemical Processes,Physical Chemistry Concepts,Physical Chemistry Processes,Physicochemical Concepts,Physicochemical Phenomena,Physicochemical Processes,Chemical Phenomenon,Chemical Process,Physical Chemistry Phenomena,Physical Chemistry Process,Physicochemical Phenomenon,Physicochemical Process,Chemical Concept,Chemistry Process, Physical,Chemistry Processes, Physical,Concept, Chemical,Concept, Physical Chemistry,Concept, Physicochemical,Concepts, Chemical,Concepts, Physical Chemistry,Concepts, Physicochemical,Phenomena, Chemical,Phenomena, Physical Chemistry,Phenomena, Physicochemical,Phenomenon, Chemical,Phenomenon, Physicochemical,Physical Chemistry Concept,Physicochemical Concept,Process, Chemical,Process, Physical Chemistry,Process, Physicochemical,Processes, Chemical,Processes, Physical Chemistry,Processes, Physicochemical