title: Butyrylcholinesterase-Mediated enhancement of the enzymatic activity of trypsin.
abstract: 1. Acetylcholinesterase (AChE, EC 3.1.1.7) and butyrylcholinesterase (BuChE, EC 3.1.1.8) are enzymes that catalyze the hydrolysis of esters of choline. 2. Both AChE and BuChE have been shown to copurify with peptidases. 3. BuChE has also been shown to copurify with other proteins such as transferrin, with which it forms a stable complex. In addition, BuChE is found in association with beta-amyloid protein in Alzheimer brain tissues. 4. Since BuChE copurifies with peptidases, we hypothesized that BuChE interacts with these enzymes and that this association had an influence on their catalytic activities. One of the peptidases that copurifies with cholinesterases has specificity similar to trypsin, hence, this enzyme was used as a model to test this hypothesis. 5. Purified BuChE causes a concentration-dependent enhancement of the catalytic activity of trypsin while trypsin does not influence the catalytic activity of BuChE. 6. We suggest that, in addition to its esterase activity, BuChE may assume a regulatory role by interacting with other proteins.
authors.affiliation: Department of Medicine, Halifax, Nova Scotia, Canada. sdarvesh@is.dal.ca
authors.forename: S
authors.initials: S
authors.lastname: Darvesh
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: S
authors.initials: S
authors.lastname: Roberts
authors.forename: R
authors.initials: R
authors.lastname: Walsh
authors.forename: E
authors.initials: E
authors.lastname: Martin
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000544:Alzheimer Disease / Q000201:enzymology; D001586:Benzoylarginine Nitroanilide / Q000494:pharmacology; D002091:Butyrylcholinesterase / Q000378:metabolism / Q000494:pharmacology*; D002863:Chromogenic Compounds / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D006868:Hydrolysis; D014357:Trypsin / Q000378:metabolism*
chemical_list: D002863:Chromogenic Compounds; D001586:Benzoylarginine Nitroanilide; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D014357:Trypsin