title: A capillary zone electrophoretic method for the study of formation of a covalent conjugate between microcystin LR and protein phosphatase 2A.
abstract: The study of conjugate formation between microcystin (MCYST)-LR and protein phosphatase (PP) 2A, which was isolated from bovine kidney and mouse brain, was achieved by using a highly efficient capillary zone electrophoretic (CZE) separation method. The MCYST-LR-PP2A conjugate (from bovine kidney) was resolved from its precursor after just 15 min of incubation. Moreover, the migration time, and, hence, the total analysis time, was less than 5 min. While the present findings of the time lag between conjugate formation and full inhibition are not novel, the CZE method does provide an alternative tool to HPLC with a higher separation efficiency to yield data for kinetic and mechanistic studies of the enzyme-toxin interaction. The CZE data reported here were found not to be adequately described by a first-order kinetic model. Moreover, the CZE method, which involves the use of a low ionic strength aqueous buffer, does not suffer from the drawback of the use of denaturing organic solvents such as those used in HPLC.
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, SAR, China.
authors.forename: S
authors.initials: S
authors.lastname: Hu
authors.forename: P C
authors.initials: PC
authors.lastname: Li
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D019075:Electrophoresis, Capillary; D007668:Kidney / Q000737:chemistry; D051379:Mice; D052998:Microcystins; D010456:Peptides, Cyclic / Q000737:chemistry*; D010749:Phosphoprotein Phosphatases / Q000737:chemistry*; D054648:Protein Phosphatase 2; D014118:Toxins, Biological / Q000737:chemistry*
chemical_list: D052998:Microcystins; D010456:Peptides, Cyclic; D014118:Toxins, Biological; C078588:microcystin; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2