title: Use of capillary electrophoresis to evaluate protective effects of methylglyoxal scavengers on the activity of creatine kinase.
abstract: Methylglyoxal (MGO) is a highly reactive alpha-oxoaldehyde formed endogenously in numerous enzymatic and nonenzymatic reactions. The reactions between MGO and various amino residues in proteins not only result in inactivation of enzymes, but also lead to the formation of different detrimental advanced glycation endproducts (AGEs). Recently, it was reported that creatine kinase (CK, EC 2.7.3.2) activity could be reduced or even lost under incubation with MGO in vitro. In this study, an efficient CE analytical method was developed for the evaluation of CK activity. Based on this CE method, the inhibitory effect of MGO on CK activity was confirmed. Several MGO scavengers such as aminoguanidine (AG) and some thiols showed obvious protective effects on CK activity against MGO. Furthermore, tiopronin (TP), a hepatoprotective drug, was found for the first time to counteract MGO-induced inhibition of CK activity in CK reaction. Meanwhile, TP also retained adenosine diphosphate (ADP) generation level in plasma treated with MGO, which implies that this drug may have potential protective effect on other enzymes which are associated with adenine nucleotide metabolism. Besides, the established CE approach can be utilized as a model for screening effective MGO scavengers by monitoring CK-catalyzed conversion between adenosine triphosphate and ADP.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong, PR hina.
authors.forename: Jinyu
authors.initials: J
authors.lastname: Ma
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Peng
authors.forename: Ka-Wing
authors.initials: KW
authors.lastname: Cheng
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Dajin
authors.initials: D
authors.lastname: Yang
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Mingfu
authors.initials: M
authors.lastname: Wang
mesh_terms: D003402:Creatine Kinase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods; D004789:Enzyme Activation / Q000187:drug effects; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D011765:Pyruvaldehyde / Q000032:analysis* / Q000494:pharmacology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D008625:Tiopronin / Q000737:chemistry / Q000494:pharmacology
chemical_list: D016166:Free Radical Scavengers; D011765:Pyruvaldehyde; D008625:Tiopronin; D003402:Creatine Kinase