title: [Interaction of rabbit skeletal muscle glycogen synthase I with substrate analogs--oxo-UDP hydrazones].
abstract: Inhibition of rabbit skeletal muscle glycogen synthase I was studied by using several synthetic substrate analogs: dansylhydrazone of oxo-UDP, 3-hydroxy-2-naphthoylhydrazone of oxo-UDP, salicyloylhydrazone of oxo-UDP, 1-oxyl-2,2,5,5-tetramethylpyrrolidine-3-carbonylhydrazone of oxo-UDP, N'-(dansyl)hydrazinocarbonylhydrazone of oxo-UDP and N'-(fluorenylidene-9)-hydrazinocarbonylhydrazone of oxo-UDP. All these compounds (with the exception of the nitroxyl-containing hydrazone) were characterized by a nonlinear dependence of the reverse reaction rate on the analog concentration in Dixon coordinates. The parabolic type of inhibition was due to the fact that the analogs tested except for the nitroxyl-containing hydrazone were able to interact both with the active center of the enzyme and with the FMN-binding site. The inhibition constants for oxo-UDP hydrazones were calculated for the both centers; their comparison revealed that the affinity of the analogs for the FMN-binding site increased with an increase in the radical hydrophobicity. These data suggest that the site with a high binding affinity for FMN is hydrophobic in nature. Apparently, isoalloxasine-like compounds display the highest affinity for this site.
authors.forename: G A
authors.initials: GA
authors.lastname: Solov'eva
authors.forename: L A
authors.initials: LA
authors.lastname: Baranova
authors.forename: S Iu
authors.initials: SIu
authors.lastname: Sundukov
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Khropov
mesh_terms: D000818:Animals; D001665:Binding Sites; D006006:Glycogen Synthase / Q000037:antagonists & inhibitors*; D006835:Hydrazones / Q000737:chemistry / Q000494:pharmacology*; D009132:Muscles / Q000201:enzymology*; D011817:Rabbits; D013379:Substrate Specificity; D014530:Uridine Diphosphate / Q000737:chemistry / Q000494:pharmacology*; D014532:Uridine Diphosphate Glucose / Q000378:metabolism / Q000494:pharmacology
chemical_list: D006835:Hydrazones; D014530:Uridine Diphosphate; D006006:Glycogen Synthase; D014532:Uridine Diphosphate Glucose
vernacular_title: Vzaimodeĭstvie glikogensintazy I skeletnykh myshts krolika s analogamisubstrata--gidrazonami okso-UDP.