title: Inhibition of muscle glycogen phosphorylase b by vitamin B2 and its coenzyme forms.
abstract: Kinetic studies have demonstrated that vitamin B2 and its coenzyme forms FMN and FAD are potent inhibitors of glycogen phosphorylase b from rabbit skeletal muscle. The inhibition of the enzyme by flavins has a co-operative character (Hill coefficients exceed unity). Glycogen phosphorylase b bound to FMN or FAD does not reveal catalytic activity, whereas the enzyme bound to riboflavin retains about 16% of the initial catalytic activity.
mesh_terms: D000818:Animals; D003067:Coenzymes / Q000494:pharmacology; D005486:Flavin Mononucleotide / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006003:Glycogen / Q000096:biosynthesis; D007700:Kinetics; D009132:Muscles / Q000201:enzymology*; D010763:Phosphorylase b / Q000037:antagonists & inhibitors*; D006005:Phosphorylases / Q000037:antagonists & inhibitors*; D011817:Rabbits; D012256:Riboflavin / Q000494:pharmacology*
chemical_list: D003067:Coenzymes; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide; D006003:Glycogen; D010763:Phosphorylase b; D006005:Phosphorylases; D012256:Riboflavin