[Interaction of muscle glycogen phosphorylase B with flavin mononucleotide and its analogs].
The inhibition of rabbit skeletal muscle glycogen phosphorylase B by FMN and its analogues with substituents in the positions 6 and 8 has been studied. Inhibiting action of FMN is manifested in reducing the limiting rate of enzymic reaction and in increasing the half-saturation concentration of AMP. The inhibitor half-saturation values (in microM) increase in the following order: FMN (13,5), 6-bromo-FMN (27), 8 alpha-hydroxy-FMN (30), 8-dimethylamino(nor)-FMN (33), 6-(N-acetyl-L-cysteine-S-yl)-FMN (44), 6-amino-FMN (96), 8-hydroxy(nor)-FMN (109), 6-nitro-FMN (170), 8 alpha-(N-acetyl-L-cysteine-S-yl)-FMN (260). The existence of the glycogen phosphorylase B complexes with FMN or its analogues has been proved by spectrophotometry and sedimentation in analytical ultracentrifuge. FMN has been shown to hinder AMP-induced transition of dimeric form of the enzyme to tetrameric one. AMP at high concentrations has been found to inhibit glycogen phosphorylase B.
D000818:Animals; D004151:Dipeptides / Q000494:pharmacology*; D006003:Glycogen / Q000096:biosynthesis; D066298:In Vitro Techniques; D007700:Kinetics; D009132:Muscles / Q000201:enzymology*; D010763:Phosphorylase b / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006005:Phosphorylases / Q000037:antagonists & inhibitors*; D011817:Rabbits; D013379:Substrate Specificity
D004151:Dipeptides; C017330:N-formylmethionylphenylalanine; D006003:Glycogen; D010763:Phosphorylase b; D006005:Phosphorylases
Vzaimodeĭstvie myshechnoĭ glikogenfosforilazy B s flavinmononukleotidom i ego analogami.