title: Interaction of flavin mononucleotide with dimeric and tetrameric forms of muscle phosphorylase beta.
abstract: Interaction of flavin mononucleotide (FMN) with dimeric and tetrameric forms of rabbit muscle glycogen phosphorylase beta has been studied under the conditions when allosteric activator binding sites are saturated by AMP (1 mM AMP; pH 6.8; 17 degrees C). Simultaneous use of schlieren optical system and photoelectric scanning absorption optical system of analytical ultracentrifuge Spinco, model E, makes it possible to register the oligomeric state of the enzyme and calculate the degree of saturation of individual oligomeric enzyme forms by FMN. The apparent association constant for the equilibrium dimer in equilibrium with tetramer decreased with increasing FMN concentration. The microscopic dissociation constants for the complexes of dimeric and tetrameric forms of glycogen phosphorylase beta with FMN have been found to be equal to 10 and 79 microM, respectively.
authors.affiliation: AN Bach Institute of Biochemistry, USSR Academy of Sciences, Moscow.
authors.forename: N A
authors.initials: NA
authors.lastname: Chebotareva
authors.forename: B I
authors.initials: BI
authors.lastname: Kurganov
authors.forename: A E
authors.initials: AE
authors.lastname: Lyubarev
authors.forename: D R
authors.initials: DR
authors.lastname: Davydov
authors.forename: N D
authors.initials: ND
authors.lastname: Pekel
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000495:Allosteric Site; D000818:Animals; D005486:Flavin Mononucleotide / Q000378:metabolism*; D015394:Molecular Structure; D010763:Phosphorylase b / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits
chemical_list: D000249:Adenosine Monophosphate; D005486:Flavin Mononucleotide; D010763:Phosphorylase b