title: Effect of crowding and chaperones on self-association, aggregation and reconstitution of apophosphorylase b.
abstract: It was shown that the rate of reconstruction of muscle glycogen phosphorylase b (Phb) from apoenzyme and pyridoxal 5'-phosphate decreased under crowding conditions. The effect of crowding was counteracted by chaperones (α-crystallin and proline). Sedimentation analysis shows that crowding stimulates the formation of high-molecular-weight associates at 25 °C, whereas chaperones stabilize small oligomers. The study of the kinetics of apoPhb aggregation at 37 °C showed that the anti-aggregation activity of chaperones decreased under crowding conditions. When studying the sedimentation behavior of the mixture of apoPhb and α-crystallin, the complexes between unfolded apoPhb and dissociated forms of α-crystallin were observed. It is assumed that these complexes are responsible for realization of the chaperone-like activity of α-crystallin under crowding conditions.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia. chebotareva@inbi.ras.ru
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Chebotareva
authors.forename: Tatyana B
authors.initials: TB
authors.lastname: Eronina
authors.forename: Svetlana G
authors.initials: SG
authors.lastname: Roman
authors.forename: Nikolay B
authors.initials: NB
authors.lastname: Poliansky
authors.forename: Konstantin O
authors.initials: KO
authors.lastname: Muranov
authors.forename: Boris I
authors.initials: BI
authors.lastname: Kurganov
mesh_terms: D000818:Animals; D007700:Kinetics; D018832:Molecular Chaperones / Q000378:metabolism*; D010763:Phosphorylase b / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011392:Proline / Q000494:pharmacology; D011732:Pyridoxal Phosphate; D011817:Rabbits; D013696:Temperature; D038201:alpha-Crystallins / Q000494:pharmacology
chemical_list: D018832:Molecular Chaperones; D038201:alpha-Crystallins; D011732:Pyridoxal Phosphate; D011392:Proline; D010763:Phosphorylase b
keywords: Aggregation; Crowding; Muscle glycogen phosphorylase b; Reconstruction of holoenzyme; Self-association