[High molecular weight forms of GTP-binding regulatory proteins from the bovine cerebellum].
A new form of a low Km GTPase belonging to the family of regulatory GTP-binding G-proteins has been identified in bovine cerebellum. The molecular weight of this G-protein is several times as high as that of other G-proteins known to be alpha beta gamma heterotrimers: i. e., Gs, Gi, Go, transducin and a new G-protein which had recently been isolated in our laboratory from bovine cerebellum. The high molecular weight G-protein is stable against dissociation; its molecular mass does not change after treatment with DTT, colchicine and NaF. Using antibodies against the alpha-subunit of the formerly isolated cerebellar G-protein and the transducin beta-subunit, it was demonstrated that the both immunoreactive subunits are present in the high molecular weight G-protein. The two forms of the cerebellar G-proteins, i. e., "high" and "low molecular weight" ones, differ drastically in terms of the Mg2+ effect on their GTPase activity. Whereas at submicromolar concentrations of Mg2+ the GTPase activity of the former is virtually absent, the GTPase activity of the latter is more elevated in the presence of EDTA than in the presence of Mg2+.
Voeĭkov
V L
VL
Pronin
A N
AN
Slepak
V Z
VZ
Chestukhin
A N
AN
Shlenskiĭ
A B
AB
D000818:Animals; D002417:Cattle; D002531:Cerebellum / Q000032:analysis* / Q000201:enzymology; D002850:Chromatography, Gel; D020558:GTP Phosphohydrolases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D019204:GTP-Binding Proteins / Q000302:isolation & purification*; D066298:In Vitro Techniques; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008565:Membrane Proteins / Q000302:isolation & purification*; D008970:Molecular Weight; D010744:Phosphoric Monoester Hydrolases / Q000302:isolation & purification*; D015293:Transducin
D008565:Membrane Proteins; D010744:Phosphoric Monoester Hydrolases; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D015293:Transducin; D008274:Magnesium
Vysokomolekuliarnye formy GTP-sviazyvaiushchikh reguliatornykh belkov iz mozzhechka byka.