title: Escherichia coli F1-ATPase can use GTP-nonchaseable bound adenine nucleotide to synthesize ATP in dimethyl sulfoxide.
abstract: Escherichia coli F1-ATPase contained 3 mol of tightly-bound adenine nucleotide/mol enzyme. A further 3 mol could be loaded by incubation of the enzyme with ATP. The unloaded enzyme was designated as a F1[2,1] type on the basis of the ability of GTP to displace 1 mol of adenine nucleotide/mol of F1 [Kironde, F.A.S., & Cross, R.L. (1986) J. Biol. Chem. 261, 12544-12549]. The loaded enzyme was designated F1[3,3] since GTP could displace 3 of the 6 mol of bound adenine nucleotide/mol of F1. Incubation of F1[2,1], F1[2,0], and F1[3,0] with phosphate in the presence of 30% (v/v) dimethyl sulfoxide led to the synthesis of ATP from endogenous bound ADP. Hydrolysis of newly synthesized ATP occurred on transfer of the F1 from 30% (v/v) dimethyl sulfoxide to an entirely aqueous medium. Thus, synthesis and hydrolysis of ATP can occur at GTP-nonchaseable adenine nucleotide binding sites, and these sites in dimethyl sulfoxide are not necessarily equivalent to noncatalytic sites.
authors.affiliation: Department of Biochemistry, University of British Columbia, Vancouver, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Beharry
authors.forename: P D
authors.initials: PD
authors.lastname: Bragg
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000096:biosynthesis* / Q000378:metabolism; D001665:Binding Sites; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006868:Hydrolysis; D006180:Proton-Translocating ATPases / Q000378:metabolism*
chemical_list: D000227:Adenine Nucleotides; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D004121:Dimethyl Sulfoxide