The Proton-Translocating Pumps of Oxidative Phosphorylation

The proton conducting F0-part of bacterial ATP synthases

“…These proteinases digested subunit b eompletely, demonstrating that the polar domain of subunit b extends to the eytoplasm in E. coli, sinee everted membrane vesicles were used. With ehymotrypsin, however, a defined cleavage produet of M r 15000 was 5 observed, whieh remained firmly bound to the membrane, as treatment with high salt, urea or guanidine hydroehloride failed to remove this fragment from the membrane. By proteinehemieal analyses it was shown that ehymotrypsin did not cleave at the primary cleavage sites phenylalanine, tyrosine, tryptophan or methionine, whieh are all loeated in the hydrophobie N-terminal segment of the subunit b.…”

“…Lane A shows separated Fjl'O-, and lane B, separated Fj-depleted membranes. The proteinase concentrations, increase in the sampIes from left to right for V8 Clanes 1-3), chymotrypsin [4][5][6], trypsin [7][8][9] and subtilisin [10][11][12]. The star indicates the digestion product obtained with chymotrypsin.…”

“…Several recent reviews covered the genetics of the ATP synthase [1,2], the nucleotide sequence of the ATP synthase genes of E. eoli (Walker, J.E., Saraste, M. and Gay, NJ., unpublished results), the proton-A TPase from bacteria and mitochondria [4], the structural basis of proton-translocating protein function [5], and the structure and genetics of the proteolipid subunit of the ATP synthase [6]. This review tries to collect new proteinchemical data on F o and to combine them with genetical and functional data in order to give the present-day knowledge on the structure-function relationships in this proton conductor.…”

ATP‐synthetase complex (F1F0) from Escherichia coli

“…The ATP synthetase plays an important role in bacterial energy transduction [ 1 ]. The enzyme is composed of two entities: the F~ part is a peripheric membrane protein that catalyzes the hydrolysis of ATP, whereas the Fo part is involved in H ÷ translocation across the cytoplasmic membrane.…”

Studies on the Mechanism of Action of Triphenyltin on Proton Conduction by the H+-ATPase of Mitochondria

“…FO preparations from different sources consist of a variable number of protein subunits [I 11. The use of DCCD, a specific reagent for glutamic and aspartic residues [I21 which inhibits proton conduction by Fo [1,2,6], has shown that a 7000-8000 proteolipid subunit of Fo, bearing a glutamic [13] or aspartic residue [I41 specifically attacked by DCCD [15], is directly involved in proton translocation [l, 21. Modification with phenylglyoxal of arginine residues and of tyrosine with tetranitromethane results in depression of the proton conductivity of FO of the thermophilic bacteria PS3 [16,17] and mitochondria [S, 91.…”