scholarly journals Adenosine triphosphate-evoked catecholamine release in chromatin granules. Osmotic lysis as a consequence of proton translocation

1976 ◽  
Vol 158 (3) ◽  
pp. 583-588 ◽  
Author(s):  
R P Casey ◽  
D Njus ◽  
G K Radda ◽  
P A Sehr
Keyword(s):  
Oxidative Phosphorylation ◽  
Adenosine Triphosphate ◽  
Adenosine Triphosphatase ◽  
Proton Translocation ◽  
Catecholamine Release ◽  
Chromaffin Granules ◽  
Release Process ◽  
Media Release ◽  
Osmotic Lysis ◽  
Permeant Anion

Chromaffin granules suspended in C1-containing media release catecholamine and protein when ATP is added. This phenomenon is inhibited in hyperosmotic media and in the presence of uncouplers of oxidative phosphorylation. Release requires a permeant anion in the medium, but is independent of the cation. The release process appears to be driven by an inwardly directed proton-translocating adenosine triphosphatase. The resulting proton-anion influx causes osmotic lysis of the chromaffin granules.

scholarly journals Studies of energy-linked reactions. Net synthesis of adenosine triphosphate by isolated adenosine triphosphate synthase preparations: a role for lipoic acid and unsaturated fatty acids

1976 ◽  
Vol 160 (3) ◽  
pp. 809-812 ◽  
Author(s):  
D E Griffiths
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Oxidative Phosphorylation ◽  
Adenosine Triphosphate ◽  
Atp Synthase ◽  
Lipoic Acid ◽  
Adenosine Triphosphatase ◽  
Unsaturated Fatty Acids ◽  
Atp Synthesis ◽  
Substrate Level

ATP synthase preparations [complex V, proton-translocatin ATPase (adenosine triphosphatase) and oligomycin-sensitive ATPase] contain stoicheiometric amounts of lipoic acid residues (up to 6mol of lipoic acid/mol of ATPase complex) and catalyse net ATP synthesis in an uncoupler-and oligomycin-sensitive reaction utilizing dihydrolipoate, oleoyl-CoA and oleic acid, or in a reaction utilizing oleoyl-S-lipoate. The terminal reactions of oxidative phosphorylation are thus analogous to those of substrate-level phosphorylation.

scholarly journals The microbiol metabolism of C1 compounds. Oxidative phosphorylation in membrane preparations of Pseudomonas AM1

1979 ◽  
Vol 178 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Alexander I. Netrusov ◽  
Christopher Anthony
Keyword(s):  
Oxidative Phosphorylation ◽  
Adenosine Triphosphatase ◽  
Proton Translocation ◽  
Atp Synthesis ◽  
Membrane Vesicles ◽  
Antimycin A ◽  
O2 Consumption ◽  
Whole Cells ◽  
Carbonyl Cyanide ◽  
Cytochromes C

A method is described for preparation of membrane vesicles (diameter 80nm) capable of respiration-linked ATP synthesis. Vesicles prepared from succinate-grown bacteria oxidized NADH, succinate and ascorbate plus NNN′N′-tetramethylphenylenediamine; vesicles prepared from methanol-grown bacteria also oxidized methanol and formaldehyde, but they were otherwise identical. The uncoupling agent carbonyl cyanide chlorophenylhydrazone and the adenosine triphosphatase inhibitor dicyclohexylcarbodi-imide both inhibited ATP synthesis, whereas they had no effect on the rate of respiration. Rotenone inhibited ATP synthesis and respiration with NADH as substrate; antimycin A inhibited with succinate as substrate, and cyanide inhibited with all substrates. P/O ratios were usually 0.7–1.3 with NADH, 0.6–1.0 with succinate and 0.2–0.6 with reduced NNN′N′-tetramethylphenylenediamine or methanol as respiratory substrate. When 2,6-dichlorophenol-indophenol was used as an alternative electron acceptor to O2 (NADH as donor) the P/2e ratio was 1.65. Although these P/O ratios are minimum values, because they do not take into account unknown amounts of uncoupled O2 consumption, they are consistent with previous proposals [O'Keeffe & Anthony (1978) Biochem, J.170, 561–567] based on measurements of proton translocation in whole cells. The results also confirm that methanol dehydrogenase and cytochromes c and a/a3 are arranged so that the first step in methanol oxidation is coupled to synthesis of ATP.

scholarly journals Partial diploids of Escherichia coli carrying normal and mutant alleles affecting oxidative phosphorylation

1977 ◽  
Vol 162 (3) ◽  
pp. 665-670 ◽  
Author(s):  
F Gibson ◽  
G B Cox ◽  
J A Downie ◽  
J Radik
Keyword(s):  
Escherichia Coli ◽  
Fluorescence Quenching ◽  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Growth Yields ◽  
Normal Allele ◽  
Adenosine Triphosphatase Activity

A plasmid was isolated which included the region of the Escherichia coli chromosome carrying the known genes concerned with oxidative phosphorylation (unc genes). This plasmid was used to prepare partial diploids carrying normal unc alleles on the episome and one of the three mutant alleles (unc A401, uncB402 or unc-405) on the chromosome. These strains were compared with segregants from which the plasmid had been lost. Dominance of either normal ormutant unc alleles was determined by growth on succinate, growth yields on glucose, Mg-ATPase (Mg2+-stimulated adenosine triphosphatase) activity, atebrin-fluorescence quenching, ATP-dependent transhydrogenase activity and oxidative phosphorylation. In all the above tests, dominance of the normal allele was observed. However, in membranes from the diploid strains which carried a normal allele and either of the mutant alleles affecting Mg-ATPase activity (uncA401 or unc-405), the energy-linked functions were only partially restored.

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