Biomaterial Database

Control of proton translocation induced by ATPase activity in chloroplasts. 1975

C Carmeli, and Y Lifshitz, and A Gepshtein

1. Proton uptake was induced by ATP in the dark following light triggering of ATPase activity in chloroplasts. The accumulated protons were released when ATPase activity was inhibited by the energy transfer inhibitor DIO-9. 2. Approximately two protons were taken up for each ATP hydrolyzed at pH 8. A drop in H+/ATP ratio was caused by uncouplers such as NH4Cl and carbonyl cyanide p-trifluoromethoxyphenylhydrazone. These uncouplers caused an increase in the rate of ATP hydrolysis without a corresponding increase in proton uptake. 3. The energy transfer inhibitor dicyclocarbodiimide inhibited both ATPase activity and the rate of proton uptake without changing the H+/ATP ratio. 4. The antibiotic valinomycin caused an increase in the rate of both proton uptake and ATP hydrolysis without altering the ratio of H+/ATP. The H+/ATP ratio varied with changes in the external pH. The results were discussed in view of the chemiosmotic theory of oxidative and photosynthetic phosphorylation.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D009570	Nitriles	Organic compounds containing the -CN radical. The concept is distinguished from CYANIDES, which denotes inorganic salts of HYDROGEN CYANIDE.	Nitrile
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D010785	Photophosphorylation	The use of light to convert ADP to ATP without the concomitant reduction of dioxygen to water as occurs during OXIDATIVE PHOSPHORYLATION in MITOCHONDRIA.	Photosynthetic Phosphorylation,Phosphorylation, Photosynthetic,Phosphorylations, Photosynthetic,Photophosphorylations,Photosynthetic Phosphorylations
D002234	Carbodiimides	Compounds with the general formula RN	Carbodiimide
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D003624	Darkness	The absence of light.	Darknesses
D006835	Hydrazones	Compounds of the general formula R:N.NR2, as resulting from the action of hydrazines with aldehydes or ketones. (Grant & Hackh's Chemical Dictionary, 5th ed)	Hydrazone
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine