Biomaterial Database

Methanol-induced release of tightly bound adenine nucleotides from thylakoid-associated CF1. 1984

G E Anthon, and A T Jagendorf

Incubation of thylakoids in 33% methanol causes a release of the tightly bound nucleotides from CF1. This methanol effect is not a stimulation of nucleotide exchange, since no medium ATP or ADP is incorporated into CF1 during the methanol treatment. While the optimal conditions for stimulating the release of tightly bound ADP were similar to those for activating the ATPase, a direct relationship between the effects was not found. The tightly bound ADP does not represent a catalytic intermediate in this system, since (a) its rate of release is much slower than enzyme turnover, and (b) the substrate specificity for hydrolysis is different from that which promotes ADP release. A regulatory role for the tightly bound ADP in methanol-activated ATPase is also not indicated, since (a) activation of the ATPase occurs much more rapidly than ADP release, and (b) after the tightly bound ADP has been lost, high rates of ATP hydrolysis still require the presence of methanol, and (c) the small ATPase activity which persists after the removal of the methanol is not correlated with the loss of bound ADP. These results show that significant rates of ATP hydrolysis can occur with ADP still tightly bound to CF1. This argues against any model in which ADP regulates ATPase activity by binding directly to the catalytic site.

UI	MeSH Term	Description	Entries
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
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
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
D006180	Proton-Translocating ATPases	Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.	ATP Dependent Proton Translocase,ATPase, F0,ATPase, F1,Adenosinetriphosphatase F1,F(1)F(0)-ATPase,F1 ATPase,H(+)-Transporting ATP Synthase,H(+)-Transporting ATPase,H(+)ATPase Complex,Proton-Translocating ATPase,Proton-Translocating ATPase Complex,Proton-Translocating ATPase Complexes,ATPase, F(1)F(0),ATPase, F0F1,ATPase, H(+),Adenosine Triphosphatase Complex,F(0)F(1)-ATP Synthase,F-0-ATPase,F-1-ATPase,F0F1 ATPase,F1-ATPase,F1F0 ATPase Complex,H(+)-ATPase,H(+)-Transporting ATP Synthase, Acyl-Phosphate-Linked,H+ ATPase,H+ Transporting ATP Synthase,H+-Translocating ATPase,Proton-Translocating ATPase, F0 Sector,Proton-Translocating ATPase, F1 Sector,ATPase Complex, Proton-Translocating,ATPase Complexes, Proton-Translocating,ATPase, H+,ATPase, H+-Translocating,ATPase, Proton-Translocating,Complex, Adenosine Triphosphatase,Complexes, Proton-Translocating ATPase,F 0 ATPase,F 1 ATPase,F0 ATPase,H+ Translocating ATPase,Proton Translocating ATPase,Proton Translocating ATPase Complex,Proton Translocating ATPase Complexes,Proton Translocating ATPase, F0 Sector,Proton Translocating ATPase, F1 Sector,Triphosphatase Complex, Adenosine
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000227	Adenine Nucleotides		Adenine Nucleotide,Adenosine Phosphate,Adenosine Phosphates,Nucleotide, Adenine,Nucleotides, Adenine,Phosphate, Adenosine,Phosphates, Adenosine
D000432	Methanol	A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.	Alcohol, Methyl,Carbinol,Sodium Methoxide,Wood Alcohol,Alcohol, Wood,Methoxide, Sodium,Methyl Alcohol
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities