Biomaterial Database

The effect of phosphate on light-induced exchange of ADP at the tight nucleotide binding site of CF1. 1980

V Shoshan, and H Strotmann

The effects of phosphate on the energy-dependent exchange of the tightly bound adenine nucleotides in chloroplast thylakoids has been studied. 1. Phosphate was found to have a dual effect on ADP binding; at low light intensities Pi enhanced the rate of binding and the total amount of tightly bound ADP, while at saturating light intensities, it decreased the level of bound nucleotides. Half-maximal stimulation or inhibition of ADP binding occurred at about 30 microM phosphate. 2. Phosphate inhibition of ADP binding at saturating light intensities is prevented in the presence of an ADP-regenerating system. Pi had no effect on the amount of ATP bound to chloroplast coupling factor 1 (CF1), which was lower than the amount of ADP bound. 3. Arsenate acted similarly to phosphate at low light intensities but not at saturating light intensities. 4. At low light intensities the interaction of phosphate with the membrane-bound CF1 increased the binding affinity for ADP about 8-fold. 5. Kinetic analysis of the ADP binding showed that phosphate increased the rate constant for ADP binding to the adenine nucleotide-depleted form of CF1.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
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
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
D006593	Hexokinase	An enzyme that catalyzes the conversion of ATP and a D-hexose to ADP and a D-hexose 6-phosphate. D-Glucose, D-mannose, D-fructose, sorbitol, and D-glucosamine can act as acceptors; ITP and dATP can act as donors. The liver isoenzyme has sometimes been called glucokinase. (From Enzyme Nomenclature, 1992) EC 2.7.1.1.	Hexokinase A,Hexokinase D,Hexokinase II
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D001149	Arsenates	Inorganic or organic salts and esters of arsenic acid.
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining