Biomaterial Database

Guanosine and formycin triphosphates bind at non-catalytic nucleotide binding sites of CF1 ATPase and inhibit ATP hydrolysis. 1990

K J Guerrero, and L L Ehler, and P D Boyer

Department of Chemistry and Biochemistry and Molecular Biology Institute, University of California, Los Angeles 90024.

Guanosine triphosphate and formycin triphosphate (FTP) in the presence of excess Mg2+ can bind to empty non-catalytic sites of spinach chloroplast ATPase (CF1). This results in a greatly reduced capacity for ATP hydrolysis compared to the enzyme with non-catalytic sites filled with ATP. With two GTP bound at non-catalytic sites the inhibition is about 90%; with two FTP bound about 80% inhibition is obtained. Binding and release of the nucleotides from the non-catalytic sites are relatively slow processes. Exposure of CF1 with one or two empty non-catalytic sites to 5-10 microM FTP or GTP for 15 min suffices for about 50% of the maximum inhibition. Reactivation of CF1 after exposure to higher FTP or GTP concentrations requires long exposure to 2 microM EDTA. The findings show that, contrary to previous assumptions, GTP can bind tightly to non-catalytic sites of CF1. They suggest that the presence of adenine nucleotides at non-catalytic sites might be essential for high catalytic capacity of the F1 ATPases.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
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
D005573	Formycins	Pyrazolopyrimidine ribonucleosides isolated from Nocardia interforma. They are antineoplastic antibiotics with cytostatic properties.
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
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
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
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