Biomaterial Database

Geometric isomers of covalently labeled mitochondrial F1-adenosinetriphosphatase with different properties. 1986

J H Wang, and V Joshi, and J C Wu

Two geometric isomers of covalently labeled F1-adenosinetriphosphatase (F1-ATPase) have been prepared by reaction with 7-chloro-4-nitro-2,1,3-benzoxadiazole (NBD-Cl): a directly labeled product denoted by O-beta'-NBD-F1 and an indirectly prepared product denoted by 0-beta'-NBD-F1. The normal isomer O-beta'-NBD-F1 is highly inhibited, and its label can be removed by 20 microM N-acetyl-L-cysteine (AC) at the expected rate with dr/dn approximately equal to -1, where n is the molar ratio of the label to F1 and r is the ratio of the ATPase activity of the labeled enzyme to that of the unlabeled control enzyme. But O-beta"-NBD-F1 is almost fully active, and its label can be removed by 20 microM AC at much slower rates with dr/dn approximately equal to 0. Cleavage of either isomer with pepsin and subsequent amino acid analysis of the isolated radioactive polypeptides show that the label is attached to Tyr-beta 311 in both isomers. At pH 9 the label in O-beta'-NBD-F1 spontaneously transfers from Tyr-beta 311 to the presumably nearby Lys-beta 162 in the dark with a half-time of 1/2 h, but the label in O-beta"-NBD-F1 does not transfer under the same conditions. The existence of geometric isomers of O-NBD-F1 with contrastingly different properties invalidates models for F1 with three equivalent beta subunits but is consistent with the model based on one principal catalytic beta' subunit and two auxiliary beta" subunits. A possible mechanism for promoting the catalytic efficiency of beta' through protein conformation change induced by ATP and/or ADP is suggested.

UI	MeSH Term	Description	Entries
D007536	Isomerism	The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Isomerisms
D008929	Mitochondria, Heart	The mitochondria of the myocardium.	Heart Mitochondria,Myocardial Mitochondria,Mitochondrion, Heart,Heart Mitochondrion,Mitochondria, Myocardial
D009327	4-Chloro-7-nitrobenzofurazan	A benzofuran derivative used as a protein reagent since the terminal N-NBD-protein conjugate possesses interesting fluorescence and spectral properties. It has also been used as a covalent inhibitor of both beef heart mitochondrial ATPase and bacterial ATPase.	Chloronitrobenzoxadiazole,NBD Chloride,7-Chloro-4-nitrobenzofurazan,NBF-Cl,Nitrobenzoxadiazole Chloride,4 Chloro 7 nitrobenzofurazan,7 Chloro 4 nitrobenzofurazan,Chloride, NBD,Chloride, Nitrobenzoxadiazole,NBF Cl
D010069	Oxadiazoles	Compounds containing five-membered heteroaromatic rings containing two carbons, two nitrogens, and one oxygen atom which exist in various regioisomeric forms.	Oxadiazole
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
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
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence