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Titolo:
INTERACTION OF MITOCHONDRIAL F1-ATPASE WITH TRINITROPHENYL DERIVATIVES OF ATP - PHOTOAFFINITY-LABELING OF BINDING-SITES WITH 2-AZIDO-2',3'-O-(4,6-TRINITROPHENYL)ADENOSINE 5'-TRIPHOSPHATE
Autore:
MURATALIEV MB;
Indirizzi:
UNIV ARIZONA,DEPT ENTOMOL,FORBES 410 TUCSON AZ 85721 UNIV CALIF LOS ANGELES,INST MOLEC BIOL LOS ANGELES CA 90024 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM LOS ANGELES CA 90024
Titolo Testata:
European journal of biochemistry
fascicolo: 2, volume: 232, anno: 1995,
pagine: 578 - 585
SICI:
0014-2956(1995)232:2<578:IOMFWT>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
ADENINE-NUCLEOTIDE BINDING; ADENOSINE-TRIPHOSPHATASE; CATALYTIC SITE; CHLOROPLAST F1-ATPASE; NONCATALYTIC SITES; BETA-SUBUNIT; MECHANISM; HYDROLYSIS; ADP; COOPERATIVITY;
Keywords:
F1 ADENOSINE TRIPHOSPHATASE; ATP SYNTHASE; PHOTOAFFINITY LABELING; ATP ANALOGS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
33
Recensione:
Indirizzi per estratti:
Citazione:
M.B. Murataliev, "INTERACTION OF MITOCHONDRIAL F1-ATPASE WITH TRINITROPHENYL DERIVATIVES OF ATP - PHOTOAFFINITY-LABELING OF BINDING-SITES WITH 2-AZIDO-2',3'-O-(4,6-TRINITROPHENYL)ADENOSINE 5'-TRIPHOSPHATE", European journal of biochemistry, 232(2), 1995, pp. 578-585

Abstract

It was shown recently that ATP present at near saturating concentrations did not prevent binding and hydrolysis of submicromolar concentration of trinitrophenyl adenosine triphosphate (Tnp-ATP) by F-1-ATPase [Murataliev, M. B. & Boyer, P. O. (1994) J. Biol. Chem. 269, 15431-15439]. To explore F-1-ATPase binding sites that bind Tnp-ATP a new photoreactive analog of ATP, 2-azido-trinitrophenyl adenosine triphosphate (2-N-3-Tnp-ATP) has been synthesized and used for photoaffinity labeling of mitochondrial F-1-ATPase. The analog shares many properties of the parent non-azido Tnp-ATP as shown from spectral characteristics, binding with F-1-ATPase, and kinetic and inhibition studies, 500 mu M ATPdoes not prevent binding and hydrolysis of low concentrations of 2-N-3-Tnp-ATP by F-1-ATPase. Photoirradiation of the enzyme-analog complexformed under such conditions results in the labeling of the catalytic-site peptide. This shows that in the presence of near saturating ATP,Tnp-ATP can enter the catalytic cycle and inhibit ATP hydrolysis by initial binding at a third catalytic site. The results give strong evidence that only two catalytic sites need to have bound substrate for near maximal turnover rate, and that three catalytic sites of F-1-ATPaseparticipate equally in catalysis. When F-1-ATPase binds substoichiometric 2-N-3-Tnp-ATP in the presence of Mg2+, illumination of the inactive complex formed results in the covalent labeling of a catalytic site. This shows that F-1-ATPase forms similar inactive complexes when ADPor Tnp-ADP is bound at a catalytic site in the presence of Mg2+. Exposure of the nucleotide-depleted F-1-ATPase to 20 mu M 2-N-3-Tnp-ATP followed by a short incubation with excess of Tnp-ATP results in binding, and, upon illumination, in a covalent labeling of a non-catalytic-sire peptide.

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Documento generato il 01/10/20 alle ore 15:05:36