Enhancement of passive proton conduction through the F/sub o/ sector in mitochondrial H/sup +/-ATPase by coupling factor B

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5325649

Huang, Y; Kantham, L; Sanadi, D R

In recent work the authors had demonstrated that passive H/sup +/ conduction in F/sub o/, derived from the bovine heart mitochondrial H/sup +/-ATPase, was blocked by Cd/sup 2 +/, which is a known inhibitor of coupling factor B activity. /sup 109/Cd bound to H/sup +/-ATPase at concentrations that inhibited P/sub i/-ATP exchange and generation of ATP-driven membrane potential co-migrated with authentic, /sup 109/Cd-labeled coupling factor B (F/sub B/) in SDS-PAGE. In order to obtain direct evidence for the participation of F/sub B/ in H/sup +/ conduction, submitochondrial particles were extensively depleted of endogenous F/sub B/ by repeated washing with ammonia-EDTA (AE). The thrice washed particle (AE-P/sub 3/), showed 8-fold stimulation of ATP-dependent reversed electron flow activity on addition of F/sub B/. In the steady state measurement of membrane potential change, monitored by the redistribution of oxonol VI, a voltage sensitive dye, the enhancement by F/sub B/ was only about 20% AE-P/sub 3/ was further depleted of F/sub 1/ by treatment with 3.5 M NaBr. The resulting AEBrP was incorporated into K/sup +/-loaded liposomes with or without supplementation of F/sub B/. Passive H/sup +/ conductance initiated on addition of valinomycin was substantially greater (100% or more) in the presence of F/sub B/, confirming earlier conclusions that F/sub B/ is component of the F/sub o/ proton channel.

• Research Organization: Boston Biomedical Research Institute, MA
• OSTI ID: 5325649
• Report Number(s): CONF-8606151-; TRN: 86-031634
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
CADMIUM
BIOLOGICAL EFFECTS
PROTEINS
BIOCHEMICAL REACTION KINETICS
ATP-ASE
CADMIUM 109
CATTLE
CELL MEMBRANES
HEART
HYDROGEN COMPOUNDS
ION EXCHANGE
MITOCHONDRIA
PROTONS
TRACER TECHNIQUES
VALINOMYCIN
ACID ANHYDRASES
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BARYONS
BETA DECAY RADIOISOTOPES
BODY
CADMIUM ISOTOPES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
DOMESTIC ANIMALS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ELEMENTS
ENZYMES
EVEN-ODD NUCLEI
FERMIONS
HADRONS
HYDROLASES
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANES
METALS
NUCLEI
NUCLEONS
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PHOSPHOHYDROLASES
RADIOISOTOPES
REACTION KINETICS
RUMINANTS
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560301* - Chemicals Metabolism & Toxicology- Cells- (-1987)
550201 - Biochemistry- Tracer Techniques