Calcium transport in vesicles energized by cytochrome oxidase

Thesis/Dissertation · Mon Jan 01 00:00:00 EST 1979

DOI:https://doi.org/10.2172/6252979· OSTI ID:6252979

Rosier, Randy N. ^[1]

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1. Univ. of Rochester, NY (United States)

Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K⁺ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K⁺ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

• Research Organization: Univ. of Rochester, NY (United States). Dept. of Radiation Biology and Biophysics
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-02-3490
• OSTI ID: 6252979
• Report Number(s): UR-3490-1549(Vols.1-2)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
60 APPLIED LIFE SCIENCES
ADP
BIOCHEMICAL REACTION KINETICS
PHOSPHORYLATION
CALCIUM
CYTOCHROME OXIDASE
OXIDATION
CYTOCHROMES
PHOSPHOLIPIDS
ANTIBIOTICS
DIFFUSION
EXPERIMENTAL DATA
GRAPHS
ION EXCHANGE
MEMBRANES
POTASSIUM IONS
PROTEINS
RESPIRATION
VALINOMYCIN
ALKALINE EARTH METALS
CHARGED PARTICLES
CHEMICAL REACTIONS
DATA
DATA FORMS
DRUGS
ELEMENTS
ENZYMES
ESTERS
INFORMATION
IONS
KINETICS
LIPIDS
METALS
NUCLEOTIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXIDASES
OXIDOREDUCTASES
PIGMENTS
REACTION KINETICS
550200* - Biochemistry