Generation of energy during CO/sub 2/ fixation in acetogenic bacteria

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6281078

Ivey, D M

The F/sub 1/-ATPase from Clostridium thermoaceticum and the F/sub 1/-F/sub 0/-ATPase from C. thermoautotrophicum have been purified and characterized. The F/sub 1/ is a 370,000 M/sub r/ complex with four types of subunit with M/sub r/ values of 60,000, 55,000, 37,000, and 17,000, in a molar ratio of 3:3:1:1. Purified F/sub 1/ would rebind to stripped membranes to reconstitute DCCD-sensitive ATPase activity. Membrane vesicles and the F/sub 1/ were examined by electron microscopy. F/sub 1/-ATPase particles projecting from the vesicles have a diameter of 10 to 12 nm. The alpha and beta subunits are most likely arranged in an alternating sequence around a central mass consisting of the gamma and delta subunits. The F/sub 1/F/sub 0/-ATPase from C. thermoautotrophicum has an apparent minimum subunit composition of six non-identical polypeptides, four of which comprise F/sub 1/ and two, with M/sub r/ values of 21,000 and 12,300, of which comprise F/sub 0/. ATP hydrolysis catalyzed by the purified enzyme was inhibited approximately 50% by DCCD. Inhibition of F/sub 1/F/sub 0/ with (/sup 14/C)DCCD resulted in the labeling of the 12,300-dalton subunit of F/sub 0/. The complex has been reconstituted with phospholipids into proteoliposomes which demonstrate ATP-P/sub i/ exchange activity, FCCP-stimulated ATPase activity, and ATP-dependent proton pumping.

• Research Organization: Georgia Univ., Athens (USA)
• OSTI ID: 6281078
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ATP-ASE
BACTERIA
CARBON 14 COMPOUNDS
CARBON DIOXIDE FIXATION
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL COMPOSITION
CLOSTRIDIUM
ELECTRON MICROSCOPY
ENZYME ACTIVITY
ENZYMES
FRACTIONATION
HYDROLASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MEMBRANES
MICROORGANISMS
MICROSCOPY
PHOSPHOHYDROLASES
SEPARATION PROCESSES
TRACER TECHNIQUES