| | 1 | Author
| EgbertJ. Boekema, Günter Schmidt, Peter Gräber, JanA. Berden | Requires cookie* | | | Title
| Structure of the ATP-Synthase from Chloroplasts and Mitochondria Studied by Electron Microscopy  | | | | Abstract
| The structure of the ATP-synthase, F 0 F,, from spinach chloroplasts and beef heart mitochon-dria has been investigated by electron microscopy with negatively stained specimens. The deter-gent-solubilized ATP-synthase forms string-like structures in which the F 0 parts are aggregated. In most cases, the F, parts are arranged at alternating sides along the string. The F 0 part has an approximate cylindrical shape with heights of 8.3 and 8.9 nm and diameters of 6.2 and 6.4 nm for the chloroplast and mitochondrial enzyme, respectively. The F, parts are disk-like structures with a diameter of about 11.5 nm and a height of about 8.5 nm. The F, parts are attached to the strings, composed of F n parts, in most cases, with their smallest dimension parallel to the strings. The stalk connecting F 0 and F, has a length of 3.7 nm and 4.3 nm and a diameter of 2.7 nm and 4.3 nm for the chloroplast and mitochondrial enzyme, respectively. | | | |
Reference
| Z. Naturforsch. 43c, 219—225 (1988); received December 1 1987 | | | |
Published
| 1988 | | | |
Keywords
| ATP-Synthase, Enzyme Structure, Electron Microscopy | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/43/ZNC-1988-43c-0219.pdf | | | | Identifier
| ZNC-1988-43c-0219 | | | | Volume
| 43 | |
| 2 | Author
| G. Ünter Schmidt, PeterG. Räber | Requires cookie* | | | Title
| The Rate of ATP Hydrolysis Catalyzed by Reconstituted CF0F i-Liposomes | | | | Abstract
| The conditions for optimal rates of ATP hydrolysis catalyzed by the chloroplast ATP-synthase (A T P ase), CFoF,, after isolation and reconstitution into asolectin liposomes have been investi gated. The rate of ATP hydrolysis was m easured either after oxidation of CF0F, (by incubation with iodosobenzoate) or after reduction of CFoF, (by incubation with dithiothreitol). In both cases a rate of about 1 -2 A TP (CF0F i-s)" ' was observed under uncoupled conditions. If the pro-teoliposom es are first energized by an acid-base transition and a K"/valinomycin diffusion po ten tial, the uncoupled rate of A TP hydrolysis is about 1 -2 A TP (CFnF, -s) '1 for the oxidized enzyme and about 20 for the reduced species. This rate is about a factor 2 smaller than that observed in chloroolasts under the same conditions. | | | |
Reference
| Z. Naturforsch. 42c, 231 (1987); received O ctober 17 1986 | | | |
Published
| 1987 | | | |
Keywords
| A TP Hydrolysis, ATP Synthase, A TPase, Reconstitution, CF0F, Liposomes | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/42/ZNC-1987-42c-0231.pdf | | | | Identifier
| ZNC-1987-42c-0231 | | | | Volume
| 42 | |
|
