Catalytic activity and arrangement of subunit polypeptides in rat liver cytochrome c oxidase as studied by proteolysis |
| |
Authors: | Haruko Nagasawa-Fujimori Toru Nagasawa Peter C. Heinrich |
| |
Affiliation: | Department of Biochemistry, University of Freiburg, 7800 Freiburg im Breisgau F.R.G. |
| |
Abstract: | Cytochrome c oxidase from rat liver was incubated with various proteinases of different specificities and the enzymic activity was measured after various incubation times. A loss of catalytic activity was found after digestion with proteinase K, aminopeptidase M and a mitochondrial proteinase from rat liver. In each case the decrease in enzymic activity was compared with the changes in intensities of the polypeptide pattern obtained after sodium dodecyl sulfate polyacrylamide gel electrophoresis. The susceptibilities of the subunit polypeptides of the soluble cytochrome c oxidase to proteinases were very different. Whereas subunit I was most susceptible, subunits V–VII were rather resistant to degradation. From the relative inaccessibility of subunits V–VII to proteinases it is likely that these polypeptides are buried in the interior of the enzyme complex. |
| |
Keywords: | Cytochrome c oxidase Proteinase Enzyme topography (Rat liver mitochondria) SDS sodium dodecyl sulfate TLCK 1-chloro-3-tosylamido-7-amino-L-2-heptanone TPCK L-1-tosylamido-2-phenylethyl chloromethyl ketone Hepes |
本文献已被 ScienceDirect 等数据库收录! |