The mechanism of protein translocation into mitochondria has been investigated by studying properties of precursor proteins destined for the mitochondrial matrix. Characterization of the amphiphilic properties of the signal sequence for pre-ornithine carbamyltransferase has led to the conclusion that precursors can not translocate across the inner membrane via a lipid route alone (i.e. in the absence of proteins). A correlation was established between the rate of precursor import and the degree of hydrophobicity of a short region in the presequence, suggesting that precursor binding to the two-dimensional phospholipid surface of the outer membrane may enhance the rate of diffusion to the translocation apparatus. / The conformations of the mature portions of two hybrid proteins, pOCAT and pODHFR, were examined at various steps on the import pathway. The bulk population of these precursors remained in a near-native conformation prior to precursor engagement of the import apparatus. Unfolded polypeptide translocation intermediates, the formation of which requires ATP, an intact signal sequence, and a protease-sensitive component of the outer mitochondrial membrane, have been detected in association with submitochondrial fractions containing sites of contact between the inner and outer mitochondrial membranes.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.74254 |
| Date | January 1989 |
| Creators | Skerjanc, Ilona S. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biochemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001068584, proquestno: AAINN63400, Theses scanned by UMI/ProQuest. |
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