Abstract
This report describes the complete translated gene sequence, predicted secondary structure and lipid bilayer association of a novel kinetoplastid membrane protein (KMP-11) from Leishmania donovani promastigotes. KMP-11 was previously referred to as the lipophosphoglycan-associated protein (LPGAP). The isolation, species distribution and chemical characterization, including a partial protein sequence analysis and post-translational modifications, of this major membrane component have been described. C.d. measurements of KMP-11 indicated a very high helical content estimated to be approximately 86 % in trifluoroethanol. This was in agreement with computer-based secondary-structure analyses which predicted KMP-11 to be almost exclusively α-helical, with the protein adopting a helix-loop-helix motif. Arrangement of the residues located in the putative helical regions on an Edmundson helical wheel showed that this molecule could have a strongly amphipathic conformation and provided an explanation for how such a highly charged protein might be inserted into the plasma membrane. Evidence in support of KMP-11 association with lipid bilayers was provided by showing that KMP-11 could mediate carboxyfluorescein release from liposomes. These findings suggested that KMP-11 may function in part to increase bilayer pressure, stabilizing molecules such as lipophosphoglycan within the parasite pellicular membrane.
Original language | English (US) |
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Pages (from-to) | 315-320 |
Number of pages | 6 |
Journal | Biochemical Journal |
Volume | 305 |
Issue number | 1 |
DOIs | |
State | Published - 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology