Phospholipid-induced structural changes to an erythroid beta spectrin ankyrin-dependent lipid-binding site.
The region of beta-spectrin that is responsible for interactions with ankyrin was shown to comprise an ankyrin-sensitive lipid-binding site. Structural studies indicate that it exhibits a mixed 3(10)/alpha helical conformation and is highly amphipathic. These features together with the distinctively conserved sequence of the lipid-binding site motivated us to explore the mechanism of its interactions with biological membranes. A series of singly and doubly spin-labeled erythroid beta-spectrin-derived peptides was constructed, and the spin-label mobility and spin-spin distances were analyzed via electron paramagnetic resonance spectroscopy and two different calculation methods. The results indicate that in beta-spectrin, the lipid-binding domain, which is part of the 14(th) segment, has the topology of typical triple-helical spectrin repeat. However, it undergoes significant changes when interacting with phospholipids or detergents. A mechanism for these interactions is proposed in this paper.
Czogalla
Aleksander
A
Faculty of Biotechnology, University of Wrocław, ul. Przybyszewskiego 63/77, 51-148 Wrocław, Poland.
Grzymajło
Krzysztof
K
Jezierski
Adam
A
Sikorski
Aleksander F
AF
D001665:Binding Sites / Q000187:drug effects; D002942:Circular Dichroism; D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D010743:Phospholipids / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D013049:Spectrin / Q000737:chemistry*; D013113:Spin Labels; D013696:Temperature
D010455:Peptides; D010743:Phospholipids; D013113:Spin Labels; D013049:Spectrin