Structural insight into an ankyrin-sensitive lipid-binding site of erythroid beta-spectrin.
It was recently shown that the region within beta-spectrin responsible for interactions with ankyrin includes a lipid-binding site which displayed sensitivity to inhibition by ankyrin. We studied its structure by constructing a series of single and double spin-labeled beta-spectrin-derived peptides and analyzing their spin-spin distances via electron paramagnetic resonance spectroscopy and the Fourier deconvolution method. The results indicate that the whole ankyrin-sensitive lipid-binding site of beta-spectrin exhibits a helical conformation revealing a distinct 3(10)-helix contribution at its N-terminus. The start of the helix was located five residues upstream along the sequence compared to the theoretical predictions. A model based on the obtained data provides direct evidence that the examined lipid-binding site is a highly amphipathic helix, which is correlated with the specific conformation of its N-terminal fragment.
Czogalla
Aleksander
A
Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland.
Jaszewski
Adrian R
AR
Diakowski
Witold
W
Bok
Ewa
E
Jezierski
Adam
A
Sikorski
Aleksander F
AF
D000818:Animals; D017487:Ankyrins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D003198:Computer Simulation; D003545:Cysteine / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000378:metabolism*; D005583:Fourier Analysis; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D013049:Spectrin / Q000737:chemistry / Q000378:metabolism*; D013113:Spin Labels; D013329:Structure-Activity Relationship
D017487:Ankyrins; D008055:Lipids; D013113:Spin Labels; D013049:Spectrin; D003545:Cysteine