Formation of non-bilayer structures induced by M13 coat protein depends on the conformation of the protein.
A comparison is made of the interaction of the coat protein of bacteriophage M13 in a predominant alpha-helix conformation and in a predominant beta-sheet conformation. To perform a systematic study of the interaction between the protein in these two different forms of the surrounding lipid matrix, NMR spectra of 2H-nuclei of specific labelled phospholipid systems are measured. In addition 31P-NMR is employed to provide information about the morphological structure adopted by the reconstituted lipid/protein systems. From the 2H-NMR studies on specific headgroup and chain deuterium labelled phospholipids it is found that the protein in the predominant beta-sheet conformation causes a fraction of lipids to be trapped. By combining the results from the headgroup and acyl chains of the phospholipids, it is concluded that the trapped lipids are arranged in a non-bilayer structure, probably caused by a misfitting of the hydrophobic core of the protein and the membrane bilayer. The protein in the predominant alpha-helix conformation perfectly fits in the lipid bilayer and has only minor influences on the surrounding lipid matrix. A new model is proposed to explain the presence of the trapped lipids in the lipid/protein systems.
Sanders
J C
JC
Department of Molecular Physics, Agricultural University, Wageningen, Netherlands.
Poile
T W
TW
Wolfs
J A
JA
Hemminga
M A
MA
D017104:Bacteriophage M13; D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins; D003903:Deuterium; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D010759:Phosphorus Isotopes; D011487:Protein Conformation
D036022:Capsid Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010713:Phosphatidylcholines; D010759:Phosphorus Isotopes; C025668:coat protein, Bacteriophage M13; D003903:Deuterium; C017251:1,2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine