Surface-induced conformational switching in amphiphilic peptide segments of apolipoproteins B and E and model peptides.
The conformational and surface-binding properties of a synthetic peptide corresponding to Tyr-apolipoprotein B-100(1000-1016) amide, SP-4, which was previously shown to mimic the focal accumulation pattern of LDL on the healing de-endothelialized rabbit aorta [Shih et al. (1990) Proc. Natl. Acad. Sci. USA 87, 1436-1440], have been investigated. SP-4 behaves as an amphiphilic alpha-helical peptide at the air-water interface and bound to siliconized quartz slides. However, its N alpha-acetylated analogue formed beta-sheet structures at the air-water interface. Nonhomologous peptide models of SP-4 also exhibited mixed alpha-helical and beta-sheet surface-binding behavior. Peptides corresponding to the cationic apolipoprotein (apo) B/E receptor binding regions of apoE (SP-2) and apoB (SP-11) were also studied. SP-2 behaved as an amphiphilic alpha helix, but, surprisingly, SP-11 formed surface-induced beta-sheets. These results demonstrate that all of the peptides studied have surface-binding properties, and suggest further that either alpha-helical or beta-sheet peptide structures may determine the binding of LDL to the arterial wall or the apoB/E receptor.
Taylor
J W
JW
Department of Chemistry, Rutgers University, Piscataway, New Jersey.
Shih
I L
IL
Lees
A M
AM
Lees
R S
RS
D000595:Amino Acid Sequence; D001055:Apolipoproteins B / Q000737:chemistry*; D001057:Apolipoproteins E / Q000737:chemistry*; D002942:Circular Dichroism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
D001055:Apolipoproteins B; D001057:Apolipoproteins E; D010446:Peptide Fragments; D012996:Solutions