Evidence for Surface Recognition by a Cholesterol-Recognition Peptide.
Two cholesterol recognition/interaction amino-acid consensus peptides, N-acetyl-LWYIKC-amide, and N-acetyl-CLWYIK-amide, have been coupled to exchangeable mimics of Chol (cholesterol) and Phos (1,2-dipalmitoyl-sn-glycerol-3-phospho-(1'rac-glycerol)) via disulfide bond formation. Equilibration between Chol and Phos via thiolate-disulfide interchange reactions has revealed that both peptides favor Chol as a nearest-neighbor in liquid-disordered (ld) bilayers to the same extent. In contrast, no Chol- or Phos-recognition could be detected by these peptides in analogous liquid-ordered (lo) bilayers. Fluorescence measurements of the tryptophan moiety have shown that both peptides favor the membrane-water interface. Taken together, these results provide strong evidence that the recognition behavior of the LWYIK motif is, fundamentally, a surface phenomenon but that partial penetration into the bilayer is also necessary.
Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania.
Masaru
M
Mukai
Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania.
Kerney Jebrell
KJ
Glover
Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania. Electronic address: slr0@lehigh.edu.
Steven L
SL
Regen
D002784:Cholesterol / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D010715:Phosphatidylglycerols / Q000737:chemistry; D055503:Protein Multimerization; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D008051:Lipid Bilayers; D008081:Liposomes; D010455:Peptides; D010715:Phosphatidylglycerols; D014867:Water; D002784:Cholesterol; C030345:1,2-dipalmitoylphosphatidylglycerol