Interaction of alpha s2- and beta-casein signal peptides with DMPC and DMPG liposomes.
Interactions of casein signal peptides (CSP) and derivatives were detected with dimyristoylphosphatidyl-glycerol and -choline liposomes. Fluorescence anisotrophy indicated that the peptides interact better with DMPG than DMPC, inserting at a limited depth in the bilayer. Stronger interaction was detected for derivatives of beta-CSP than of alpha s2-CSP. Tryptophan fluorescence (intrinsic, energy transfer, quenching) showed that the central hydrophobic core of CSP was buried in the bilayer whereas both ends remained outside, adopting a hairpin-like conformation. The secondary structure of the CSP was not affected by their interactions with phospholipids. beta-CSP derivatives show both lytic and fusogenic activities.
Creuzenet
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C
Institut National de la Recherche Agronomique, LEIMA, Nantes, France.
Durand
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C
Haertlé
T
T
D000595:Amino Acid Sequence; D002364:Caseins / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D005454:Fluorescence Polarization; D016014:Linear Models; D008081:Liposomes / Q000737:chemistry; D008969:Molecular Sequence Data; D010715:Phosphatidylglycerols / Q000737:chemistry*; D021382:Protein Sorting Signals / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry
D002364:Caseins; D008081:Liposomes; D010715:Phosphatidylglycerols; D021382:Protein Sorting Signals; D014364:Tryptophan; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine