TY - JOUR

T1 - Association of acylated cationic decapeptides with dipalmitoylphosphatidylserine-dipalmitoylphosphatidylcholine lipid membranes

AU - Pedersen, Tina B.

AU - Sabra, Mads C.

AU - Frokjaer, Sven

AU - Mouritsen, Ole G.

AU - Jørgensen, Kent

PY - 2001/11/7

Y1 - 2001/11/7

N2 - The interaction of three acylated and cationic decapeptides with lipid membranes composed of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylserine (DPPS) has been studied by means of fluorescence spectroscopy and differential scanning calorimetry (DSC). The synthetic model decapeptides that are N-terminally linked with C2, C8, and C14 acyl chains contain four basic histidine residues in their identical amino acid sequence. A binding model, based on changes in the intrinsic fluorescent properties of the peptides upon association with the DPPC-DPPS membranes, is used to estimate the peptide-membrane dissociation constants. The results clearly show that all three peptides have a higher affinity to liposomes containing DPPS lipids due to non-specific electrostatic interactions between the cationic peptides and the anionic DPPS lipids. Furthermore, it is found that the acyl chain length of the peptides plays a crucial role for the binding. A preference for fluid phase membranes as compared to gel phase membranes is generally observed for all three peptides. DSC is used to characterise the influence of the three peptides on the thermodynamic phase behaviour of the binary DPPC-DPPS lipid mixture. The extent of peptide association deduced from the heat capacity measurements suggests a strong binding and membrane insertion of the C14 acylated peptide in accordance with the fluorescence measurements.

AB - The interaction of three acylated and cationic decapeptides with lipid membranes composed of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylserine (DPPS) has been studied by means of fluorescence spectroscopy and differential scanning calorimetry (DSC). The synthetic model decapeptides that are N-terminally linked with C2, C8, and C14 acyl chains contain four basic histidine residues in their identical amino acid sequence. A binding model, based on changes in the intrinsic fluorescent properties of the peptides upon association with the DPPC-DPPS membranes, is used to estimate the peptide-membrane dissociation constants. The results clearly show that all three peptides have a higher affinity to liposomes containing DPPS lipids due to non-specific electrostatic interactions between the cationic peptides and the anionic DPPS lipids. Furthermore, it is found that the acyl chain length of the peptides plays a crucial role for the binding. A preference for fluid phase membranes as compared to gel phase membranes is generally observed for all three peptides. DSC is used to characterise the influence of the three peptides on the thermodynamic phase behaviour of the binary DPPC-DPPS lipid mixture. The extent of peptide association deduced from the heat capacity measurements suggests a strong binding and membrane insertion of the C14 acylated peptide in accordance with the fluorescence measurements.

KW - Acylated peptide

KW - Calorimetry

KW - DPPC-DPPS lipid mixture

KW - Peptide-membrane association

KW - Tryptophan fluorescence

UR - http://www.scopus.com/inward/record.url?scp=0034778935&partnerID=8YFLogxK

U2 - 10.1016/S0009-3084(01)00177-3

DO - 10.1016/S0009-3084(01)00177-3

M3 - Journal article

C2 - 11687229

AN - SCOPUS:0034778935

VL - 113

SP - 83

EP - 95

JO - Chemistry and Physics of Lipids

JF - Chemistry and Physics of Lipids

SN - 0009-3084

IS - 1-2

ER -