title: Partitioning of an anchor dipeptide in a phospholipid membrane.
abstract: We explore the localization of a guest N-myristoylated methyl glycine anchor dipeptide in a phospholipid environment. The dipeptide is part of a conservative sequence, which ensures proper association of a wide group of proteins in living organisms with a cellular phospholipid membrane. Using linear and two-color anharmonic infrared spectroscopy, we measure relative degrees of hydration of the amide I modes of the dipeptide and of phospholipid carbonyls. The atomic density of water in dependence of the distance from the hydrophobic center of the bilayer (a result of an independent Neutron scattering experiment) allows us to determine the relative altitudes of the peptide carbonyls with respect to those of the phospholipid ones. Considering this, and the dimensions of the dipeptide molecular frame, we anticipate the average angle between the backbone of the dipeptide and the normal to the membrane surface. The results provide a descriptive picture of the depth and geometry of partitioning of a guest N-myristoylated methyl glycine anchor dipeptide into a phospholipid membrane.
authors.affiliation: European Laboratory for Nonlinear Spectroscopy (LENS), Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy. vvolkov@lens.unifi.it
authors.forename: Victor V
authors.initials: VV
authors.lastname: Volkov
authors.forename: Roberto
authors.initials: R
authors.lastname: Righini
mesh_terms: D004151:Dipeptides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004151:Dipeptides; D008051:Lipid Bilayers; D010743:Phospholipids