breakbta.blogg.se - Hydrophobic amino acids cell membrane

Biochim Biophys Acta 1111: 171–177Ĭhakrabarti AC, Clark-Lewis I, Harrigan PR, Cullis PR (1992) Uptake of basic amino acids and peptides into liposomes in response to transmembrane pH gradients. Chem Phys Lipids 33: 303–312Ĭhakrabarti AC, Deamer DW (1992) Permeability of lipid bilayers to amino acids and phosphate. FEBS Lett 99: 210–213Ĭantenys D, Dogounkoff C, Massol M (1983) Permeability of liposomes towards amino alcohol and amino acid nitroxides. J Mol Biol 13: 238–257īarenholtz Y, Amselem S, Lichtenberg D (1979) A new method for preparation of phospholipid vesicles (liposomes) - French press. These results may relate to the movement of peptides through membranes during protein translocation and to the origin of cellular membrane transport on the early Earth.īangham AD, Standish MM, Watkins JD (1965) Diffusion of univalent ions across the lamellae of swollen phospholipids. It was also shown that charge distributions dramatically alter permeation rates for modified di-peptides.

s −1) as neutral (deprotonated) molecules.

It was established that lysine methyl ester and other modified short peptides permeate rapidly ( P = 10 −2 cm Hydrophobic amino acids were 10 2 more permeable than the hydrophilic forms, reflecting their increased partition coefficient values.Įxternal pH had dramatic effects on the permeation rates for the modified amino acid lysine methyl ester in response to transmembrane pH gradients. This observation suggests that the permeation rates for the neutral, polar and charged amino acids are controlled by bilayer fluctuations and transient defects, rather than partition coefficients and Born energy barriers. The permeability coefficients for most amino acids tested were surprisingly similar to those previously measured for monovalent cations such as sodium and potassium (approximately 10 −12–10 −13 cm

Increasing the membrane surface charge increased the permeability of amino acids of the opposite charge, while increasing the cholesterol content decreased membrane permeability. Decreasing lipid chain length increased permeability slightly (5-fold), while variations in pH had only minor effects on the permeability coefficients of the amino acids tested in liposomes. Membrane permeability coefficients ( P) for amino acid classes, including neutral, polar, hydrophobic, and charged species, have been measured and compared using a variety of techniques. The amino acid permeability of membranes is of interest because they are one of the key solutes involved in cell function.