Ligatin: a peripheral membrane protein with covalently bound palmitic acid.
The ligatin monomer is a polypeptide of Mr = 10,000 which is soluble in acidified chloroform:methanol, a characteristic similar to that of Folch-Lee proteolipid. The hydrophobicity of ligatin is also reflected by its ability to interpolate into the phosphatidylcholine bilayer as shown by a concentration-dependent change in membrane conductance. However, unlike other proteolipids the amino acid composition of ligatin is not enriched in hydrophobic amino acids (isoleucine, leucine, valine, methionine, phenylalanine, tryptophan). Instead, the hydrophobic character of ligatin could be explained, at least in part, by the covalent association of fatty acids, 1.4-1.7 mol of palmitate/10,000 g of protein, as revealed by gas chromatography mass spectrographic analyses. The post-translational addition of fatty acid may therefore be the means by which ligatin acquires an affinity for membranes.
D000215:Acylation; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D004553:Electric Conductivity; D008401:Gas Chromatography-Mass Spectrometry; D007082:Ileum / Q000032:analysis; D008051:Lipid Bilayers / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D051381:Rats
D000596:Amino Acids; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010169:Palmitic Acids; D010713:Phosphatidylcholines; C013090:ligatin; D019308:Palmitic Acid