Acyl-binding/lipid-transfer proteins from rape seedlings, a novel category of proteins interacting with lipids.
From rape (Brassica napus) seedlings proteins able to bind fatty acids and their CoA-esters were purified by gel filtration and cation-exchange chromatography. Among the four proteins detected, one of them (peak IV) appeared purified to homogeneity. This protein is a monomer with a molecular mass of about 9 kDa, as estimated by gel filtration and by polyacrylamide gel electrophoresis. The isoelectric point of the rape protein was higher than 10.5 as determined by chromatofocusing. The pure rape protein appeared furthermore to be able to transfer several phospholipids (phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine) between membranes. The rape protein, having a multifunctional property, was thus called acyl-binding/lipid-transfer protein (AB-LTP). In order to compare this protein to plant lipid-transfer proteins (LTPs), its structure was determined. The amino acid analysis of the rape AB-LTP revealed a high amount of alanine, an absence of histidine and tryptophan and the presence of eight cysteine residues. The N-terminal amino acid sequence of the rape protein revealed a high homology to plant LTPs. These observations led us to propose that the rape AB-LTPs belong to a category of plant proteins interacting with lipids and playing a role in the fatty acid dynamics.
Laboratoire de Physiologie Cellulaire et Moléculaire (C.N.R.S., U.R.A. 1180), Université Pierre et Marie Curie, Paris, France.
J
J
Ostergaard
C
C
Vergnolle
F
F
Schoentgen
J C
JC
Kader
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D052179:Antigens, Plant; D001937:Brassica / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003065:Coenzyme A / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009363:Neoplasm Proteins; D010743:Phospholipids / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification*; D016415:Sequence Alignment; D013379:Substrate Specificity
D000596:Amino Acids; D052179:Antigens, Plant; D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins; D010743:Phospholipids; D010940:Plant Proteins; C511920:lipid transfer proteins, plant; D003065:Coenzyme A