Four 9-kDa proteins excreted by somatic embryos of grapevine are isoforms of lipid-transfer proteins.
Four 9-kDa small extracellular proteins produced by embryogenic cultures in the absence of auxin have been purified from the extracellular medium of grapevine somatic embryo cultures through cation-exchange chromatography and hydrophobic-interaction chromatography. The partial amino-acid sequences reflect high similarities between the four proteins as well as with the sequences established for carrot, spinach, millet and maize nonspecific lipid-transfer proteins. All these sequences show conservation of three cysteines at positions 4, 14 and 30-32, as well as glycine, valine, tyrosine and lysine residues at positions 5, 7, 17 and 37, respectively. In-vitro lipid-transfer assays reveal that the four proteins catalyze the transfer of phosphatidylcholine from liposomes towards mitochondria with an efficiency similar or higher than that of a purified maize lipid-transfer protein.
Coutos-Thevenot
P
P
Institut des Sciences Végétales, CNRS, Gif sur Yvette, France.
Jouenne
T
T
Maes
O
O
Guerbette
F
F
Grosbois
M
M
Le Caer
J P
JP
Boulay
M
M
Deloire
A
A
Kader
J C
JC
Guern
J
J
D000595:Amino Acid Sequence; D052179:Antigens, Plant; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002478:Cells, Cultured; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005638:Fruit / Q000737:chemistry*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C511920:lipid transfer proteins, plant