Cytosolic lysophosphatidylcholine/transacylase in the production of dipolyunsaturated phosphatidylcholine in bonito muscle.
Phosphatidylcholine with docosahexaenoic acid at both sn-1 and sn-2 positions occurs in relatively high abundance in bonito muscle. To explore a possible route for the dipolyunsaturated molecular species, phosphatidylcholine formation from 2-[1-14C]linoleoyl lysophosphatidylcholine was examined using a cytosolic fraction from bonito muscle. The formation of radiolabeled phosphatidylcholine was greatest at 15 degrees C and did not require the presence of cofactors such as CoA and calcium. By DEAE-cellulofine column chromatography, the activity to form phosphatidylcholine was separated from that of phospholipase A1, and the specific activity increased by about 100-fold. The possible involvement of cytosolic lysophosphatidylcholine/transacylase in synthesis of dipolyunsaturated phosphatidylcholine is discussed.
Hirano
K
K
Department of Food Science and Technology, Fukuyama University, Hiroshima, Japan.
Ito
T
T
Morihara
H
H
Tanaka
T
T
Satouchi
K
K
D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D003600:Cytosol / Q000201:enzymology*; D004789:Enzyme Activation; D005399:Fishes; D008245:Lysophospholipase / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010741:Phospholipases A / Q000378:metabolism; D054466:Phospholipases A1; D014413:Tuna
D009097:Multienzyme Complexes; D010713:Phosphatidylcholines; D000217:Acyltransferases; D010741:Phospholipases A; D054466:Phospholipases A1; D008245:Lysophospholipase; C021782:lysophospholipase-transacylase