Incorporation of arachidonic acid (AA) into phosphatidylcholine molecular species of the human neutrophil (PMN)

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7246126

Chilton, F H; Murphy, R C

Recently the authors proposed that the initial incorporation of AA into 1,2 diacylphosphatidylcholine (PC) was mediated by AA-CoA transferase(s) while the subsequent transfer of AA from 1,2-diacyl- into alkyl, acyl-PC was mediated by a CoA-independent transacylase. Studies here provide further evidence for such a two-step mechanism. PMNs were pulse labeled for 5 min with /sup 3/H-AA (.07..mu..M) which was rapidly incorporated into 1,2-diacyl-PC. However, incorporation of AA into 1,2-diacyl-PC was inhibited by incubation with high levels of AA (30 ..mu..M). Similarly PMNs were pulsed labeled with /sup 3/H-AA for 5 min followed by a 120 min incubation. In these cells, /sup 3/H-AA was rapidly transferred from 1,2-diacyl-PC into alkyl, acyl-PC. In the presence of 30 ..mu..M AA redistribution of /sup 3/H-AA from diacyl to alkyl, acyl-PC was observed. This result implied that the initial incorporation of /sup 3/H-AA proceeds via a free acid intermediate while the transfer of /sup 3/H-AA from diacyl to alkyl, acyl-PC does not. Using a cell free system, /sup 14/C-AACoA was incubated for 5 min and found to be incorporated into 1,2-diacyl-PC containing 16:0, 18:0, and 18:1 at the sn-1 position. Furthermore /sup 14/C-AACoA and various 1-radyl, 2-lyso-PC were added to a PMN membrane preparation. The arachidonyl-transferase(s) preferred the 1-acyl, 2-lyso-PC substrate to 1-alkyl, 2-lyso-PC. Thus these studies provide further evidence that AA is initially incorporated into 1,2-diacyl-PC through arachidonyl-CoA transferases.

• Research Organization: Univ. of Colorado Medical School, Denver
• OSTI ID: 7246126
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ARACHIDONIC ACID
BIOLOGICAL MATERIALS
BIOSYNTHESIS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
ENZYME ACTIVITY
ENZYMES
ESTERS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LABELLING
LEUKOCYTES
LIPIDS
MAMMALS
MAN
MATERIALS
METABOLISM
MONOCARBOXYLIC ACIDS
NEUTROPHILS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
PRIMATES
SYNTHESIS
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
VERTEBRATES