Premium
Evidence that biosynthesis of platelet‐activating factor (paf‐acether) by human neutrophils occurs in an intracellular membrane
Author(s) -
Ribbes Gérard,
Ninio Ewa,
Fontan Pascal,
Record Michel,
Chap Hugues,
Benveniste Jacques,
Douste-Blazy Louis
Publication year - 1985
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(85)80007-7
Subject(s) - platelet activating factor , intracellular , biosynthesis , chemistry , platelet , microbiology and biotechnology , biochemistry , immunology , biology , enzyme
Human polymorphonuclear leukocytes (PMN) were incubated in the absence or presence of the calcium ionophore A23187 (6μM) for 10 min at 37°C. They were then lysed by nitrogen cavitation and fractionated using Percoll gradients. Three major fractions of increasing density corresponding to plasma membrane, intracellular membranes and secretory granules were detected using [ 3 H]concanavalin A, NADH‐dehydrogenase and β‐D‐glucuronidase as respective markers. In both cases, the acetyltransferase activity responsible for biosynthesis of paf‐acether (platelet‐activating factor of 1‐ O ‐alkyl‐2‐acetyl‐ sn ‐glycero‐3‐phosphocholine) was detected in the intermediary fraction, the enzyme activity being increased 3‐4‐fold in stimulated cells. From the comparison with the distribution of various markers, it is concluded that in human PMN the final step of paf‐acether assembly occurs in an intracellular membrane, possibly the endoplasmic reticulum.