Localization of lysophosphatidylcholine in bovine chromaffin granules.
One of the unique features of the chromaffin granule membrane is the presence of about 17 mol% lysophosphatidylcholine. Lysophosphatidylcholine isolated from the granules could be degraded by approx. 94% by lysophospholipase. This result is consistent with chemical analyses data showing that about 9% of this lysophospholipid is 1'-alkenyl glycerophosphocholine. The localization of the acylglycerophosphocholine in the chromaffin granule membrane was studied by using pure bovine liver lysophospholipases. In intact granules only about 10% of the total lysophosphatidylcholine was directly available for enzymic hydrolysis. In contrast, when granule membranes (ghosts) were treated with lysophospholipases approx. 60% of the lysophosphatidylcholine was deacylated. These values did not increase after pre-treatment of intact granules or ghosts with trypsin. Added 1-[1-14C]palmitoyl-sn-glycero-3-phosphocholine did not mix with the endogenous lysophosphatidylcholine pool(s) and remained completely accessible to added lysophospholipases.
D000311:Adrenal Glands / Q000032:analysis; D000818:Animals; D002417:Cattle; D002458:Cell Fractionation; D002837:Chromaffin Granules / Q000032:analysis*; D002838:Chromaffin System / Q000032:analysis*; D007425:Intracellular Membranes / Q000032:analysis*; D007700:Kinetics; D008244:Lysophosphatidylcholines / Q000032:analysis*; D010740:Phospholipases / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis
D008244:Lysophosphatidylcholines; D010743:Phospholipids; D010740:Phospholipases