Glycosyl-phosphatidylinositol-specific phospholipase D. Interaction with and stimulation by apolipoprotein A-I.
Glycosyl-phosphatidylinositol-specific phospholipase D (GPI-PLD) is an amphiphilic protein which, in serum, is associated with high-density lipoproteins (HDL). It is shown that the major component of the HDL fraction, apolipoprotein A-I (apo A-I), is responsible for this association. In the absence of apo A-I, purified GPI-PLD occurred as virtually inactive aggregates which became disaggregated by apo A-I. The enzyme/apo A-I complex efficiently hydrolyzed the solubilized GPI-anchored substrate, acetylcholinesterase. Triton X-100 was also able to dissociate aggregated GPI-PLD, however, it strongly inhibited enzyme activity at detergent concentrations above the critical micellar concentration.
Hoener
M C
MC
Institute of Biochemistry and Molecular Biology, University of Bern, Switzerland.
Bolli
R
R
Brodbeck
U
U
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D016632:Apolipoprotein A-I / Q000378:metabolism*; D002417:Cattle; D002499:Centrifugation, Density Gradient; D002846:Chromatography, Affinity; D004789:Enzyme Activation; D010739:Phospholipase D / Q000378:metabolism*; D011485:Protein Binding
D016632:Apolipoprotein A-I; D000110:Acetylcholinesterase; D010739:Phospholipase D; C065017:glycoprotein phospholipase D