Identification of phosphatidylserine-binding proteins in human white blood cells.
Cytosol and membrane fractions from human neutrophils, monocytes, lymphocytes and platelets were separated by SDS/PAGE, blotted on to nitrocellulose and assayed for selective binding of phosphatidylserine (PS). Two PS-binding proteins with apparent molecular masses of 115 kDa and 100 kDa were identified in the cytosol of neutrophils, monocytes and lymphocytes. Corresponding bands along with other PS-binding proteins were detected in platelets in both cytosol and membrane fractions. These proteins were also found to bind protein kinase C (PKC) provided that PS was present. The 115 kDa and 100 kDa proteins (PS-p115/110) were partially purified from neutrophils and were used for the study of PS and PKC binding. The binding of PS did not require Ca2+ or Mg2+ and was inhibited by phosphatidic acid, by 1-alkyl-2-acetylphosphocholine and, to a lesser extent, by other lipids. The binding of PKC, however, was strictly PS- and Ca2(+)-dependent and seems to occur secondarily to PS binding.
Wolf
M
M
Theodor Kocher Institut, Universität Bern, Switzerland.
Baggiolini
M
M
D001798:Blood Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002352:Carrier Proteins / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D003101:Collodion / Q000378:metabolism; D003600:Cytosol / Q000032:analysis / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007962:Leukocytes / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D009504:Neutrophils / Q000032:analysis / Q000378:metabolism / Q000648:ultrastructure; D010718:Phosphatidylserines / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding; D011493:Protein Kinase C / Q000097:blood
D001798:Blood Proteins; D002352:Carrier Proteins; D010718:Phosphatidylserines; D003101:Collodion; D011493:Protein Kinase C