TY - JOUR
T1 - A glycan-phosphatidylinositol-specific phospholipase D in human serum
AU - Davitz, Michael A.
AU - Hereld, Dale
AU - Shak, Steve
AU - Krakow, Jessica
AU - Englund, Paul T.
AU - Nussenzweig, Victor
PY - 1987
Y1 - 1987
N2 - A group of proteins anchored to the cell by phosphatidylinositol (PI) has recently been identified. The significance of this new class of membrane anchor is unknown; one possibility is that it facilitates release of the molecule by phospholipases. In fact, phospholipase C enzymes specific for the complex carboxyl-terminal glycolipids of these proteins have been isolated from African trypanosomes and from hepatocyte plasma membranes. This study reports the discovery of a glycan-PI-specific phospholipase D in human serum that cleaves both the membrane form of the variant surface glycoprotein of African trypanosomes and its glycolipid precursor, but not phosphatidylethanolamine, phosphatidylcholine, or phosphatidylinositol. Decay-accelerating factor, another PI-anchored molecule, is also cleaved by the enzyme and converted from a hydrophobic to a soluble protein. The enzyme is Ca2+-dependent, heat labile, and not affected by the inhibitor of serine proteases, phenylmethylsulfonylfluoride. Its function is not known, but the present findings indicate that it participates in the metabolism of glycolipid-anchored membrane proteins.
AB - A group of proteins anchored to the cell by phosphatidylinositol (PI) has recently been identified. The significance of this new class of membrane anchor is unknown; one possibility is that it facilitates release of the molecule by phospholipases. In fact, phospholipase C enzymes specific for the complex carboxyl-terminal glycolipids of these proteins have been isolated from African trypanosomes and from hepatocyte plasma membranes. This study reports the discovery of a glycan-PI-specific phospholipase D in human serum that cleaves both the membrane form of the variant surface glycoprotein of African trypanosomes and its glycolipid precursor, but not phosphatidylethanolamine, phosphatidylcholine, or phosphatidylinositol. Decay-accelerating factor, another PI-anchored molecule, is also cleaved by the enzyme and converted from a hydrophobic to a soluble protein. The enzyme is Ca2+-dependent, heat labile, and not affected by the inhibitor of serine proteases, phenylmethylsulfonylfluoride. Its function is not known, but the present findings indicate that it participates in the metabolism of glycolipid-anchored membrane proteins.
UR - http://www.scopus.com/inward/record.url?scp=0023193114&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023193114&partnerID=8YFLogxK
U2 - 10.1126/science.2443973
DO - 10.1126/science.2443973
M3 - Article
C2 - 2443973
AN - SCOPUS:0023193114
SN - 0036-8075
VL - 238
SP - 81
EP - 84
JO - Science
JF - Science
IS - 4823
ER -