Structure of the glycosylphosphatidylinositol membrane anchor of human placental alkaline phosphatase.
The glycosylphosphatidylinositol membrane anchor of human placental alkaline phosphatase was isolated by exhaustive proteolysis followed by hydrophobic interaction chromatography. The resulting glycosylphosphatidylinositol-peptide was subjected to compositional analysis and chemical and enzymic modifications. The neutral-glycan fraction, prepared by dephosphorylation followed by HNO2 deamination and reduction, was sequenced using exoglycosidases and acetolysis. The phosphatidylinositol moiety was analysed by fast-atom bombardment mass spectrometry and gas chromatography-mass spectrometry. Taken together the data suggest the structure, Thr-Asp-ethanolamine-PO4-Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN-(sn-1-O- alkyl-2-O-acylglycerol-3-PO4-1-myo-D-inositol), which contains an additional ethanolamine phosphate group at an unknown position.
Redman
C A
CA
Department of Biochemistry, University of Dundee, U.K.
Thomas-Oates
J E
JE
Ogata
S
S
Ikehara
Y
Y
Ferguson
M A
MA
D000469:Alkaline Phosphatase / Q000737:chemistry*; D002240:Carbohydrate Sequence; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D017261:Glycosylphosphatidylinositols / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D010920:Placenta / Q000201:enzymology*; D016339:Spectrometry, Mass, Fast Atom Bombardment
D017261:Glycosylphosphatidylinositols; D000469:Alkaline Phosphatase