Hi Mary,
Glucosamine (GluN) has a neutral mass of 161; it is present only in
glycosylphosphatidylinositol [PI-GluN-(mann)3-PEtN] molecules and rarely
(never, as far as I know; but could be ignorant!) in N-linked
oligosaccharides. The identity of GluN can be ascertained chemically [see
P Schnieder and MAJ. Ferguson 1995, Methods Enzymol. 250: 614--630; M.A.J.
Ferguson 1992, In NM Hooper and AJ Turner eds. "Lipid modification of
proteins, a practical approach" (IRL press, Oxford) pp191--230].
Hope this helps.
sebastian
Sebastian Joyce, Ph.D.
DEPARTMENT OF MICROBIOLOGY & IMMUNOLOGY
THE PENNSYLVANIA STATE UNIVERSITY COLLEGE OF MEDICINE
MILTON S. HERSHEY MEDICAL CENTER
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