I have a low Mol. Wt. glycopeptide (~20kD) isolated from a yeast that is
heavily glycosylated, mainly with mannose. The majority of the linkages
are reducing termini and 1->2 linked. There are low levels of other
linkages and other sugars. The major amino acids are serine(20) and
threonine(17); alanine(13); aspartic acid (11) and glutamic acid (11);
glycine (4), valine (4), leucine (5), and proline (6). No histidine,
lysine, others >1. Amino acids released from the deglycosylated pepitide
are serine, aspartic acid, threonine, alanine, and valine. At the third
cycle the amino acids are the same and in a constant ratio. Aspartic acid
and serine are released from the glycosylated peptide only during the first
sequencing cycle. No release occurs on additional sequence cycles. The
peptide is responsible for cell mediated immunity to the yeast.
Is this a common structural motif for a O-glycosylated peptide?
Any other comments are welcome.
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Dr. Robert Cherniak Voice: (404)651-3868
Dept. of Chemistry Fax: (404)651-1416
Georgia State University E-mail: cherniak at gsu.edu
Atlanta, GA 30303
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