Has anyone had experience in analysing sulfated protein(or peptides)?
I have limited myself to the detection of Tyrosine sulfate,because related
proteins are
sulfated at that residues.Sulfoglycosylation is another problem.The first
problem is that
there is known(to me) standard.We synthesized a bit,and,then deprotected
Fmoc tyrosine
sulfate,giving peaks which coeluted,and yielded free tyrosine on acid
hydrolysis.Now,base
hydrolysis is needed to get tyrosine sulfate,and that is where we have been
running into
trouble.The base is removed by precipitattion,either barium hydroxide as
sulfate or KOH as
perchlorate.This works ok in the 20-50 microgram range,but when sensitivity
is essential
the A.A.A. look like the product of a kitchen sink.I am using the AccQ-Tag
chemistry for
analysis.Thank you very much.
Fulvio Perini,Ph.D.
986805 Nebraska Med.Cntr.
Omaha,NE 68198-6805
ph:402-559-6184/FAX 402-559-4651
fperini@unmc.edu
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