At 02:57 PM 6/9/1999 +0800, leefeng wrote:
> I have modified some of cysteine residues of a polypeptide using IAA.
>I want to know the position of labled cysteine residues by sequence
>analysis. But there is no PTH-Cys-CAM in my PTH-AA standard. Could you
>tell me the position of PTH-Cys-CAM on PTH-AA standard chromatogram?
On our Hewlett-Packard sequencer, it runs between Gly and His -- nicely
separated from both.
If you use iodoacetic acid to generate the CM-Cys-PTH, it runs just after Glu
-- and will not fully separate from it, but the later time of the peak is quite
reproducible. We prefer using iodoacetamide to avoid ambiguity.
Rod Levine
NIH
Bldg 3, Room 106 MSC 0320
Bethesda, MD 20892-0320
email: rlevine@nih.gov
voice: 1 (301) 496-2310
fax: 1 (301) 496-0599
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At 02:57 PM 6/9/1999 +0800, leefeng wrote:
> I have modified some of cysteine residues of a polypeptide
using IAA.
>I want to know the position of labled cysteine residues by
sequence
>analysis. But there is no PTH-Cys-CAM in my PTH-AA standard. Could
you
>tell me the position of PTH-Cys-CAM on PTH-AA standard
chromatogram?
On our Hewlett-Packard sequencer, it runs between Gly and His -- nicely
separated from both.
If you use iodoacetic acid to generate the CM-Cys-PTH, it runs just after
Glu -- and will not fully separate from it, but the later time of the
peak is quite reproducible. We prefer using iodoacetamide to avoid
ambiguity.
Rod Levine
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