Re: Gradient gels
Lyuben Marekov (lmarekov@Box-l.nih.gov)
Wed, 1 Apr 1998 12:54:12 +0200
>Hello folks,
> I do not normally run gradient gels and I do not have the
>apparatus to make them with. Has anyone any experience with precast gels
>(Novex comes to mind and is available in the U.K.) I worry about
>artifacts affecting the N-termini, as we screen all our reagents and
>pre-run the gels to maximise initial yield. Any suggestions gratefully
>received.
>Regards from Scotland,
>Bryan.
>--
>Bryan Dunbar,
>Protein Facility,
>Room WT27,
>Department of Molecular & Cell Biology,
>University of Aberdeen,
>Polwarth Building,
>Foresterhill,
>Aberdeen,
>SCOTLAND.
>AB25 2ZD.
>TEL: 01224-273103
>FAX: 01224-273104
>e-mail; b.dunbar@abdn.ac.uk
Bryan,
We routinely use Novex (gradient and non-gradient) gels. We consistently
observe modification of cysteine by acrylamide to S-propionamido-cysteine
No appreciable loss of alfa amino-group has been found in subsequent
sequencing. For this reason we never bothered to quantitate if any existed.
This modification of cys in most cases is useful, becouse the PTH-Cys-S-PAM
peak is coveniently separated from the other PTH amino acids. On the Porton
sequencer it elutes after PTH-Glu, and some free acid: PTH-Cys-S-PAA elutes
between PTH_HIS AND PTH_ALA
Lyuben
Lyuben N. Marekov
NIH, NIAMS
Bldg 6/Room 128
Bethesda, MD 20892-2752
phone (301)-496-7190
fax (301)-402-2886