Hey ABRFers-
I need some help.
Do you believe that I should be able to separate an octapeptide from its dimer? And if so, by what technique?
I have a well-characterized 8-mer that is just the niftiest little peptide you'd ever want to see, but upon storage in the lyophilized state, it loses activity. We have shown that there is no chemical modification of the peptide, and if we treat the stored peptide with urea, we can recover activity. Therefore, we think the peptide aggregates in storage. Also, we have shown that an earlier, larger version of this peptide, a 34-mer, does indeed aggregate in a very complex manner during storage in the lyophilized state. The 8-mer does not aggregate to a huge complex, so I think it is a dimer, maybe a trimer at largest. But I can see no resolution on high pressure gel filtration chromatography. I believe that I will never see much resolution, even if I hink around with pH, buffers, temperature, whatever. But I'd sure hate to be wrong about that. Do you think it is worthwhile trying harder to separate 8-mer from 16-mer? HPLC? Low pressure gel filtration? analytical ultr!
acentrifugation? Any other thoughts?
Thanks!
Tom
Ø------------------------
Thomas T. Andersen, Ph.D.
Director, Protein Chemistry Core Facility
Albany Medical College
Albany, NY 12208
518 262-5368
anderst@mail.amc.edu
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