The peptide does not contain any acidic or basic residues and it is capped on the ends. We tried to dissolve the peptide in several organic solvents. It dissolved in some of the solvents, but crashed out of solution as soon as we added water or water with 0.1% TFA. We found that the peptide dissolves in 6M GdnHCl and that we can put this on our HPLC (C18 column) and purify out the peptide using gradients of water and acetonitrile, both containing 0.1% TFA.
Hi Kristi,
Some amino acids, such as lysine can be guadinylated when dissolved in high concentrations of GdnHCl, especially when heated. But if your peptide does not contain amino acids that are prone to this reaction (and it sounds like that's the case), you should be fine using that solvent to enable peptide purification.
Good luck!
Guanidine is routinely used to solubilize crude peptide for purification as long as you don't store the peptide in guanidinium solution you are fine. I solubilize the peptide in guanidine and filter it and use for purification within hours on c18 column and have not seen much of problem. As Dirksen mention guanidylation can be observed if you store it in 6M gdn solution for days.
Thank you for your help! We are looking forward to working with our pure peptide.
- Badges
- Science topic