About peptide solubility
How to dissolve my peptide?
The solubility of peptides varies depending on its amino acid sequence and modifications. When we prepare it, the peptide is generally purified by HPLC using water and acetonitrile gradient. Here are some general tips for dissolving peptides:
- sonification will increase the solubility of peptides.
- For basic peptides, 10% acetic acid in the solvent will help dissolve peptides.
- For acidic peptides, 10% ammonium bicarbonate will help dissolve peptides
- For peptides with extremely low solubility in aqueous solutions, organic solvents should be used first (such as DMSO, isopropanol, methanol, acetonitrile). Once peptides are dissolved completely, water may be added slowly until the final concentration has been reached.
Do I need to solubilize my peptide under specific pH?
It will also be stated on your Certificate of Analysis if any specific PH level is requested.
What should I do if my peptide does not dissolve well?
As a general rule, peptides should first be dissolved in distilled, preferably sterile water. If solubility still remains a problem, try the following steps:
Sonication is helpful to dissolve the peptide
Small amounts of dilute(10%) aqueous acetic acid for basic peptides or aqueous ammonia for acidic peptides may help dissolution of these peptides.
It is also recommended that the peptide be dissolved to the possible concentration, and then diluted with water or buffer to the working concentration.(Note: The buffer should be added only after the peptide is completely in solution form because salts may cause aggregation).
Why the solubility may vary from one peptide to the other?
Solubility is often one of the major challenges for researchers who work with peptides. Each amino acid exhibits its own physical characteristics. Amino acids such as leucine, isoleucine, and valine are very hydrophobic. Other amino acids like lysine, histidine, and arginine are hydrophilic. Thus, different peptides will have different solubilities, based on the content of the peptides.
How do I solubilize my peptide?
All solubility information is reported on the Certificate of Analysis received with your peptide. Please read the instructions carefully before starting. Solubility may very depending on the nature of the peptide. The more common dissolution process is 1 mg of peptide distilled in 1 ml of sterile water.
