Question

What can you not mix with peptides?

Answer 1

Peptides:

1. They are naturally occurring short chains of amino acids (2-50 amino acids).
2. Amino acids are connected via amide bonds.
3. They include hormones, antibiotics, etc.
4. Example of peptide hormones- insulin, glucagon, etc.
5. Examples of peptide antibiotics- colistin, actinomycin, etc.
6. They are formed by the transcription of genetic codes(DNA sequence).
7. Also, larger proteins break down to form peptides.
8. Example- milk peptides are formed by the digestion of Casein protein.
9. Polypeptides fold to produce functionally active proteins.

Solubility of peptides:

1. It depends on the solubility of amino acids in the peptide.
2. Usually, the more charged residues the peptide possesses, the more soluble it is in aqueous solutions.
3. Peptides with ≥ 25% charged hydrophilic residues (water-repelling), are soluble in water or aqueous buffers.
4. Whereas, peptides with >50 % hydrophobic charged residues are soluble in non-aqueous solvents like ethanol, isopropyl alcohol, etc.
5. Peptides are usually not mixed with AHA (Alpha Hydroxy Acids) because acidic pH is undesirable for peptides.
6. AHA is a group of natural acids found in foods.
7. Example- citric acid (found in citrus fruits), tartaric acid (found in grapes), lactic acid (found in sour milk and tomato juice), etc.