Hydrophobic / Hydrophilic
Also known as: hydrophobic · hydrophilic · solubility · water solubility
Whether a peptide (or its parts) is attracted to water or repelled by it — a key driver of solubility and folding.
Hydrophilic ("water-loving") parts of a peptide mix readily with water; hydrophobic ("water-fearing") parts avoid it and cluster together. Each amino-acid side chain sits somewhere on this scale.
The balance governs how easily a peptide reconstitutes and stays in solution, and it drives folding — hydrophobic residues tend to bury themselves away from water. A very hydrophobic peptide may need a co-solvent before it will dissolve in aqueous buffer.
RELATED TERMS
Side Chain (R Group)
The variable "R group" on each amino acid that gives it its chemical character — charge, size and water-affinity.
Reconstitution
The process of dissolving a lyophilised (freeze-dried) peptide in a sterile solvent such as bacteriostatic water before study.
Isoelectric Point (pI)
The pH at which a peptide carries no net charge — where it is least soluble, affecting handling and purification.
Secondary & Tertiary Structure
The levels of peptide/protein organisation: sequence (primary), local folds (secondary), 3-D shape (tertiary), assembly (quaternary).
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.