Explorateur acides aminés & peptides

A pocket peptide calculator. Paste a one-letter sequence (or contiguous three-letter codes), press Analyze.

Charge vs pH. Every ionisable group — N-terminus, C-terminus, and acidic/basic side chains — contributes a Henderson–Hasselbalch term. The green mark is the isoelectric point (pI), where net charge crosses zero; the red mark follows the pH slider.

Mass. Average isotopic residue masses with one water removed per peptide bond.

Hydropathy. Kyte–Doolittle scores in a sliding window (default 9). Positive means hydrophobic — useful for spotting transmembrane stretches.

Limits. No disulfide pairing, no PTMs, no terminal modifications, no precise pKa shifts from neighbours. Side-chain types follow the usual textbook set (Asp, Glu, Cys, Tyr acidic; His, Lys, Arg basic).