A field guide to scientific language
One-Letter Peptide Sequence and Composition Reader
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Sequence and composition reader
Paste a sequence written in the 20 standard one-letter amino acid codes. Spaces, line breaks and lowercase letters are accepted.
Enter a sequence to see its residue count and composition.
Read how to transcribe terminal groups and sequence annotations.
| Input | Expected result |
|---|---|
GAS | 3 residues, one each of glycine (G), alanine (A) and serine (S). |
g a s, including line breaks | Same composition. Lowercase and whitespace are accepted. |
Ac–GAS–NH₂ | The reader stops at the annotation. Transcribe the N-acetyl and C-amide groups separately in the guide. |
Composition counts the letters you entered. The sequence alone cannot establish the identity of a physical sample or predict its activity.