Help Topics

Site Structure

The site consists of the information on all known bioactive peptides and precursor proteins in UniProt as well as peptide motifs. It enables users to perform rapid search via key features of peptides, to carry out statistical analysis on all these peptides and precursor proteins, to submit their peptide data, and to predict whether a given new protein sequence is a putative peptide or precursor protein (in progress). The site also provides links to UniProt protein database. This interface begins with a Main page, which includes Home, Search, Statistics, Submission, Help, Contact pages.

Fig.1 illustrates the architecture of the database site.

peptide site architecture Fig. 1

Home Page

Gives a general introduction on this database and its release version.

Search Page

Provides a rapid search for peptide records according to the following specific characteristics of peptides.

Peptide accession number

Each peptide accession number (database entry) in the peptide database is tagged by a unique accession number, beginning with characters ‘PEP’ followed by 5 numerical digits.

Peptide name

The full or partial name of the peptide.


Common English name for the organism. Users can choose the organism’s name from the pull-down menu.


The length of the peptide sequence, including minimum and maximum values (where applicable).

Monoisotopic mass

The monoisotopic mass of a peptide, including minimum and maximum values where applicable.

Peptide family

The name of the peptide family. Users can choose the peptide family from the pull-down menu. The peptide families are classified into ‘Growth factor and Cytokine’, ‘Neuropeptides and Peptide Hormones’, ‘Antimicrobial’, ‘Toxin’, ‘Antifreeze’, ‘Other families’ and ‘Unique peptides’. Each family in ‘Growth factor and Cytokine’, ‘Neuropeptides and Peptide Hormones’, ‘Antimicrobial’, ‘Toxin’, ‘Antifreeze’ or ‘Other families’ contains at least two peptides or precursor proteins. Proteins in ‘Unique peptides’ have no significant similarities to any above-mentioned family proteins.

Uniprot accession number (n)

Protein accession number in UniProt. The number between brackets indicates the frequency of the peptide sequence within its precursor protein. By default, n is equal to 1.

Amino acid sequence

The entire amino acid sequence of a peptide. Maximum is 1000 amino acids.


The peptide is obtained from either of the two sources: Uniprot and EROP-Moscow. By default, a peptide is annotated in Uniprot.

Statistics Page

Contains a list of statistics on length distribution, species distribution and family distribution of all peptides and precursor proteins.

Submission Page

Provides a window where users can submit their peptide data to this database.

Help Page

Provides information on how to use this site.

Contact Page

Directs users to our e-mail address.