## 2 Database Description
Profiles of potential biological activity of protein fragments may be sorted according to activity (this version has been available since the launching of the parent database of bioactive peptides) or by fragment sequence. The second option has been added to follow the remarks of users interested in multifunctional peptides. Another modification was the replacement of the \"aromatic\" version of SMILES representations of aromatic amino acids (fulfilling formal aromaticity rule) by the Kekule version according to recent recommendations [21; 22]. For instance, SMILES strings N[C@@H](C1c1[nH]cn1)C(=O)O and N[C@H](C1c1[nH]2c1 ccccc2)C(=O)O were replaced by N[C@H](CC1=CN=C[NH]1)C(=O)O and N[C@H](CC1=C[NH]C2=CC=CC=C12)C(=O)O for histidine and tryptophan, respectively. Aromatic SMILES representations of compounds containing heterocyclic (e.g., histidine) and/or conjugated (e.g., tryptophan) aromatic rings are sometimes not accepted by molecular editors or search engines of chemical databases. The PubChem search engine, the biggest database of chemical compounds, converts SMILES representations from the aromatic to the Kekule version [21]. The change of SMILES representations was expected to improve the interoperability of the BIOPEP-UWM with chemical databases and programs from the approach of cheminformatics. Apart from existing links to bioinformatic tools [12], a new tab has been added that provides access to free access programs for molecular docking, available via the web servers and not requiring downloading and installation on users' computers (labelled \"2\" in Figure 1). A screenshot of part of the content of this tab is presented in Figure 5. Information concerning the program includes the name, website, and reference describing the program. Programs are placed on the website in alphabetical order. The first three are shown in Figure 6. Links to some of these programs are also available via the \"Useful links\" tab (Figure 1) (category: \"Bioactivity prediction\") and via the MetaComBio website [23] tab named \"Programs\". The last website also possesses the following new address: [[https://biochemia.uwm.edu.pl/metachemibio/about-metacombio/](https://biochemia.uwm.edu.pl/metachemibio/about-metacombio/)]([https://biochemia.uwm.edu.pl/metachemibio/about-metacombio/](https://biochemia.uwm.edu.pl/metachemibio/about-metacombio/)) (Last accessed on 13 July 2022). We would like to encourage users to submit new information about virtual bioactive peptides to the new database. The above sentence concerns both new peptide sequences, additional information about existing compounds, and correction of errors, if necessary. Although the database's task is to mainly annotate peptides of food origin, submissions of peptides from other sources, synthetic or even in silico, will be accepted as well. The prediction method will be not restricted to molecular docking. Other methods, such as the quantitative structure\(-\)activity relationship (QSAR) or machine learning, can also be included. The BIOPEP-UWM database annotates peptides consisting of proteinogenic amino acids and their D-enantiomers. Sequences should be written in a single letter code. The submission form of new peptide sequences is available on the database homepage (Figure 1) below the tab of the BIOPEP-UWM Virtual database. The submitted information should include the peptide sequence, sender e-mail address for correspondence, name and surname, and full bibliographic data of the article describing a given peptide. We only take into account peptides described in peer-reviewed publications.