Cyclic Peptides Sequencing

Welcome to the Cyclic Peptide Sequencing home page. In here, we make available a series of tools to help analyze mass spectrometry data from cyclic peptides. Although the motivation for our tools is to characterize Nonribosomal Peptides (NRPs) with a cyclic backbone, these algorithms are applicable to ribosomal cyclic peptides. This research project is described in our paper [Ng et al. Dereplication and de novo sequencing of nonribosomal peptides Nature Methods 2009].

NRP-Annotation

This tool can be used to annotate a spectrum from a cyclic peptide. The sequence of masses must be provided as an input for the tool.

NRP-Dereplication

This is a mutation tolerant database search tool for cyclic peptides. The current version uses all cyclic peptides found on the Norine database. Additional sequences can be added manually.

NRP-Tagging

This tool will attempt to reconstruct the cyclic peptide from the mass spectrum in an amino-acid-alphabet-free mode. In contrast to de novo sequencing tools for linear peptides (where typically 20 standard masses are considered), all possible mass values are considered during the reconstruction of the cyclic by NRP-Tagging.

Help

Please check out the tutorials in the documentation section for sample runs of our software.

Collaborations

This project was made possible with the help of our collaborators: If you have cyclic peptide libraries and don't mind sharing with us, we are happy to set up a collaboration with your group. You can find more information about our group and my pricipal investigator on the web. Contact information for specific inquiries about the webtools on this website can be found here.