Protein digestion, peptide mass and peptide fragmentation with MZCal: A user-friendly phone-compatible application

MZCal is a user-friendly, mobile-compatible web application designed for assisting peptide analysis in bottom-up mass spectrometry (MS). There are many tools for basic in-silico digestion, peptide mass and peptide mz calculations, though not in a single, convenient and mobile-friendly format. Since internet availability can often be limited on mass-spectrometry linked computers, we developed MZCal for use in our laboratory, featuring tools that we commonly use in evaluating MS methods for bottom-up proteomics while working at the mass spectrometer. MZCal provides a single platform for in silico protein digestion, peptide mass and fragmentation calculations, and spectral prediction using MS2PIP. Optimised for use on both Android and iOS devices, MZCal enables convenient, real-time mass spectrum interpretation in laboratory settings and as a teaching resource. Unlike more complex web-tools, MZCal offers a streamlined interface that prioritises ease of use and accessibility. Overall, MZCal serves as a practical, portable solution for essential peptide calculations, providing an intuitive and accessible tool for both researchers and educators.