TURBOLYTIK: a peptide cleavage program for personal computers

A microcomputer program that simulates the cleavage of polypeptides by various chemical and enzymic means is described. The program is written in Turbo Basic, a new dialect of Basic, and is compiled to run on personal computers using the MS-DOS operating system. The program generates all the possible cleavage fragments that can arise when a protein of known primary structure is cleaved at susceptible sites. The output also provides the estimation of the molecular weights, the charge per molecule at a given pH and a prediction of the isoelectric point. The program is designed to facilitate the easy selection of suitable proteolytic methods in protein chemistry, identification of peptides on a peptide map generated by conventional means or in mass spectra obtained from mass spectrometry. The program will find use in laboratories attempting to define posttranslational covalent modifications on protein molecules or exclude frame-shift errors in the deductions of primary structures from cDNA clones.