About isodist

isodist is a program which uses Fourier transform convolution to calculate the isotope distribution of peptide and nucleic acid species with complex labeling patterns, and least squares to fit the calculated distribution to a data set.

Features

• Supports simultaneous calculation of isotope distributions for mixtures containing an arbitrary number of species (e.g. Unlabeled + 20% ¹⁵N labeled + 40% ¹⁵N labeled + 60% ¹⁵N labeled + 80% ¹⁵N labeled)
• Supports labeling based on elements (e.g. ¹⁵N labeling of the entire peptide) or residues (e.g. ¹³C Leucine labeling)
• Incorporates a least squares fitting routine to determine both the extent of labeling for the defined labeling pattern for a given species, and the relative amounts of different species in a mixture
• Automatically corrects for peak width, a machine-based mass offset and non-zero baseline
• Can be run in batch mode to quickly fit hundreds or thousands of different aquired spectra

Please cite the following paper when referencing isodist

Edit Sperling, Anne E. Bunner, Michael T. Sykes and James R. Williamson. Quantitative Analysis of Isotope Distributions in Proteomic Mass Spectrometry Using Least-Squares Fourier Transform Convolution. Analytical Chemistry, 80, pp. 4906-4917 (2008).