Determination of the empirical formula of peptides by fast atom bombardment mass spectrometry

Abstract

A method for calculating the empirical formulae of peptides from mass spectrometric data is described. Exact mass measurement data and isotopic peak ratios are used to generate a list of potential empirical formulae that fit a given compound within experimental error. The formulae are then analysed by a mathematical algorithm and only those corresponding to chain peptides formed from the basic amino acids are retained. Calculations conducted for typical peptides indicate that the approach may be useful for peptide identification if the experimental values are determined within an acceptable range of errors. Experimental measurements of the exact mass and isotopic peak ratios made using typical peptides demonstrate the feasibility of the approach.

A Fast and Simple Algorithm for the Money Changing Problem

“…From the residue table, or from the last column of the extended residue table, we can see that the Frobenius number for this example is g (5,8,9,12…”

“…From the application side, the problem of finding molecules with a given mass was addressed frequently from the biochemical and MS viewpoint, see for instance [5], [12], [23], and [27].…”

Decomp—from interpreting Mass Spectrometry peaks to solving the Money Changing Problem

“…A considerable amount of biochemical and mass spectrometry literature exists on the problem of determining the sum formula of a sample molecule from its mass, see for instance (Bertrand et al, 1987;Fu¨rst et al, 1989;Pomerantz et al, 1993), and there are approaches that use known sum formulas for interpreting a mass spectrum (Grange et al, 2006;Kind and Fiehn, 2006;Spengler, 2004). There exist software packages to compute these sum formulas, for example Seth (http://www.zebra-crossing.de/ software/), ElComp (http://medlib.med.utah.edu/masspec/), HiRes MS (http://homepage.sunrise.ch/mysunrise/joerg.hau/ sci/), Elemental Composition Calculator (http://www.wsearch.…”