title: A simplified calculation procedure for mass isotopomer distribution analysis (MIDA) based on multiple linear regression.
abstract: We have developed a novel, rapid and easy calculation procedure for Mass Isotopomer Distribution Analysis based on multiple linear regression which allows the simultaneous calculation of the precursor pool enrichment and the fraction of newly synthesized labelled proteins (fractional synthesis) using linear algebra. To test this approach, we used the peptide RGGGLK as a model tryptic peptide containing three subunits of glycine. We selected glycine labelled in two13C atoms (13C2-glycine) as labelled amino acid to demonstrate that spectral overlap is not a problem in the proposed methodology. The developed methodology was tested first in vitro by changing the precursor pool enrichment from 10 to 40% of13C2-glycine. Secondly, a simulated in vivo synthesis of proteins was designed by combining the natural abundance RGGGLK peptide and 10 or 20%13C2-glycine at 1 : 1, 1 : 3 and 3 : 1 ratios. Precursor pool enrichments and fractional synthesis values were calculated with satisfactory precision and accuracy using a simple spreadsheet. This novel approach can provide a relatively rapid and easy means to measure protein turnover based on stable isotope tracers. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Physical and Analytical Chemistry Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006, Oviedo, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Fernández-Fernández
authors.affiliation: Department of Physical and Analytical Chemistry Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006, Oviedo, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-González
authors.affiliation: Department of Physical and Analytical Chemistry Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006, Oviedo, Spain. jiga@uniovi.es.
authors.forename: J Ignacio
authors.identifier: http://orcid.org/0000-0002-8356-3866
authors.initials: JI
authors.lastname: García Alonso
mesh_terms: D000595:Amino Acid Sequence; D002247:Carbon Isotopes; D002851:Chromatography, High Pressure Liquid; D005998:Glycine / Q000737:chemistry; D016014:Linear Models; D013058:Mass Spectrometry / Q000379:methods*; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D009842:Oligopeptides; C000626708:RGGGLK peptide; D005998:Glycine
keywords: LC-MS; glycine; mass isotopomer distribution analysis; multiple linear regression; peptides