An isotope coding strategy for proteomics involving both amine and carboxyl group labeling.
This paper describes a heavy isotope coding strategy for the analysis of all types of tryptic peptides, including those that are N-terminally blocked and from the C-terminus of proteins. The method exploits differential derivatization of amine and carboxyl groups generated during proteolysis as a means of coding. Carboxyl groups produced during proteolysis incorporate 18O from H218O. Peptides from the C-terminus of proteins were not labeled with 18O unless they contained a basic C-terminal amino acid. Primary amines from control and experimental samples were differentially acylated after proteolysis with either 1H3- or 2H3-N-acetoxysuccinamide. When these two types of labeling were combined, unique coding patterns were achieved for peptides arising from the C-termini and blocked N-termini of proteins. This method was used to (1) distinguish C-terminal peptides in model proteins, (2) recognize N-terminal peptides from proteins in which the amino terminus is acylated, and (3) identify primary structure variations between proteins from different sources.
Liu
Peiran
P
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
Regnier
Fred E
FE
D000588:Amines / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002645:Chickens; D002845:Chromatography; D013058:Mass Spectrometry; D009154:Mutation; D010103:Oxygen Isotopes / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D000588:Amines; D010103:Oxygen Isotopes; D010455:Peptides; D011506:Proteins; D020543:Proteome