A simple method for monitoring the cysteine content in synthetic peptides

J Pept Sci. 2008 Jul;14(7):838-44. doi: 10.1002/psc.1012.

Abstract

A new method for the determination of the cysteine content of synthetic peptides is described. For this purpose the classical amino acid analysis is not suitable, as cysteine may undergo oxidative dimerisation to cystine during the hydrolysis or evaporation. The intact peptide was reacted with N-ethylmaleimide (NEM) yielding a stable S-(N-ethylsuccinimido)-cysteine derivative, which could be separated by RP-HPLC and characterised by mass spectrometry. For the quantitative determination less than 0.1 microM peptide was sufficient.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chromatography, High Pressure Liquid / methods*
  • Cysteine / analysis*
  • Cysteine / chemistry
  • Mass Spectrometry / methods*
  • Models, Biological*
  • Models, Molecular
  • Molecular Structure
  • Peptides / analysis*
  • Peptides / chemistry*

Substances

  • Peptides
  • Cysteine