On April 15, 2021, Murphy, EmmaRae L.; Joy, Andrew P.; Ouellette, Rodney J.; Barnett, David A. published an article.Formula: C2H4ClNO The title of the article was Optimization of cysteine residue alkylation using an on-line LC-MS strategy: Benefits of using a cocktail of haloacetamide reagents. And the article contained the following:
Several common reagents for the alkylation of cysteine residues of model intact proteins were evaluated for reaction speed, yield of alkylated product and degree of over-alkylation using an online LC-MS platform. The efficiency of the alkylation reaction is found to be dependent on the (1) reagent, (2) peptide/protein, (3) reagent concentration and (4) reaction time. At high reagent concentrations, iodoacetic acid was found to produce significant levels of over-alkylation products wherein methionine residues become modified. For optimal performance of the alkylation reaction, we found the use of a cocktail of chloroacetamide, bromoacetamide and iodoacetamide worked best. The alkylating efficiency of each haloacetamide is a balance between the characteristics of the halogen leaving group and the steric hindrance of the alkylation site on the peptide or protein. A key aspect of using a cocktail of haloacetamides is that they all produce the same modification (+57.0209 Da) to the cysteine residues of the protein while the alkylation efficiency of each site may differ for each of the three reagents. Over-alkylation effects appear to be lower with the cocktail due to a lower concentration of each reagent. The haloacetamide cocktail could be useful when considering complex mixtures of proteins. The experimental process involved the reaction of 2-Chloroacetamide(cas: 79-07-2).Formula: C2H4ClNO
The Article related to alkylation, kinetics, liquid chromatography and quadrupole-orbitrap mass spectrometer, protein, acetamides: chemistry, alkylation, chromatography, liquid, cysteine: chemistry, iodoacetamide: chemistry, proteins: chemistry, tandem mass spectrometry and other aspects.Formula: C2H4ClNO
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics