Thermo Scientific Pierce Iodoacetic Acid (IAA) reacts with many protein functional groups but is typically used for sulfhydryl groups (reduced cysteine acid)-specific S-carboxymethylation.

Pierce Characteristics of iodoacetic acid (IAA):

• Reacts at slightly alkaline pH conditions for specific S-carboxymethylation of free sulfhydryl groups
• Reacts at methionine Reacts at low pH for specific carboxymethylation
• Reacts at high pH to support carboxymethylation of histidine and lysine
• Enables reducing cysteine in protease digestion Methylation of amino acid peptide fragments for mass spectrometry analysis

Iodoacetic acid interacts with the sulfhydryl group on cysteine, the imidazolyl side chain nitrogen of histidine, the thioether of methionine and the primary amine of lysine group reaction. The reaction rate and specificity depend on the ionization level, which can be manipulated by the pH of the reaction conditions.

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Pierce™ Iodoacetamide (single Use)