Iodoacetamide Alkyne-C3

Iodoacetamide Alkyne-C3 is suitable for use in isotopic tagging strategies for quantitative cysteine-reactivity profiling in various biological samples.

Iodoacetamide alkyne-C3 (IPM, IAA-C3, IA-alkyne-C3, IAM-alkyne-C3) is a bifunctional, thiol-reactive probe engineered for activity-based protein profiling (ABPP) of reactive cysteine residues in live cells, tissue homogenates, and tissues. This probe combines an iodoacetamide group, functioning as a covalent warhead for selective cysteine labeling, with a C3 alkyne moiety that acts as a click-chemistry handle. This alkyne allows for the subsequent conjugation of fluorophores or biotin-linked azido reporters, facilitating either the visualization or enrichment of labeled proteins. The IAA-C3 probe, the gold standard in the cysteinomics field, facilitates site-specific analysis of cysteine accessibility, reactivity, redox modification status, and covalent engagement in biological samples by allowing researchers to treat cell homogenates with varying concentrations of IA-alkyne C3, identifying highly reactive cysteines-such as those in enzyme active sites or redox-sensitive regions-that remain reactive despite dilution effects.