As maleimides, iodoacetamides are also among the most frequently used reagents for thiol modification. 5-IAF is one of the most popular fluorescent dyes for thiol modifications of proteins.
Baty JW, et al. (2002). Detection of oxidant sensitive thiol proteins by fluorescence labeling and two-dimensional electrophoresis. Proteomics 2, 1261-6; Moens PD, et al. (1994). Determination of the radial coordinate of Cys-374 in F-actin using fluorescence resonance energy transfer spectroscopy: effect of phalloidin on polymer assembly. Biochemitry 33, 13102-8.