A versatile procedure for the radioiodination of proteins and labeling reagents.

For tracer or analytical studies it is often useful to label proteins by direct iodination or by reacting them with an iodinated reagent. A simple iodination technique with hydrogen peroxide is described for use with either carrier-free or low-specific-activity iodine. The method introduces less oxidative damage to proteins than any other procedure tested, yet the efficiency of labeling approaches that offered by the chloramine T or Iodogen methods. The method has been applied to the facile and inexpensive preparation of the iodinated Bolton-Hunter reagent. This peroxide iodination procedure should be particularly useful for labeling proteins or peptides for structural investigations or for immunoassays.