Studies on the iodination of LH-RH and the biological and immunological activities of the products

Synthetic LH-RH was iodinated by the modified chloramine-T or lactoperoxidase method, using ¹²⁷INa or ¹²⁵INa. The yields of the products, the LH releasing activities of the monoiodinated peptides as well as binding to pituitary membrane fractions were measured. The variation in yield in the four procedures used for iodination was a function of the amount of oxidizing agent. Monoiodinated products obtained by the different procedures possessed comparable LH-releasing activities as well as binding affinity to pituitary plasma membranes.