thyroprotein

noun

thy·​ro·​pro·​tein ˌthī-rō-ˈprō-ˌtēn, -ˈprōt-ē-ən 

: any of various preparations made by iodinating proteins and having physiological activity similar to that of thyroxine and related iodinated protein constituents from the thyroid gland

especially : iodinated casein compare iodoprotein