Sentence:  The <WSD>protein</WSD> bound iodine was 6.6 | mg. % , and the radioactive iodine uptake over the thyroid gland was 46 % in 24 hours , with a conversion ratio of 12 % . 
Meaning of the word marked with <WSD> tags:  any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes