iodotyrosine

An iodated derivative of L-tyrosine. This is an early precursor to L-thyroxine, one of the primary thyroid hormones. Iodotyrosine is made from tyrosine via thyroid peroxidase and then further iodinated by this enzyme to make the di-iodo an tri-iodo variants. Two molecules of di-iodotyrosine combine to form T4, and one molecule of mono-iodotyrosine combines with one molecule of di-iodotyrosine to form T3.