Spatial requirement for coupling of iodotyrosine residues to form thyroid hormones.

Abstract
A linear random copolymer of tyrosine and lysine and 2 synthetic oligopeptides containing 2 tyrosine residues in addition to lysine residues give thyroid hormone (thyroxine and triodothyronine) residues in good yield on enzymatic iodination with thyroid peroxidase. These synthetic peptides may serve as simple models for thyroglobulin, the protein in which biosynthesis of the thyroid hormone takes place. For the formation of significant amounts of hormone, such model compounds must contain at least 2 properly spaced tyrosine residues.