TYROSINE IODINASE

Abstract

The synthesis of organically bound iodine by cell-free preparations of thyroid tissue has recently been achieved by Weiss (1).He has demonstrated that cell-free homogenates of thyroid tissue will incorporate iodine into organically bound form if they are supplemented with cupric ion and tyrosine.This synthesis has been shown by Fawcett and Kirkwood (2) to consist entirely of the formation of free monoiodotyrosine and is the result of the action of an enzyme tyrosine iodinase.The enzyme catalyzes the reaction of tyrosine with elemental iodine to form monoiodotyrosine.It is the purpose of this paper to report the occurrence and properties of this enzyme and to discuss its probable function.