"A porcine thyroid enzyme was extracted from thyroid tissue by homogenization and differential centrifugation. The enzyme was capable of metabolizing both 3-iodotyrosine and 3,5-diiodotyrosine. All of the thyroid subcellular particles produced a fluorescent compound when incubated with these substrates. When the 1,000 x g sediment was supplemented with the 48,000 x g supernatant a second compound was formed. The compound was UV absorbing and has been identified as either 3-iodo-4-hydroxybenzaldehyde or 3,5-diiodo-4-hydroxybenzaldehyde depending upon which substrate was used. The 1,000 x g sediment was solubilized with 1% Conoco 1012-6 detergent. The activating factor in the 48,000 x g supernatant was shown to be a macromolecule, probably a protein, by dialysis and ammonium sulfate precipitation. The enzymes in both fractions are required to form 3-iodo-4-hydroxybenzaldehyde. Conversion of the reaction products to their dinitrophenylhydrazones followed by paper chromatography indicated that the benzaldehydes were formed by decomposition of the corresponding p-hydroxyphenylpyruvic acid. This rules out the enzymatic formation of the benzaldehydes. This study lends support to model system studies which have suggested that 3,5 diiodo-4- hydroxyphenylpyruvic acid should be an intermediate in the formation of thyroxine"--Abstract, Page ii.
Nicholson, Larry M.
Siehr, Donald J.
Wixson, Bobby G.
M.S. in Chemistry
University of Missouri--Rolla. Department of Chemistry
University of Missouri--Rolla
ix, 74 Pages
© 1970 Shih-ying Sun, All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Tyrosine in the body
Thyroid gland -- Research
Print OCLC #
Electronic OCLC #
Link to Catalog Recordhttp://laurel.lso.missouri.edu/record=b1067206~S5
Sun, Shih-ying, "Metabolism of 3-iodotyrosine and 3,5-diiodotyrosine by thyroid extracts" (1970). Masters Theses. 7056.