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Iodation enzymatique de protéines
Author(s) -
Nunez J.,
Pommier J.,
El Hilali M.,
Roche J.
Publication year - 1965
Publication title -
journal of labelled compounds
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0022-2135
DOI - 10.1002/jlcr.2590010206
Subject(s) - thyroglobulin , chemistry , enzyme , halogenation , iodide , biochemistry , ultracentrifuge , denaturation (fissile materials) , iodine , chromatography , organic chemistry , thyroid , nuclear chemistry , biology , endocrinology
An iodination enzymatic method has been studied which makes possible the preparation of 125 I or 131 I labelled proteins. Iodide oxidation is catalyzed by horse‐radish peroxydase; H 2 O 2 is furnished by another enzymatic system: glucose‐glucose oxydase. We have studied: 1) The optimal enzymatic iodination conditions for various proteins with different biological activities (immunological, hormonal, enzymatic). 2) The enzymatic iodination reaction mechanism. 3) Some molecular characteristics of the iodoproteins prepared.We have established that: 1) The iodide oxidation is catalized by the horse‐radish peroxydase and not directly caused by H 2 O 2 produced by the glucose‐glucose oxydase system. 2) When iodide atoms are introduced in a protein in the conditions defined above — serumalbumin or thyroglobulin, for instance — no apparent denaturation occurs; but a shift of the sedimentation coefficient established by sucrose gradient ultra‐centrifugation appears which may be due to a change of the proteins shape.These results has been discussed: 1) as to the validity of this method from a preparative point of view. 2) as a simple model of the physiological structural transitions observed during the biosynthesis and iodination of thyroglobulin.