Physicochemical study of the elctrolytic incorporation of iodine into bovine growth Hormone (BGH)
| Autor: | R. Radicella, H. Kurcbart, S. Quiroga, S.M.V. De Giacomini, V.A. Ciscato, Ricardo A. Caro |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
chemistry.chemical_classification
Radiation Chromatography Iodide chemistry.chemical_element Halogenation Iodine Electrolysis Hydrolysate Iodine Radioisotopes Nuclear Energy and Engineering chemistry Growth Hormone Isotope Labeling Yield (chemistry) Enzymatic hydrolysis Animals Organic chemistry Cattle Radiology Nuclear Medicine and imaging Tyrosine Quantitative analysis (chemistry) |
| Zdroj: | The International Journal of Applied Radiation and Isotopes. 25:497-500 |
| ISSN: | 0020-708X |
| DOI: | 10.1016/0020-708x(74)90075-1 |
| Popis: | The mechanism of iodination of the Bovine Growth Hormone (BGH) by means of the electrolytic method (at pH 7·4) was studied as a function of time and of total iodide to protein ratios. The yield of each labelling process was determined by paper electrophoresis. From these values and the respective iodide to protein molar ratios, the iodination degrees were calculated; frequently, iodination degrees higher than 12 (the maximum theoretically possible), were obtained. When the enzymatic hydrolysis of the samples was carried out, an increase of free iodide was observed, which was more significant at high iodide to protein molar ratios. The quantitative analysis of the chromatograms of the hydrolysates, allowed us to determine the relative amount of monoiodinated tyrosine residues (MIT) and diiodinated tyrosine residues (DIT) for different iodination degrees. It could be shown that for iodination degree of 12, only a 70 per cent of the radioactivity appeared as DIT. The calculation of the relative iodination degree for each molar ratio of iodide to protein, demonstrated that only a 75 per cent of the total available sites at the tyrosine residues admits the incorporation of iodine. Thus, it can be deduced that not all the tyrosine residues are equally accessible for the iodine atom. |
| Databáze: | OpenAIRE |
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