Identification of Mono-iodotyrosine from Iodinated Pepsin
نویسنده
چکیده
Isolation of mono-iodotyrosine from slightly iodinated pepsin has been repeated and the properties of the product compared with those of synthetic dl-3-iodotyrosine. Ultraviolet absorption spectra, pK values of the phenol group, solubility measurements, and partition coefficients were so nearly identical for the two materials that there is now no reason to doubt that the product from pepsin is 3-iodotyrosine.
منابع مشابه
Identification of Mono-iodotyros1ne from Iodinated Pepsin By
In an earlier paper (1) the writer reported the isolation of/-mono-iodotyrosine from an alkaline hydrolysate of very slightly iodinated pepsin. Since then Harington and Pitt Rivers (2) have synthesized/-mono-iodotyrosine and dlmono-iodotyrosine and a comparison of the properties of their compounds with those reported by us led them to conclude that for the compound from pepsin "the nature remai...
متن کاملInactivation of Pepsin by Iodine
1. Pepsin solutions were iodinated at pH 5.0-6.0 until 10-20 per cent of the activity was lost and 1/20 (0.7 per cent) of the saturating amount of iodine had been introduced into the protein molecule. After alkaline hydrolysis 65 per cent of the original iodine was accounted for as mono-iodotyrosine although only 42 per cent was isolated as a crystalline product. No evidence was obtained to sup...
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A method is described for the determination of serum thyroxine using ion-exchange resin sponges. The principle is based on the use of protein-binding sites and part of the technique is similar to the Triomet resin uptake test. An isotope extraction recovery procedure is incorporated in the method. Studies of factors influencing the analysis are reported and the results of tests of accuracy, pre...
متن کاملInactivation of Pepsin by Iodine and the Isolation of Diiodo-tyrosine from Iodinated Pepsin
In the presence of iodine at pH 5.0-6.0 a solution of pepsin absorbs iodine and the specific proteolytic activity of the solution decreases. The activity is less than 1 per cent of the original activity when the number of iodine atoms per mol of pepsin is 35-40. If the pH is 4.5 or less, iodine reacts very slowly and there is a correspondingly slower loss in activity. Glycyl tyrosine reacts wit...
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In normal conditions, serum (or plasma) iodine is largely composed of thyroxine and iodide with small quantities of thyroactive iodothyronines, such as 3: 5: 3'-tri-iodothyronine and 3: 3'-di-iodothyronine (Gross and Pitt-Rivers, 1952; Roche, Lissitzky, and Michel, 1952a and b; Roche, Michel, Nunez, and Wolf, 1956). Another relatively less active compound, 3: 3': 5'-tri-iodothyronine, is presen...
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ورودعنوان ژورنال:
- The Journal of General Physiology
دوره 31 شماره
صفحات -
تاریخ انتشار 1947