Iodine-125-human serum albumin

Hughes, W.L., and Straessle, R. (1950) Preparation and properties of serum and plasma proteins. XXIV. Iodination of human serum albumin./. Am. Chem. Soc. 72, 452-457. 

Phenols and phenol ethers are very good substrates for haloperoxidases. The first aromatic substrate to be used in enzymatic iodination was tyrosine. This substrate was iodinated using chloroperoxidase from Caldariomyces Jumago1441 and thyroid peroxidase1451. Horseradish peroxidase and lactoperoxidase have been used to lable proteins with radioactive isotopes of iodide111 and bromoperoxidase from Penicillus capitatus has been employed to lable human serum albumin with the radioactive isotope of bromine1461. 

Tatum JL, Burke TS, Hirsch JI et al (1983) Pitfall to modified in vivo method of technetium-99m red blood cell labeling - iodinated contrast media. Clin J Nucl Med 8 585-587 Thrall JH, Freitas JE, Swanson D, Rogers WL, Clare JM, Brown ML, Pitt B (1978) Clinical comparison of cardiac blood pool visualization with technetium 99m red blood cells labeled in vivo and with technetium 99m human serum albumin. J Nucl Med 19 796-803 United States Pharmacopeial Convention (2005) Official Monographs USP 28, technetimn Tc 99m pyrophosphate injection. United States Pharmacopeia (USP) 28-national formulary (NF) 23, p 1862... 

S1I -labelled form, iodinaled (,lll) human serum albumin, J,f HSA, Albumotope u,f, Macroscan-131, Risa-I31-H. Normal human serum albumin mildly jodinated with radio-active iodine (1311) which has a half-life of 8 days, and emits beta and gamma rays. Contains not more than one atom of iodine par molecule of albumin (mol wt 60,000). Physical and chemical proparties essentially the same as those of albumin. Stable at 10° for at least 3 weeks. Supplied for injection in aq isotonic sodium chloride soln. 

Radioiodide has also been separated from iodine-labeled proteins (human serum albumin and Bovine IgG) by thin-layer gel filtration on Sephadex G-200 and G-75 superfine layers (163). (Sephadex is a modified dextran.) The protein solutions were applied in amounts of 5-10 vJL to the Sephadex layers and the angle of slope of the layers was 15°. Elution was carried out with 0.2 M Tris buffer (Tris = tris (hydroxymethyl) aminomethane) at pH 8.0. The buffer contained Tween 80. Separations took 45-60 min on Sephadex G-75 and 3-4 h on Sephadex G-200 and were particularly good on the latter. 

Serum albumin labeled with an iodine radionuclide was firstly used as a substrate for determining protease activity by Absolon This method was later on modified several times and applied for assaying various proteolytic activities in different materials. Mego et al. injected denaturated I-human %rum albumin into the tail vein of rats and measured the rate of intralysosomal proteolysis on isolated lysosomes containing endocytosed substrate. This method was also used for the determining the intralysosomal pH on the basis of differences found in the rate of I-albumin breakdown in intact and lysed lysosomes C-bovine serum albumin, I-casein or I-albumin have been alternatively used as substrate for measuring the activity of trypsin, chymotrypsin and papain - ). 

T4), monoiodotyrosine (MIT), and diiodotyrosine (DIT). The orthodox view states that the iodothyronines, namely T3 and T4, account for all the organic iodine in normal human serum (P9, Wll). However, there are claims that the iodotyrosines, MIT and DIT, also occur in significant amounts in the serum (D5), but if this is true, then they are strongly associated with, or bound to, serum albumin and are not subject to the rapid clearance known for free serum iodotyrosines (W4). 

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