Albumin iodinated

Trichloroethanoic acid, CCI3COOH. A crystalline solid which rapidly absorbs water vapour m.p. 58°C, b.p. 196-5" C. Manufactured by the action of chlorine on ethanoic acid at 160°C in the presence of red phosphorus, sulphur or iodine. It is decomposed into chloroform and carbon dioxide by boiling water. It is a much stronger acid than either the mono- or the dichloro-acids and has been used to extract alkaloids and ascorbic acid from plant and animal tissues. It is a precipitant for proteins and may be used to test for the presence of albumin in urine. The sodium salt is used as a selective weedkiller. 

Reported applications of SASD involve modification of lipopolysaccharide (LPS) molecules and studying their interaction with albumin and an antibody directed against LPS (Wollenweber and Morrison, 1985), identification of the murine interleukin-3 receptor and an N-formyl peptide receptor (Sorenson et al., 1986), crosslinking of factor V and Va to iodinated peptides... 

Purify the iodinated protein from excess reactants by gel filtration using a desalting resin. The column may be pre-treated by passing a solution of bovine serum albumin (BSA) through it to eliminate nonspecific binding sites that could cause significant protein loss in small-sample applications. 

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. 

Figure 3. Autoradiograph of radio-iodinated bovine serum albumin (BSA), adsorbed onto glass and subsequently immersed in phosphate-buffered saline for (from left to right) 0, 1, 2, 4, and 16 h. Reproduced from Michaeli et al. (7) with permission of Academic Press.

It is widely employed as a disinfectant in medicine (Povidone-iodine) because of its mildness, low toxicity, and water solubility. According to the U.S. Pharmacopeia, l ovidone-iodme is a free-flowing, brown powder dial contains from 9-12% available iodine. 11 is soluble in water and lower alcohols. When dissolved in water, the uncomplexed free iodine level is very low however, tine complexed iodine acts as a reservoir and by equilibrium replenishes the free iodine lo the equilibrium level. This prevents free iodine from being deactivated because the free form is continually available at effective biocidal levels from this large reservoir. PVP will interact with other small anions and resembles serum albumin and other proteins in this regard. It can be salted in with anions such as NaSC.N or out with NasSOa much like water-soluble proteins. 

Although aseptic meningitis has been associated with the use of radioactive iodine, the products used were albumin complexes (131I-RISA) this complication is almost certainly attributable to the protein content or to pyrogens rather than to the radioactive iodine itself (8). 

TABLE III. Intramuscular administration of albumin microspheres containing 131-iodine labeled rose bengal to rabbits (mean + sem) (n = 3)... 

N. Effing, F. Gehin-Fouque, Iodinated compounds and thyroxine binding to albumin in human breast milk, Pediatr. Res., 18(9) (1984), 901-903. 

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 - ). 

Bill et al. (1960) used Sephadex to remove excess iodide from iodinated albumin. A sample as small as 0.02 ml was added to the top of a 0.3 X 25-cm column. During the development in distilled water each effluent drop was assayed for radioactivity and protein. 

Bovine plasma albumin and dog serum albumin have been iodinated with di- I-labeled methyl p-hydroxybenzimidate. The authors did not attempt to obtain maximum specific activity, but rather examined the effect of reaction conditions on the rate of amidination and yield of iodinated product. The set of conditions given above is only one of the many tested. It was chosen because it gave the highest incorporation of I. Overall the results showed that the iodination reaction will proceed at pH 7.5-9.5 and... 

If a similar longitudinal section of a soaked grain be mounted in dilute iodine solution, the contents of the aleurone cells will be colored yellow indicating their proteid nature, while the starch grains will take on a blue to violet coloration. The endosperm will be observed taking up most of the room within the seed coat. The contents of its cells are not baled out to the embryo until after germination begins. Indian Corn is therefore an albuminous seed. 

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