Serum albumin

About: Serum albumin is a research topic. Over the lifetime, 16337 publications have been published within this topic receiving 516395 citations. The topic is also known as: blood albumin & ANALBA.

Aflatoxin-albumin adducts in human sera from different regions of the world.

Abstract: An immunoassay now permits the determination of human exposure to aflatoxin at an individual level and consequently allows a better assessment of the role of aflatoxin, and its interaction with hepatitis B virus infection, in the aetiology of liver cancer. Measurements of aflatoxin bound to serum albumin in children and adults from various African countries show that between 12 and 100% contain aflatoxin-albumin adducts, with levels up to 350 pg AFB1-lysine equivalent/mg albumin. In Thailand, lower levels and prevalence of this adduct were observed, while no positive sera were detected from France or Poland. Data are presented showing that exposure to this carcinogen can occur throughout life and the relevance of these observations to the understanding of the multifactorial aetiology of liver cancer in these countries is discussed.

Renal tubular uptake of protein: effect of molecular charge

Abstract: The effect of molecular charge of proteins on proximal tubular reabsorption was evaluated in the rat. Native and two cationized forms of albumin, native and anionized lysozyme, and native and anionized cytochrome c were iodinated with 125I. The different forms of each type of protein were alternately microinfused into the same site of proximal convoluted tubules in vivo. Tubular reabsorption was determined as the difference between the amounts of TCA-precipitable radioactivity infused and recovered in the urine. At low concentration of albumin 5 times more cationized than anionic albumin and 2.7 times more cationic than anionized lysozyme were reabsorbed by the proximal tubule. At two of four concentrations, proximal tubular uptake of cationic cytochrome c exceeded that of anionized cytochrome c. Uptake of cationic cytochrome c exceeded that of cationic lysozyme; however, the difference in uptake between native cationic and anionized species of the two proteins was much greater for lysozyme than for cytochrome c. The data reveal that a higher isoelectric point significantly enhances proximal tubular reabsorption of albumin, lysozyme, and cytochrome c and that proteins with similar molecular weight and isoelectric point are not necessarily reabsorbed to the same degree. This suggests that in addition to total molecular charge the molecular configuration and/or distribution of electrical charges on teh protein surface determine protein binding by the luminal membrane and subsequent endocytosis by the proximal tubule.

Isoelectric focusing of proteins in the native and denatured states. Anomalous behaviour of plasma albumin

Abstract: 1. An analytical technique of isoelectric focusing in thin layers of polyacrylamide gel has been used to determine the isoelectric point, pI, of several proteins in the presence and in the absence of concentrated urea. 2. The presence of urea did not greatly affect pI except for bovine plasma albumin, where an increase of approx. 1pH unit was found. 3. Evidence is presented that this change in the pI of bovine plasma albumin is due to the normalization of certain ionizable groups on unfolding of the protein in urea. 4. Evidence is also presented that prolonged exposure of bovine plasma albumin to urea results in intramolecular disulphide interchange and that, on removal of urea, the new patterns of disulphide bonding stabilize abnormal conformations with pI values intermediate between those of the native and denatured states. 5. The studies demonstrate heterogeneity in bovine plasma albumin based on primary-sequence differences. 6. Isoelectric focusing of proteins in urea appears to be useful in the study of various aspects of protein structure.