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.

Two novel rat liver membrane proteins that bind advanced glycosylation endproducts: relationship to macrophage receptor for glucose-modified proteins.

Abstract: Advanced glycosylation endproducts (AGEs), the glucose-derived adducts that form nonenzymatically and accumulate on tissue proteins, are implicated in many chronic complications associated with diabetes and aging. We have previously described a monocyte/macrophage surface receptor system thought to coordinate AGE protein removal and tissue remodeling, and purified a corresponding 90-kD AGE-binding protein from the murine RAW 264.7 cell line. To identify AGE-binding proteins in normal animals, the tissue distribution of 125I-AGE rat serum albumin taken up from the blood was determined in rats in vivo. These uptake studies demonstrated that the liver was a major site of AGE protein sequestration. Using a solid-phase assay system involving the immobilization of solubilized membrane proteins onto nitrocellulose to monitor binding activity, and several purification steps including affinity chromatography over an AGE bovine serum albumin matrix, two rat liver membrane proteins were isolated that specifically bound AGEs, one migrating at 60 kD (p60) and the other at 90 kD (p90) on SDS-PAGE. NH2-terminal sequence analysis revealed no significant homology between these two proteins nor to any molecules available in sequence databases. Flow cytometric analyses using avian antibodies to purified rat p60 and p90 demonstrated that both proteins are present on rat monocytes and macrophages. Competition studies revealed no crossreactivity between the two antisera; anti-p60 and anti-p90 antisera prevented AGE-protein binding to rat macrophages when added alone or in combination. These results indicate that rat liver contains at least two novel and distinct proteins that recognize AGE-modified macromolecules, although p90 may be related to the previously described 90-kD AGE receptor isolated from RAW 264.7 cells. The constitutive expression of AGE-binding proteins on rat monocytes and macrophages, and the sequestration of circulating AGE-modified proteins by the liver, provides further evidence in support of a role for these molecules in the normal removal of proteins marked as senescent by accumulated glucose-derived covalent addition products, or AGEs.

Synthesis in animal cells of hepatitis B surface antigen particles carrying a receptor for polymerized human serum albumin

Abstract: A recombinant plasmid (pSVS dhfr) encoding the pre-S region and the S gene of human hepatitis B virus (HBV) and murine dihydrofolate reductase (DHFR) cDNA has been used for the transfection of Chinese hamster ovary (CHO) DHFR- cells. Selection of clones resistant to methotrexate has permitted amplification of HBV sequences and an increase in production of hepatitis B surface antigen (HBsAg). HBV-specific transcripts have been characterized. The HBsAg 22-nm particles contain a receptor for polymerized human serum albumin (pHSA) and elicit in animals the synthesis of antireceptor antibodies. This property is ascribed to a 34,000-dalton polypeptide in the particles, which is most likely encoded by the S gene and part of the pre-S region. Especially because the pHSA receptor is most abundantly present on the virion and because, in hepatitis B infection, the appearance of anti-pHSA receptor antibodies seems to be a highly reliable criterion for viral clearance, the HBsAg particles obtained may constitute a particularly efficient vaccine.

Clinical usefulness of estimation of serum fructosamine concentration as a screening test for diabetes mellitus.

Abstract: Fructosamine, a putative measure of serum glycosylated proteins, was measured in 74 subjects referred for oral glucose tolerance tests. A normal range (mean (2 SD] of 1.6 (0.4) mmol/l (40(10) mg/100 ml) derive from results obtained in 83 healthy non-diabetic volunteers permitted the detection of 15 out of 17 (88%) subjects with proved diabetes and yielded only five (9%) false positive diagnoses. Fructosamine concentrations correlated significantly (p less than 0.001) with fasting plasma glucose concentrations (r = 0.76) and glycosylated haemoglobin concentrations (r = 0.70). A longitudinal study suggested that fructosamine concentration was an index of intermediate term (one to three weeks) blood glucose control. Fructosamine concentration was not related to uraemia and did not depend on albumin or total protein concentrations, provided that serum albumin concentrations remained above 30 g/l. Estimation of fructosamine concentrations is a fully automated procedure and may provide a simple means of screening for diabetes mellitus.

Characterizing the Interaction between Tartrazine and Two Serum Albumins by a Hybrid Spectroscopic Approach

Abstract: Tartrazine is an artificial azo dye commonly used in food products. The present study evaluated the interaction of tartrazine with two serum albumins (SAs), human serum albumin (HSA) and bovine serum albumin (BSA), under physiological conditions by means of fluorescence, three-dimensional fluorescence, UV-vis absorption, and circular dichroism (CD) techniques. The fluorescence data showed that tartrazine could bind to the two SAs to form a complex. The binding process was a spontaneous molecular interaction procedure, in which van der Waals and hydrogen bond interactions played a major role. Additionally, as shown by the UV-vis absorption, three-dimensional fluorescence, and CD results, tartrazine could lead to conformational and some microenvironmental changes of both SAs, which may affect the physiological functions of SAs. The work provides important insight into the mechanism of toxicity of tartrazine in vivo.