Albumin function

Su WC, Zhang WG, Zhang S et al (2009) A novel strategy for rapid real-time chiral discrimination of enantiomers using serum albumin functionalized QCM biosensor. Biosens Bioelectron 25 488-492... 

Recent interest focuses on the determination of protein molecular weight by electrophoresis with SDS, on the separation and purification of proteins from living tissue by solubilization with surfactants, and on solution behavior of proteins. " For convenience, most of these studies use anionic surfactants, for which abundant reference data are available, and serum albumins, which bind readily with a variety of species. The serum albumins function as carrier proteins for nutrients, metabolites, and drugs in the bloodstream. Only a few investigations have employed cationic surfactants. ... 

Monkos K. 1996. Viscosity of bovine serum albumin aqueous solutions as a function of temperature and concentration. International Journal of Biological Macromolecules 18, 61-68. 

Accordingly, they generally contain either N- or O-hnked oligosaccharide chains, or both (Chapter 47). Albumin is the major exception it does not contain sugar residues. The ohgosaccharide chains have various functions (Table 47-2). Removal of terminal sialic acid... 

Table 50-2 summarizes the functions of many of the plasma proteins. The remainder of the material in this chapter presents basic information regarding selected plasma proteins albumin, haptoglobin, transferrin, ceruloplasmin, aj-antitrypsin, aj i roglobulin, the immunoglobulins, and the complement system. The lipoproteins are discussed in Chapter 25. 

Mature human albumin consists of one polypeptide chain of 585 amino acids and contains 17 disulfide bonds. By the use of proteases, albumin can be subdivided into three domains, which have different functions. Albumin has an ellipsoidal shape, which means that it does not increase the viscosity of the plasma as much as an elongated molecule such as fibrinogen does. Because of its relatively low molecular mass (about 69 kDa) and high concentration, albumin is thought to be responsible for 75-80% of the osmotic pressure of human plasma. Electrophoretic smdies have shown that the plasma of certain humans lacks albumin. These subjects are said to exhibit analbuminemia. One cause of this condition is a mutation that affects spUcing. Subjects with analbuminemia show only moderate edema, despite the fact that albumin is the major determinant of plasma osmotic pressure. It is thought that the amounts of the other plasma proteins increase and compensate for the lack of albumin. 

Another important function of albumin is its ability to bind various ligands. These include free fatty acids (FFA), calcium, certain steroid hormones, bilirubin, and some of the plasma tryptophan. In addition, albumin appears to play an important role in transport of copper in the human body (see below). A vatiety of drugs, including sulfonamides, penicilhn G, dicumarol, and aspirin, are bound to albumin this finding has important pharmacologic implications. 

Low concentrations of solubilised jS-albumin inhibit ACh release in slices from rat hippocampus and cortex areas which show degeneration in AzD, but not in slices from the striatum which is unaffected. While not totally specific to ACh, since some inhibition of NA and DA and potentiation of glutamate release have been reported, this effect is achieved at concentrations of A/i below those generally neurotoxic. Since jS-amyloid can inhibit choline uptake it is also possible (see Auld, Kar and Quiron 1998) that in order to obtain sufficient choline for ACh synthesis and the continued function of cholinergic neurons, a breakdown of membrane phosphatidyl choline is required leading to cell death (so-called autocannibalism), /i-amyloid can also reduce the secondary effects of Mi receptor activation such as GTPase activity... 

Caeruloplasmin (Cp) is an acute phase glycoprotein with a copper transport function. At least 90% of total plasma copper is bound to Cp with the remaining 10% associated with albumin, histidine and small peptides. Lipid peroxidation requires the presence of trace amounts of transition metals and the copper-containing active site of Cp endows it with antioxidant capacity... 

There is a wide variety of commercially available chiral stationary phases and mobile phase additives.32 34 Preparative scale separations have been performed on the gram scale.32 Many stationary phases are based on chiral polymers such as cellulose or methacrylate, proteins such as human serum albumin or acid glycoprotein, Pirkle-type phases (often based on amino acids), or cyclodextrins. A typical application of a Pirkle phase column was the use of a N-(3,5-dinitrobenzyl)-a-amino phosphonate to synthesize several functionalized chiral stationary phases to separate enantiomers of... 

Specifications for chromatographic packings often describe maximum loading in terms of the maximum capacity of a unit quantity of the packing to bind some analyte, often a well characterized protein such as bovine serum albumin. The static loading capacity35 is very different from functional capacity,2 which is the maximum amount of a particular feedstock that can be loaded and still achieve acceptable purification and recovery. Functional capacity is determined empirically for each type of load and associated set... 

The pathophysiologic mechanisms of portal hypertension and of cirrhosis itself are entwined with the mechanisms of ascites (Fig. 19-3). Cirrhotic changes and the subsequent decrease in synthetic function lead to a decrease in production of albumin (hypoalbuminemia). Albumin is the major intravascular protein involved in maintaining oncotic pressure in the vascular system low serum albumin levels and increased capillary permeability allow fluid to leak from the vascular space into body tissues. This can result in peripheral edema, ascites, and fluid in the pulmonary system. The obstruction of hepatic sinusoids and... 

Approximately 80% of patients with a GFR less than 20 to 30 mL/minute develop metabolic acidosis.38 Metabolic acidosis can increase protein catabolism and decrease albumin synthesis, which promote muscle wasting, and alter bone metabolism. Other consequences associated with metabolic acidosis in CKD include worsening cardiac disease, impaired glucose tolerance, altered growth hormone and thyroid function, and inflammation.38... 

In patients with a history of AED use, a baseline serum concentration may be useful to determine if the drug concentration is below the desired range and if a loading dose is needed. Albumin levels, renal function tests, and liver function tests can also be helpful when assessing antiepileptic therapy. 

The outcome from intraabdominal infection is not determined solely by what transpires in the abdomen. Unsatisfactory outcomes in patients with intraabdominal infections may result from complications that arise in other organ systems. A complication commonly associated with mortality after intraabdominal infection is pneumonia.26 A high APACHE (Acute Physiology And Chronic Health Evaluation) II score, a low serum albumin, and a high New York Heart Association cardiac function status were significantly and independently associated with increased mortality from intraabdominal infection.27... 

Liver function, including AST, ALT, alkaline phosphatase, lactate dehydrogenase (LDH), total and conjugated bilirubin a comprehensive metabolic panel can be ordered (i.e., sodium, potassium, chloride, bicarbonate, blood urea nitrogen, creatinine, glucose, calcium, AST, ALT, alkaline phosphatase, albumin, and total bilirubin), but phosphorus, magnesium, and fractionated... 

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