Plasma protein isolates

Differences have also been observed between plasma proteins isolated from different species. Bovine albumin is non-enantioselective for phen-... 

Blood plasma can be refined further to give a variety of functional ingredients. Tybor et al. (1973) described a process for preparing spray-dried plasma protein isolates. Plasma protein isolates in the spray-dried form contain over 90% protein, and as such they are comparable with isolates prepared from soya or other plant materials. 

Utilisation of these ingredients has been investigated in the baking industry. Khan et al. (1979) used bovine plasma protein isolate (96% protein) to replace wheat flour in bread, or as a substitute for egg white... 

Protein-Based Substitutes. Several plant and animal-based proteins have been used in processed meat products to increase yields, reduce reformulation costs, enhance specific functional properties, and decrease fat content. Examples of these protein additives are wheat flour, wheat gluten, soy flour, soy protein concentrate, soy protein isolate, textured soy protein, cottonseed flour, oat flour, com germ meal, nonfat dry milk, caseinates, whey proteins, surimi, blood plasma, and egg proteins. Most of these protein ingredients can be included in cooked sausages with a maximum level allowed up to 3.5% of the formulation, except soy protein isolate and caseinates are restricted to 2% (44). 

KELL blood group antigen is a plasma membrane protein isolated from red cells homologous to zinc-binding glycoproteins with neutral endopeptidase activity. 

The preparation of antibodies specific for the individual plasma proteins has greatly facilitated their smdy, allowing the precipitation and isolation of pure proteins from the complex mixmre present in tissues or plasma. In addition, the use of isotopes has made possible the determination of their pathways of biosynthesis and of their turnover rates in plasma. 

This has been estabhshed by experiments at the whole-animal level (eg, hepatectomy) and by use of the isolated perfused Hver preparation, of hver slices, of liver homogenates, and of in vitro translation systems using preparations of mRNA extracted from liver. However, the y-globulins are synthesized in plasma cells and certain plasma proteins are synthesized in other sites, such as endothelial cells. 

The half-life of a plasma protein can be detetmined by labeling the isolated pute protein with under mild,... 

Modified procedure (ASC kit) Ascorbic acid is isolated from plasma proteins and uric acid in a single-step liquid gel chromatography procedure and its amount... 

The sample materials from which proteins for proteomics studies may be extracted include fresh or snap-frozen cells from varied sources such as biological fluids, (serum, urine, plasma) and solid tissues such as biopsy specimens. Moreover, proteins isolated from ethanol-fixed paraffin-embedded tissues can be utilized for MS analysis.2 Protocols for the identification of proteins from formalin-fixed paraffin-embedded (FFPE) tissues have been recently developed.3 4 FFPE materials are the most common forms of biopsy archives utilized worldwide, and represent an important advancement for the large-scale interrogation of proteins in archival patient-derived materials. Finally, laser capture microdissected tissues have been successfully used for MS analysis.45... 

Ticlopidine is metabolized extensively by the liver only trace amounts of intact drug are detected in the urine. Following an oral dose, 60% is recovered in the urine and 23% in the feces. Approximately, 33% of the dose excreted in the feces is intact ticlopidine, possibly excreted in the bile. Approximately 40% to 50% of the metabolites circulating in plasma are covalently bound to plasma proteins, probably by acylation. Although analysis of urine and plasma indicates 20 metabolites or more, no metabolite that accounts for the activity of ticlopidine has been isolated. 

J Oravcova, D Sojkova, W Lindner. Comparison of the Humel—Dreyer method in high-performance liquid chromatography and capillary electrophoresis conditions for study of the interactions of (RS)- (R)- and (S)-carvedilol with isolated plasma proteins. J Chromatogr B 682 349-357, 1996. 

At one stage in the development of modern kinetic understanding it was believed that displacement of one drug from its binding site on plasma proteins by another with greater affinity was a common interaction which explained many clinical events. Much of this belief came from experiments in the laboratory where it was easy to demonstrate such displacement. Unfortunately, isolated solutions of plasma proteins do not tell the full story, for, in the body, a rising free fraction of a drug is usually matched by enhanced clearance and the re-establishment of a new steady state. 

Miller, L. L., John, D. W. Nutritional, hormonal, and temporal factors regulating net plasma protein biosynthesis in the isolated perfused rat liver. In Plasma protein metabolism, pp. 207. Rothschild, M. A., Waldmann, T. (eds.). New York, London Academic Press 1970... 

Bovine Serum Albumin. Since Polis et al. (1950) crystallized bovine serum albumin from whey and demonstrated that it was identical in all properties investigated to blood serum albumin, except in its electrophoretic behavior at pH 4.0, very little work has been done on this protein as isolated from milk. However, much work has been done on the protein isolated from bovine blood plasma. There is considerable evidence that serum albumin is heterogeneous. For example, Spencer and King (1971) have demonstrated several protein bands by electrophoretic focusing, with two major isoelectric components differing by one unit of charge. The chemical nature of this difference is not known. 

Soy protein preparations contain a variety of biologically active compounds including saponins, fibers, trypsin inhibitors, and isoflavones (Potter, 2000). Hamsters and rats fed ethanol-extracted soy protein isolates had no ability to lower plasma cholesterol compared to intact soy protein isolates (Lucas et al., 2001 Ni et al., 1999). Extraction with ethanol is a treatment that would remove saponins, isoflavones, and other phytochemicals from the protein. Although one study showed that ethanol washing did not... 

Sommerfelt, C., Paper electrophoresis of isolated plasma protein fractions. Scand. J. Clin, it Lab. Invest. 5, 299 (1953). 

Lijnen HR, Hoylaerts M, Collen D. Isolation and characterization of human plasma protein with high affinity for lysine binding sites in plasminogen. J Biol Chem 1980 225 10,214-10,222. 

K. P. Simneigren and M. J. Rovctto. Tine effects of hynluronJdasc on intenridal hydration, plasma protein exclusion and mferovnacular permeability in tbc isolated perilled rat heart. Micro vote. Res. 3ft 296 (1985). 

M44. Morton, R. E., and Zilversmit, D. B., Inter-relationship of lipids transferred by the lipid transfer protein isolated from human lipoprotein-deficient plasma. /. Biol. Chem. 258, 11751-11757 (1983). 

Diabetic patients are 3 4 times more susceptible to atherosclerosis and vascular insufficiency. The situation is similar for those suffering from renal insufficiency, independent of diabetes. Makita et al.5sl found that there was a direct correlation CP < 0.005) between serum AGE-peptide levels and renal function, as assessed by creatinine clearance. This led Bucala et a/.145 to consider that the modification of the plasma proteins, such as LDL, may arise due to the reaction with reactive, circulating AGE-peptides rather than glucose. AGE-LDL did form readily in vitro when native LDL was incubated with either synthesised AGE-peptides or AGE-peptides isolated directly from the plasma of patients. Such AGE-LDL exhibited markedly impaired clearance kinetics when injected into transgenic mice, expressing human LDL receptor. Their data indicate that AGE modification could contribute to elevated LDL levels in patients with diabetes or renal insufficiency. This hypothesis was further supported by the administration of AG to diabetic patients, when circulating levels of LDL decreased by almost 30%. Levels of Hb-AGE decreased too. 

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