Globulins, serum electrophoresis

Albumin is synthesized in the liver cell. The rate of synthesis is 12—17 g/day (150-250 mg/kg BW), which can be enhanced 3—4 times due to a loss of albumin. The albumin pool of the organism is approx. 500 g. Half-life is 18—21 days. Albumin is determined as a part of serum electrophoresis either quantitatively (g/l or g/dl, respectively) or as a relative percentage (rel. %). Concentrations of globulins are also quantified in this way. 

AAT is the major constituent of the tti-glohulin band on routine clinical serum electrophoresis. The two other relatively high concentration tt]-globulins, AAG and a-lipoprotein, do not stain well with peptide stains because of their high contents of CHO and lipid, respectively. Some genetic variants of AAT may be detectable by visual examination of the electrophoresis pattern because of altered mobility or decreased concentration. 

AMG and Hp together constitute most of the aa-globulin zone on routine clinical serum electrophoresis. In the newborn period, and in in vivo hemolysis, AMG alone is the major contributor to this zone. 

Figure 2 Serum electrophoresis of a patient with a small monoclonal band (top) CE (bottom) agarose electrophoresis l = internal standard A = albumin ai =ai-globulin a2 = a2-glob-ulin, T = transferrin C = complement M = monoclonal band > = >-globulins X = marker). CE conditions capillary 30cmx 50 pm (ID), 9kV, detection at214nm. Separation buffer 7g boric acid, 7g sodium carbonate, and 5 g of polyethylene glycol 8000 in 1000 ml water.

Serum protein electrophoresis — increased or2 globulin serum aspartate aminotransferase 90 IU/1. The fasting plasma was turbid, triglycerides 3.8 mmol/1, lipoprotein electrophoresis — increased pre- band ECG. — sinus tachycardia 120/min and peaked P waves. The clinical diagnosis of Refsum s disease was confirmed by the finding of large amounts of phytanic acid in the patient s plasma (vide infra). 

Torres, A. R., Krueger, G. G., and Peterson, E. A., Purification of Gc-2 globulin from human serum by displacement chromatography a model for the isolation of marker proteins identified by two dimensional electrophoresis, Anal. Biochem., 144, 469, 1985. 

The third test of protein homogeneity, developments from which remain in common use, was that of electrophoresis. Arne Tiselius had been a research assistant in Svedberg s laboratory. From 1925 he pioneered the application of electrophoresis to the analysis and separation of protein mixtures, showing with dialyzed serum differences in mobility of the protein components and the presence of three classes of globulins, a, B, and y. 

On examination of the urine and serum of numerous patients with suspected paraproteinemia in both Jamaicans and Africans between 1962 and 1966, it was concluded that whenever a low total serum y-globulin level with a normal serum electrophoretic pattern were encountered in a suspected case of multiple myelomatosis, it was then essential to obtain also a specimen of urine from such a patient for further electrophoretic examination. Invariably simultaneous electrophoresis of such sera and urines proved to be diagnostic, even when the classical heat test for Bence Jones protein was negative. Consequently it was found that concurrent electrophoresis of scrum and urine was the first means of detecting multiple myelomatosis in no less than 20% of the patients, which were subsequently confirmed either by bone marrow biopsy or X-ray examination or both (M3). 

Classical electrophoresis of CSF has largely been abandoned. In physiological conditions, in comparison with serum, the expression of prealbumin, /3-globulin,... 

Zone electrophoresis is mostly used for biological applications. Peptide separation and the measurement of protein fractions from blood serum (proteinogram of albumin and o-, (3- and 7-globulins) are among the better known applications. This TLC for biochemists is useful for the separation of polysaccharides, nucleic acids (for DNA sequencing), proteins and other colloidal species. 

FIGURE 16.20 (a) A normal electrophoresis pattern of blood serum, (b) An abnormal pattern, with elevated y-globulin, indicating the possibility of liver disease, collagen disorder, or infection. 

Al. Abdel-Wahab, E. M., Rees, V. H., and Laurence, D. J. R., Evaluation of the albumin-globulin ratio of blood plasma or serum by paper electrophoresis. In Paper Electrophoresis, Ciba Foundation Symposium (G. E. W. Wolstenholme and E. C. P. Millar, eds.), pp. 30-39. Churchill, London, 1958. 

Fig. 62a, b, and c. Some staining techniques adapted to paper electrophoresis. Sample human serum. Run continuous electrophoresis. The fractions are labeled according to the proposed reference system (see text). The known fractions are +86.20 Albumin +86.18 oij-globulin +86.12 a2-globulin +86.07 3-globulin —86.02 Y-globulin. 

Figure 1 shows diagrammatically the arrangement of the proteins of the serum in accordance with their mobilities, as would be found in a classical electrophoretical pattern obtained by electrophoresis of normal serum at pH 8.6 in veronal buffer. The Bence-Jones and myeloma globulins are also placed in areas where they were found in respect to the serum proteins indicated (see Table V for other data on these proteins). In each system, in both the hepatic and extrahepatic proteins (26), the ala-thr ratios change in the same direction as the... 

The latter group (M13, M14) separated two types of KIK factor from cancerous gastric juice. The first was a mucopolysaccharide and the second a mucoprotein. Others thought it to be a mucopolypeptide. A similar factor from cancerous ascitic fluid (19) contained 50-60% hexoses, 1.5% tyrosine, and 10% protein by biuret reaction. It formed a single peak at pH range 1.5-10.0 on paper electrophoresis, and at pH 8.6 moved with the mobility of serum y-globulin. 

---