7-Globulins plasma content

Figure 2. Tracing of ellipsometer recording uneventful sections omitted. To buffer containing oxidized silicon slice on which 7s gamma-globulins had been adsorbed, 0.1 ml of normal activated plasma was added at A, causing adsorption. After 135 min, removal still being minimal, cuvet contents were replaced twice by fresh buffer, and at B, 0.1 ml intact plasma was added, resulting in removal. R ...

The serum cobalophilins, transcobalamin I and III (TCI and TCIII), are immunologically identical and may differ only in their carbohydrate content. TCI moves as an a ] -globulin in standard serum protein electrophoresis, while TCIII moves as an a2-globuIin owing to its lower sialic acid content. Plasma TCIII... 

It must be pointed out that the so-called quasi-albumins described by Poulik and Smithies (P13) are immunologically unrelated to albumin and would be more appropriately named quasi-oi-globulins. These proteins migrate just behind albumin in the vertical starch-gel electrophoretic technique of Smithies (S34) and include the group-specific (Gc) components. A fetal plasma protein of similar electrophoretic mobility is known (B12, B13), whose carbohydrate content is 23 mg/g, which clearly distinguishes it from the glycoprotein fetuin. Occasionally the protein persists and can be observed in some neonatal blood plasmas. 

Nitrogen Content of Human Plasma Albumin and Globulins ... 

If ascites or lymph is to be studied by ImEl, it must be cleared by centrifugation the quantity used for electrophoresis must at least be double that of normal serum. The albumin to globulin ratio is consistently slightly higher than in plasma. In pathological cases it is necessary to determine the protein content (S4, H2). 

Apparently damage of the capillaries in the affected areas is the primary cause of the exudation. If the development of exudate was merely a consequence of lowered colloid osmotic pressure in the plasma, the exudate fluid would be much lower in protein content. In encephalomalacia the albumin globulin ratio of the plasma remains normal after the onset of the disease. 

Prothrombin, the precursor of thrombin, is present in plasma only in small amounts (0.2% of the protein content of plasma) and can be purified by acid precipitation by adsorption on magnesium hydroxide and fractionation with ammonium sulfate. The purified protein contains glucose (6.5%), neuraminic acid (5%), and unidentified amino sugars. A study of the amino acid composition reveals that the molecule contains 19 different amino acids. Prothrombin has only one N-terminal amino acid (alanine), and no carboxy C-terminal can be detected by hydrolyzing the molecule with carboxypeptidase A or B. Prothrombin is an ellipsoid molecule (119 A x 34 A) with a molecular weight of 62,700. On electrophoresis of plasma, prothrombin migrates between the a2- and the jS-globulin. 

A serum aj-globulin which is involved in the transport of vitamin D3 has been separated into two components with different neuraminic acid contents. 2-Opsonic glycoprotein (mol. wt. 2.26 x 10 ), from rat serum, consists of two sub-units joined by disulphide bonds and contains 19 residues of 2-amino-2-deoxy-D-glucose per molecule. Monospecific antiserum to the human opsonic aj-serum-binding glycoprotein and to plasma fibronectin demonstrated antigenic identity of the two macromolecules. ... 

Direct analyses of the content of certain chemical components are often very powerful tools in the discrimination between prot fractions. It was established by the work of Hewitt (98, 99, 100) and McMeekin (137,138) that different albumin fractions from horse serum differ widely in carbohydrate content. Both carbohydrate-containing and carbohydrate-free fractions were prepared by these workers and a crystalline component of each class was obtained by McMeekin (see Part V). All these preparations were very similar as regards molecular sise and shape. In contrast, all fractions of human serum albumin appear to be relatively carbohydrate-free the carbohydrate present in the human plasma proteins is foimd principally in various globulin fractions. 

The content of lipoproteins in many plasma fractions is readily followed by determining the cholesterol content, which may be extremely high (of the order of 20%) in some of the lipoproteins of plasma these include both an a- and a j9-globulin component. Both of these, in addition, contain large amounts of phosphatides and some fatty acid, so that phosphorus and fatty add determinations may also be of great value as anal3Ttical tools in discriminating these from other plasma protein components. 

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