Albumin sedimentation constant

The molecular-sieving effect on proteins has been very clearly demonstrated by Pedersen (1962). Bovine serum albumin, obtained by fractionated ammonium sulfate precipitation, was filtered through a column of cross-linked dextran of water regain 15 gm/gm (Sephadex G-200). Monomer and dimer forms were easily separated from each other and from other components of larger sedimentation constants (Fig. 8). Heterogeneity in the monomer as well as in the dimer preparation was indicated... 

Normal individuals excrete 31 mg of albumin in their urine daily. The studies of the physical and chemical properties of the urinary albumin have established that the urinary protein is identical to the blood protein. Both serum and urinary albumin have the same mobilities on free-starch electrophoresis and im-muno-electrophoresis. The sedimentation constants and the diffusion rates of the two proteins are similar, and their molecular weight must be of the order of 73,000. The two proteins react identically antigeni-cally. 

Quite apart from the X-component, certain purified plasma globulin fractions—notably some a- and j3-globulins—have sedimentation constants (s,o) near 4.5 S, and are indistinguishable in this respect from albumin. ... 

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