Open AccessThe isoelectric point of serum-globulin as determined by kataphoresis
Author(s) -
F. O. Howitt,
E. B. R. Prideaux
Publication year - 1932
Publication title -
proceedings of the royal society of london. series b, containing papers of a biological character
Language(s) - English
Resource type - Journals
eISSN - 2053-9185
pISSN - 0950-1193
DOI - 10.1098/rspb.1932.0074
Subject(s) - isoelectric point , globulin , isoelectric focusing , chemistry , chromatography , coagulative necrosis , beta globulins , blood proteins , ammonium , ammonium sulfate , homogeneous , gamma globulin , biochemistry , endocrinology , medicine , enzyme , biology , immunology , antibody , organic chemistry , physics , thermodynamics
Following the determination of the isoelectric point of insulin by kataphoretic methods (Howitt and Prideaux, 1932) it appeared to the authors that a similar determination for serum-globulin would be of interest owing to the globulin-like character of insulin. A comparison between the kataphoretic behaviours of these two proteins which are physiologically so different would also be afforded. Previous determinations of the isoelectric point of serum-globulin have generally been based on methods of maximum insolubility, or coagulation. Thus Kugelmass (1922) obtained a value ofp H 4·55, whilst Krebs (1925), employing the coagulative action of proteins on a gold sol, foundp H 5·4. The experiments of Rona and Michaelis (1910, 1927) gave the value 5·44 in close agreement with that of Krebs. Reiner (1927), however, has stated that serumglobulin has a broad isoelectric zone and is not a homogeneous substance. The findings of this worker are probably explained by the conclusions of Svcdberg and Sjögren (1928) that serum-globulin is a chemical entity, which degradated into fractions during normal treatment, such as “salting-out” with ammonium sulphate.