Ethanol Fractionation of Plasma and Electrophoretic Identification of Insulin-Binding Antibody

Apparent Inhibition of Liver Insulinase Activity by Serum and Serum Fractions Containing Insulin-Binding Antibody

“…The possibility of identity among some of the diverse anti-insulin activities reported by different investigators has been considered elsewhere (9). The present study indicates that at least two manifestations of "anti-insulin" activity are referable to the same phenomenon, namely binding of insulin by antibody.…”

“…I... per mg. insulin and protected from extensive irradiation damage (11) according to methods previously described (9). At the higher specific activities, it was not possible to prevent such damage completely and 3 to 5 per cent was frequently found to be altered.…”

“…In two subjects there were observed a small amount of insulin binding in fraction IV -VI (mainly albumin with a small amount of ,8 and a globulins) as well as more marked binding in the other two fractions. In all cases, bound insulin migrated in the inter -y -8 region on electrophoresis, regardless of the fraction in which the antibody was recovered (9).…”

“…A study of the distribution of insulin-binding antibody among serum fractions separated with cold ethanol revealed that antibody was restricted to fraction I + III (which is comprised chiefly of /8 and a globulins) in most subjects (9). In some, antibody was recovered in fraction II (primarily y globulins with a small amount of /l2 globulin) as well as in fraction I + III.…”

Species-Specificity of Human Anti-Beef, Pork Insulin Serum

“…The conditions employed for these runs as well as the assay of radioactivity on the strips by means of an automatic strip counter have been described in detail previously (1). Chromatographic or electrophoretic separation of free insulin and insulin bound to antibody depends on the adsorption of free insulin to the paper at the site of application (1,8) while antibody-bound insulin migrates with the inter-y-ft-globulins (9). The amounts of free insulin and bound insulin in each mixture were determined from the areas under the respective peaks of radioactivity in the two positions.…”