Globulin

name for a family of proteins precipitated from plasma or serum by half-saturation with ammonium sulfate (i.e., addition of an equal volume of saturated ammonium sulfate)

Description
Globulins can further be fractionated by solubility, electrophoresis, ultracentrifugation, and other separation methods into many subgroups, the main groups being &#945;-,&#946;-,and &#947;-globulins;these differ with respect to associated lipids or carbohydrates. They contain several physiologically important factors, such as immunoglobulins (antibodies) found in the &#946; and &#947; fractions, lipoproteins in the &#945; and &#946; fractions, gluco- or muco-proteins (orosomucoid, haptoglobin) and metal-binding and metal-transporting proteins (transferrin, siderophillin, ceruloplasmin). Other substances found in globulin fractions are: macroglobulin, plasminogen, prothrombin, euglobulin, antihemophilic globulin, fibrinogen, cryoglobulin