Isolation and properties of immune lactoglobulins from bovine whey.

It has already been reported that the principal protein of bovine colostrum is immune lactoglobulin, and a procedure has been described for the isolation of this protein (1). While the immune properties of colostrum have been generally recognized, it is widely believed that this is a specific quality of colostrum, and that immune properties are absent from the later milk or are present only in traces. In this communication, it will be demonstrated that the immune proteins are present in normal milk as shown by an electrophoretic analysis of the whey and by the isolation of these proteins in electrophoretically homogeneous state. The immune activity of milk like that of colostrum is associated with two different immune lactoglobulins which differ in electrophoretic mobility, solubility, and analytical composition (l-3). For convenience, they may be described as euglobulin and pseudoglobulin. Some of the properties of these proteins will be discussed.