Abstract
Hen egg white ovomacroglobulin purified by Miller and Feeney without reference to its activity was shown to have a protease inhibitory activity towards trypsin, papain, and thermolysin. It has four subunits of equal molecular weight (175, 000 by SDSPAGE) and each two of which are disulfide bonded. Upon incubation with trypsin it yields a fragment of Mr=80, 000 plus smaller ones. The subunit composition, amino acid composition and a newly found protease inhibitory activity place ovomacroglobulin as a closely related protein to human serum α2-macroglobulin.
