A heritable variant of mouse liver ornithine aminotransferase (EC 2.6.1.13) induced by ethylnitrosourea

A variant of ornithine aminotransferase (OAT, EC 2.6.1.13) has been detected in an offspring of a male mouse treated with ethylnitrosourea. The evidence presented to support the identification of the protein variant (ENU 2) as altered OAT includes (a) a corresponding 50% decrease in the abundance of a protein, located one charge unit basic to the variant, which comigrates on two-dimensional gel patterns with purified mouse liver OAT; (b) the binding of anti-rat-OAT antibody to the variant; (c) the increased abundance of the variant protein in the livers of mice fed a high protein diet (85% casein); and (d) purification of the variant through an OAT purification protocol.