Molecular forms of alkaline phosphatase of ram seminal plasma — Some properties and changes in pathological process of reproductive organs

Abstract

Three molecular forms of alkaline phosphatase were isolated from ram seminal plasma. These forms, activated with Mg 2+ ions, were characterized by very similar pH optima, K m constant, and molecular weight. They differed in electrophoretic mobility, the latter being most probably determined by the different position of N-acetylneuraminyl groups in protein structures. Sialic acid also played a protective function for the catalytic centre. Isolated molecular forms possessed antigenic properties. Immunological serum for phosphatase proteins either inhibited or stabilized activity of alkaline phosphatase, depending on the value of the protein ratio. During experimentally induced inflammation of ram reproductive organs, a gradual decrease of the activity of alkaline phosphatase was noted, together with changes in its electrophoretic profile. This phenomenon is most likely caused by intensive synthesis of sialic acid in pathologically changed reproductive organs of the ram.