γ-Glutamyltransferase bound to prostatic subcellular organelles and in free form in human seminal plasma

Most of the γglutamyltransferase occurring in semen was found to be bound to the membranes of prostatic organelles, as is the case with Mg+plus;-Ca+plus;-dependent ATPase, and Zn+plus;-dependent peptidase hydrolysing succinyl (alanine)3-paranitroanilide. Organelie-bound γglutamyltransferase was released in a water-soluble form by papain. Charge shift electrophoresis revealed the presence in seminal fluid of a small additional amount of γglutamyltransferase that is unbound and water-soluble, but also of prostatic origin. After papain treatment there was no sign of the organelle-bound Zn+plus;-dependent peptidase activity, nor of the Mg+plus;-Ca+plus; dependent ATPase activity, both having been inactivated by the papain. Both organelle-bound γglutamyltransferase and Zn+plus;-dependent peptidase could be rendered soluble in active form with the non-ionic detergent Triton X-100