112 



The Biochemistry of Semen 



membranes which are impermeable to blood serum proteins 

 (Huggins, Scott and Heinen, 1942). The electrophoretic pattern of 

 the non-dialysable portion from five different specimens of human 

 seminal plasma has been examined by Gray and Huggins (1942) who 

 observed four distinct components which corresponded to serum 

 albumin (17-7-22-7%), a-globulin (19-8-27-8%), i5-globulin (34-3- 

 44-5%), and y-globulin (11 -4-21 0%). Ross, Moore and Miller 



20 40 60 

 Minutes after ejaculation 



Fig. 1 1 . Increase of non-protein nitrogen and amino-nitrogen content in 



human semen on incubation at 37°. 



(Jacobsson, 1950) 



(1942) also carried out an electrophoretic and chemical analysis 

 of human seminal plasma in which they distinguished five protein 

 fractions: albumin (less than 002%); 'nucleoprotein' (less than 

 004%); proteose ('Pi'), which was not heat-coagulable and passed 

 through a membrane of 25 A pore diameter; two water-insoluble 

 proteins ('Pg' and 'P3') and a mucoprotein ('P4') which contained 

 9-3% N, 10-8% hexosamine, and gave on hydrolysis with n-HCI 

 reducing substances (26-8%) but no uronic acid. The strongly 

 positive periodic acid-Schifif reaction which is very characteristic 



