[Characterization of SH groups in the membrane proteins of human spermatozoa]

Membrane proteins rich in SH- groups were identified in human ejaculated spermatozoon, using the alkylation reaction with radioactive iodoacetic acid with a subsequent determination of the electrophoretic characterization of the proteins, as well as their comparison with the proteins in seminal plasma and blood serum of the same individuals. The determination of the incorporated radioactivity shows that out of 20 proteic bands identified by staining with Coomassie Blue, only 9 were alkylated with the iodoacetate. Among these 9 proteic bands, 4 are glycoproteins since they give a PAS positive reaction. All the proteins which incorporated the marked iodoacetate had a molecular weight below 67,000 daltons with a predominance of molecular weight below 25,000 daltons. A comparison of the electrophoresis obtained from the spermatozoon's plasmatic membrane, seminal plasma and blood serum, one finds that among the 9 proteins which were alkylated with the iodoacetate in the plasmatic membranes, two, bands I and IV are also found in the seminal plasma and blood serum, two more, bands VII and IX are found in the membranes and seminal plasma, but not in blood serum, while the rest are only found in the spermatozoon.