CHAPTER IV 



Intracellular Enzymes, Metalloproteins, 



Nucleoproteins, and other Protein Constituents 



of Spermatozoa 



Mechanical separation of sperm from seminal plasma; release of intra- 

 cellular proteins from damaged spermatozoa. Removal of the sperm 

 nucleus from the cytoplasm. Protein-bound iron, zinc, and copper. Cyto- 

 chrome. Catalase. Hyaluronidase and other 'lytic' agents. Sperm nucleo- 

 proteins. Deoxyribonucleic acid. The basic nuclear proteins; protamines 

 and histones. The non-basic nuclear proteins; karyogen and chromosomin. 

 Keratin-like protein of the sperm membrane. 



Mechanical separation of sperm from seminal plasma; release of intra- 

 cellular proteins from damaged spermatozoa 

 A STUDY of the proteins present in the spermatozoa themselves calls 

 for an efficient separation of the sperm from the seminal plasma, by 

 centrifugation and washing. However, the spermatozoa are filiform 

 structures, highly vulnerable to mechanical damage. Centrifugation, 

 dilution and washing may inflict an injury upon the sperm cell which, 

 even if not apparent upon ordinary microscopic examination, never- 

 theless results in a leakage of certain proteins from the spermatozoa 

 into the surrounding medium. Thus, for instance, cytochrome c is 

 easily detached from the sperm structure as a result of cellular 

 damage or prolonged storage of spermatozoa (Mann, 1951a); be- 

 cause of that, the spectroscopic detection of extracellular cyto- 

 chrome c provides a sensitive indicator of 'senescence' changes in 

 spermatozoa. Another example is the release of hyaluronidase by 

 the spermatozoa (see p. 94). At one time, this phenomenon was 

 ascribed to a true secretory function of the normal sperm cells 

 but more recent evidence suggests that the liberation of hyaluroni- 

 dase takes place in an ageing or moribund cell population. Yet 

 another phenomenon in this category is the loss of lipoprotein 

 from the 'lipid capsule' of the sperm cell which may easily occur as 

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