Depeiges A, Force A, Dufaure J P
Comp Biochem Physiol B. 1987;86(2):233-40. doi: 10.1016/0305-0491(87)90283-5.
From epididymal fluid samples taken at three different times during the reproductive period (early April, late April, mid-May), the soluble proteins were separated with one dimensional electrophoresis on polyacrylamide gel. Their evolution was studied: firstly quantitatively, after staining with Coomassie blue, or, for one protein (the "L" protein), by immunodetection; secondly, according to their glycosylation after transfer to nitrocellulose and treatment with a set of labelled lectins: from Wheat germ, Ricinus communis, Lens culinaris, Asparagus pea or Canavalia ensiformis, with or without use of their specific inhibitor sugars. At least 15 proteins underwent a quantitative and/or qualitative evolution, mainly during the month of April. Protein "L" (19 kDa), which is androgen dependent and which fixates on to spermatozoa during their epididymal transit, appears to be little or not glycosylated. By contrast its accumulation in the epididymal canal increases considerably during the month of April. Five other proteins proved to be especially interesting because of their evolution during this same period, notably the MW 94, 67, 35, 29 and 25.5 kDa proteins. With the exception of the 67 kDa all the others increased quantitatively. All were decisively enriched in mannose or in methyl-mannoside residues. The proteins of MW 29 and 25.5 kDa were also enriched in galactose or N-acetyl galactosamine residues. These findings are of physiological significance since they are set up concomitantly with the acquisition of maximum motility of spermatozoa in the distal segment of the epididymis, and they coincide with a very great increase in testosteronemia.