No abstract

The protein SV-IV, a major protein secreted from the rat seminal vesicle epithelium, is a basic protein with immunomodulatory, anti-inflammatory, and procoagulant activity. Predictions suggested that this protein is very flexible, with its three tyrosyl residues presumably located in water-exposed segments of the primary structure. The solution behaviour of the protein was investigated by two types of spectroscopic techniques. Modifications of the spectral characteristics of tyrosyl residues induced by changes of protein concentration were demonstrated by absorption and fluorescence experiments. In addition, secondary structure rearrangements associated with a possible self-association equilibrium were highlighted by far-UV CD spectra. The equilibrium, confirmed by chromatographic techniques, appears to control some biological properties of the protein.

No abstract

The pretreatment of epididymal spermatozoa with SV-IV, one of the major secretory protein produced by the epithelium of adult rat seminal vesicles, was found to markedly decrease their ability to induce in vivo peritoneal macrophage activation, measured as class II major histocompatibility complex surface antigen expression, superoxide anion production, phagocytic activity, and antigen presentation. In addition, the treatment of spermatozoa with SV-IV produced a significant decrease of their immunogenicity evaluated in vitro by [3H]thymidine incorporation in splenocyte/spermatozoon co-culture. The concurrent presence of SV-IV and transglutaminase, an enzyme secreted in large amounts from the rat anterior prostate, amplified these phenomena. The suppression of the epididymal sperm immunogenicity is suggested to be of crucial importance for the prevention of the immune response to the sperm introduced in the immunocompetent female genital tract during coitus.

No abstract