Seminal vesicle-secreted proteins and their reactions during gelation and liquefaction of human semen.

TLDR

Fibronectin is incorporated into the seminal gel and linked to semenogelin, while lactoferrin remains in solution; both gel‑bound proteins are progressively fragmented and solubilized by prostate‑specific antigen during liquefaction. Measurements show that both fibronectin and lactoferrin in seminal fluid originate from the seminal vesicles and ampullae, and lactoferrin is not degraded by seminal proteases.

Abstract

The comparison of measurements of fibronectin and lactoferrin in ejaculates from vasectomized men, subjects with functional deficiency or aplasia of the seminal vesicles, and reference subjects provided evidence that both the fibronectin and the lactoferrin in human seminal fluid originate from the seminal vesicles and the ampullae. The fibronectin is incorporated in the framework of the seminal gel formed during the immediate postejaculatory phase, whereas the lactoferrin remains in solution. In the seminal gel fibronectin is linked to its predominant structural protein, a high molecular weight seminal vesicle protein (semenogelin). Both the gel-bound fibronectin and semenogelin are progressively fragmented and solubilized by the abundant prostatic kallikrein-like protease (prostate-specific antigen) during and after seminal gel liquefaction. Lactoferrin remains essentially unaffected by the seminal proteases.