Semenogelin is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

that is involved in the formation of a gel matrix that encases ejaculated spermatozoa, preventing

capacitation Capacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte. This step is a biochemical event; the sperm move normally and look mature prior to capacitation. ''In ...

. It blocks capacitation mainly via inhibition of

reactive oxygen species In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () p ...

(ROS) generation. Proteolysis by prostate-specific antigen (PSA) breaks down the gel matrix and allows the spermatozoa to move more freely. The cleavage products of the semenogelins constitute the main antibacterial components in human seminal plasma. There are two variants of the semenogelin protein: semenogelin 1 and semenogelin 2. Semenogelin along with prostate-specific antigen, are commonly tested for during crime scene investigation.

References

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