<p>Seminal vesicle protein I (SVP-1) is one of the four major secretory proteins secreted by <taxon tax_id="10141">Cavia porcellus</taxon> (Guinea pig) seminal vesicle epithelium. It is a clotting protein that serves as the substrate in the formation of the copulatory plug. Covalent clotting of this protein is catalyzed by a transglutaminase and involves the formation of gamma-glutamyl-epsilon-lysine crosslinks. SVP-1 sequence contains eight repeats of a twenty four amino acid residue domain. There are seven invariant residues in these repeats, three of them (two lysines and one glutamine) probably participate in the cross-links [<cite idref="PUB00004644"/>].</p> <p>These repeats are also present twice in the N-terminal region of the precursor of human skin elafin, an inhibitor of elastase as well as in the precursor of <taxon tax_id="9823">Sus scrofa</taxon> (Pig) sodium/potassium atpase inhibitor SPAI-2.</p> Seminal vesicle protein I