at the greater than millimolar concentrations at which cross-spermidine and spermine are present in normal rat seminal plasma , these polyamines attenuate the formation of hard clots in reconstituted rat semen coagulation systems , seemingly by competing with lysyl residues in vesicular secretion proteins as transglutaminase amine donor substrates , and thus preventing formation of epsilon- ( gamma-glutamyl ) lysine cross-bridges .
C0032433
polyamines
C0002508
amine