Title: Nakada T, et al. Evidence for processing enzymes in the abdominal gland of the newt, Cynops pyrrhogaster, that generate sodefrin from its biosynthetic precursor. Zoolog Sci. 2007 May;24(5):521-4.
Title: Yumiko Obayashi, et al. Proteolytic enzymes in coastal surface seawater: Significant activity of endopeptidases and exopeptidases Limnol. Oceanogr., 50(2), 2005, 722-726.
