Tachyplesin is an antimicrobial peptide isolated from the horseshoe crab with a molecular weight of 2.36 kDa and the amino acid sequence KWCFRVCYRGICYRRCR.[1]
Murakami T, Niwa M, Tokunaga F, Miyata T, Iwanaga S (1991). "Direct virus inactivation of tachyplesin I and its isopeptides from horseshoe crab hemocytes". Chemotherapy. 37 (5): 327–34. doi:10.1159/000238875. PMID1666545.