- Source: Aciculitin
Aciculitins are antifungal cyclic peptides isolated from a marine sponge. There are 3 Aciculitins that are isolated from the Lithistid sponge Aciculites orientalis that differ by their homologous lipid residues.
Aciculitin D is a similar cyclic peptide to Aciculitin A-C. It was isolated from Poecillastra sp. marine sponge that is collected from the deep sea. Based on its molecular formula, Aciculitin D is the most similar to Aciculitin B structure wise since they only differ in one amino acid substitution. The structure of Aciculitin B contains one extra glutamine while the structure of Aciculitin D has one extra L-Threonine. Although the two cyclic peptides contain slightly different amino acids, they still have the same overall charge because both glutamine and L-Threonine are considered neutral amino acids.
Cytotoxicity
Aciculitin A-C exhibits cytotoxicity against human colon tumor cell line HCT-116 with IC50 value of 0.5 μg/mL.
Aciculitin D exhibits cytotoxicity against human colon tumor cell line HCT-116 with IC50 value of 0.51 μM. Aciculitin D also exhibits cytotoxicity against HeLa, human cervical cells with IC50 value of 0.57 μM.
Further reading
Otero-Gonzáiez, Anselmo Jesus; Magalhães, Beatriz Simas; Garcia-Villarino, Monica; López-Abarrategui, Carlos; Sousa, Daniel Amaro; Dias, Simoni Campos; Franco, Octávio Luiz (May 2010). "Antimicrobial peptides from marine invertebrates as a new frontier for microbial infection control". The FASEB Journal. 24 (5): 1320–1334. doi:10.1096/fj.09-143388. PMID 20065108. S2CID 23976702.