Biological activity of obiopeptide-1, a synthetic peptide derived from the native immune-regulator obioactin.

Tachyzoites of Toxoplasma gondii were killed in mouse macrophage and human somatic cell monolayers by a novel synthetic peptide (Obiopeptide-1) which is a Glycil-penta-Glutaminate (GpG) derivative of native Obioactin. In view of the worldwide prevalence of this protozoan disease and the lack of effective treatments, Obiopeptide-1 may be a new and unique antimicrobial active substance of non-antibiotic chemotherapeutic agents for intracellular parasites, T. gondii and associated nonspecific hypoimmune responses that occur in infected hosts.