Peptides from the Skin Glands of the Australian Buzzing Tree Frog Litoria electrica. Comparison with the Skin Peptides of the Red Tree Frog Litoria rubella

Abstract

<jats:p> Eleven peptides have been isolated from the skin glands of the ‘buzzing tree frog’ Litoria electrica. The two most abundant peptides are tryptophyllin L 3.1 [Phe Pro Trp Pro (NH2)] and electrin 1 [Phe Val Pro Ile Tyr Met (NH2)]. These peptides show neither significant antimicrobial nor smooth muscle activity. Tryptophyllin L 3.1 is thought to be a neuromodulator or neurotransmitter, and it is similar in structure to the human endomorphins [e.g. Tyr Pro Trp Phe (NH2)] which act on the γ-receptor. Both Litoria electrica and the ‘red tree frog’ Litoria rubella produce tryptophyllin peptides: it is considered that both species evolved from the same ancestor.