The citropin peptides from the skin glands of the Australian Blue Mountains tree frog Litoria citropa. Part 2: sequence determination using electrospray mass spectrometry

Abstract

A combination of electrospray mass spectrometry, Lys-C digest/mass spectrometry and automated Edman sequencing provides the amino acid sequences of nineteen citropin peptides isolated from the granular dorsal and submental glands of the Blue Mountains tree frog Litoria citropa. Citropin 1.1 [Gly Leu Phe Asp Val Ile Lys Lys Val Ala Ser Val Ile Gly Gly Leu (NH(2))] and citropin 1.2 [Gly Leu Phe Asp Ile Ile Lys Lys Val Ala Ser Val Val Gly Gly Leu (NH(2))] are the two major skin peptides: both show significant wide-spectrum antibacterial activity.