The Structures of Four Tryptophyllin and Three Rubellidin Peptides From the Australian Red Tree Frog Litoria rubella

Abstract

The peptide content of the glandular secretions of Litoria rubella specimens collected from Derby and Lake Argyle (Kimberley region of Western Australia) and from near Darwin in the Northern Territory are all quite different; this suggests that there are different frog populations in these three areas. These different populations may be indicative of either different species or different sub-species of frog. There are two separate families of peptides in the glandular secretion of 'Litoria rubella': ( i ) those corresponding to the tryptophyllin family (tetra- to hepta -peptides all containing the residues Pro and Trp ), and (ii) the rubellidinins ( pentapeptides all containing two Phe residues at positions 3 and 4). To ate, no biological activity has been found for any of these peptides, but it is suspected that the tryptophyllins may be neurotransmitters or neuromodulators.

An unusual kynurenine‐containing opioid tetrapeptide from the skin gland secretion of the Australian red tree frog Litoria rubella. Sequence determination by electrospray mass spectrometry

“…However, the full sequence of peptide D [Fig. and Table (MH + = 565)] was not identified in the original studies, and was not discussed in the resultant articles …”

“…HPLC skin peptide profile (January 1993) of L. rubella collected from the Simpson ranges near Alice Springs. For Experimental details, see Steinborner et al …”

Skin peptides from anurans of the Litoria rubella Group: sequence determination using electrospray mass spectrometry. Opioid activity of two major peptides

“…Two members of the Litoria rubella Group that we have studied previously, Litoria rubella 5, 6 and L.electrica ,7 do not produce peptides like those outlined above, but exude small peptides of a type first identified from Phyllomedusa rohdei and called tryptophyllins 8. Tryptophyllins L (L for Litoria ) and other peptides isolated from L. rubella and L. electrica were identified by mass spectrometric techniques5–7 and are listed in Table 1.…”

Host‐defence peptide profiles of the skin secretions of interspecific hybrid tree frogs and their parents, female Litoria splendida and male Litoria caerulea

“…Amphibian skin-peptide profiles are not only typically characteristic of individual species, but can also distinguish subspecies or particular populations within a species [4][5][6][7][8], despite seasonal variation in the skinpeptide content of some amphibians [4,5].…”

“…Many of these defence compounds are peptides. Some of the peptides are vasodilators, whereas others show antimicrobial activity or inhibit the formation of nitric oxide by neuronal nitric oxide synthase (nNOS) [1][2][3][4][5].Amphibian skin-peptide profiles are not only typically characteristic of individual species, but can also distinguish subspecies or particular populations within a species [4][5][6][7][8], despite seasonal variation in the skinpeptide content of some amphibians [4,5].Many species of amphibians hybridize naturally with some forming extensive zones of hybridization [9][10][11][12][13][14][15][16][17][18][19][20]. Five healthy adult female first-generation hybrid tree frogs were produced by interspecific breeding of closely related tree frogs Litoria splendida and L. caerulea in a cage containing large numbers of males and females of both species.…”