Pier Carlo Montecucchi

Phyllomedusa skin: A huge factory and store-house of a variety of active peptides

The skin of the neotropical hylid frogs belonging to the subfamily. Phyllomedusinae is a formidable factory and store-house of a variety of active peptides belonging to seven distinct families: the caeruleins (represented by phyllocaerulein), the bradykinins (phyllokinin), the tachykinins (phyllomedusin), the bombesins (phyllolitorin, [Leu8]phyllolitorin, rohdei-litorin), sauvagine, the dermorphins (dermorphin, [Hyp6]dermorphin) and finally the tryptophyllins (a set of 8-11 members). Another linear peptide and three diketopiperazines should be added to the list. The biochemical and pharmacological positions of the Phyllomedusa peptides within their families is briefly discussed, dwelling upon some recent and controversial data.

Amino acid composition and sequence of kassinin, a tachykinin dodecapeptide from the skin of the African frog Kassina senegalensis

Methanol extracts of the skin of the African amphibian Kassina senegalensis contain a dodecapeptide, kassinin, belonging to the family of tachykinins or physalaemin-like peptides. Kassinin, like all other natural tachykinins, possesses the characteristic C-terminal tripeptide Gly-Leu-Met-NH2 and a phenylalanine residue in position 5 from the C-terminus. However, the amino acid sequence in the N-moiety of the molecule differs sharply from that of the other tachykinins.

Reversed-phase high-performance liquid chromatographic characterization of a novel proline-rich trytophyllin

Abstract A tryptophan-containing tridecapeptide of amphibian origin (tryptophyllin-13, TPH-13), having the sequence

Occurrence of Asn2, Leu5-caerulein in the skin of the african frog Hylambates maculatus

The skin of the African frog, Hylambates maculatus, contains large amounts of a caerulein-like peptide, which has been identified as Asn2, Leu5-caerulein. The cholecystokinetic activity of Hylambates-caerulein is very similar to that of caerulein.

Glu(OMe)2-litorin, the second bombesin-like peptide occurring in methanol extracts of the skin of the Australian frogLitoria aurea

The second bombesin-like peptide occurring in methanol extracts of the skin of the Australian frog Litoria aurea was isolated in a pure form and identified as Glu (OMe)2-litorin.

Purification and Micro Sequence Analysis of Active Peptides from Amphibian Skins

PEPTIDE PURIFICATION. In addition to the normally routine methods, we have applied the following techniques to solve some structural problems observed during the isolation of active peptides from amphibian skins: (i) isoelectric focusing in combination with electrophoresis to separate sauvagine I and II; (ii) reverse-phase HPLC to purify dermorphins and triptokinins; in particular, HPLC appears to be a versatile technique to isolate isocratically (on a / Bondapak C-18 column) caerulein from the analogue beta Asp3-caerulein (using as eluent 30% MeOH-10% MeCN in 0.02 M NH4OAc at pH 3.5), probably because of a different protonation of their aspartyl residues at the 3rd position; these results are in accordance with those obtained on HVPE at pH 2.7 (pyridine/glacial acetic acid/water 1/100/899 by vol.).

The Amino Acid Sequence of a Novel Decapeptide from the Skin of the Neotropical Frog Phyllomedusa Sauvagei

A novel decapeptide with the following structure L M Y Y T L P R P V ■ has been recently isolated from the methanol extracts of the fresh skins of Phyll. sauvagei (Tucuman, Argentina). The purification procedure involves: (i) chromatography on alkaline alumina column (the peptide is eluted with 90% ethanol); gel filtration on Bio-Gel P-4 and (iii) RP-HPLC [column, Li-Chrosorb RP-2 (10 /u) Merck; eluent, 34% ethanol-66% 0.1M HCOOH at pH 2.5 with NH4OH; flow rate, 0.7ml/min; detection UV at 215 nm; room temperature]. The peptide appears then homogeneous as judged by chromatography, including RP-HPLC, and several kinds of electrophoresis. The molecule has been analyzed for primary structure and the strategy employed is summarized in the scheme.