Unravelling the Skin Secretion Peptides of the Gliding Leaf Frog, Agalychnis spurrelli (Hylidae)

Frog skin secretions contain medically-valuable molecules, which are useful for the discovery of new biopharmaceuticals. The peptide profile of the skin secretion of Agalychnis spurrelli has not been investigated; therefore, the structural and biological characterization of its compounds signify an inestimable opportunity to acquire new biologically-active chemical scaffolds. In this work, skin secretion from this amphibian was analysed by molecular cloning and tandem mass spectrometry. Although the extent of this work was not exhaustive, eleven skin secretion peptides belonging to five peptide families were identified. Among these, we report the occurrence of two phyllokinins, and one medusin-SP which were previously reported in other related species. In addition, eight novel peptides were identified, including four dermaseptins, DRS-SP2 to DRS-SP5, one phylloseptin-SP1, and three orphan peptides. Phylloseptin-SP1 and dermaseptins-SP2 were identified in HPLC fractions based on their molecular masses determined by MALDI-TOF MS. Among the antimicrobial peptides, dermaseptin-SP2 was the most potent, inhibiting Escherichia coli, Staphylococcus aureus, and ORSA with a minimum inhibitory concentration (MIC) of 2.68 μM, and Candida albicans with an MIC of 10.71 μM, without haemolytic effects. The peptides described in this study represent but a superficial glance at the considerable structural diversity of bioactive peptides produced in the skin secretion of A. spurrelli.

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Synthesis and Characterization of Various Amino Acid Derived Thiohydantoins

Proceedings ◽

10.3390/ecsoc-22-05690 ◽

2018 ◽

Vol 9 (1) ◽

pp. 37

Author(s):

Petar Stanić ◽

Marija Živković ◽

Biljana Šmit

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Allyl Isothiocyanate ◽

Structural Diversity ◽

Biologically Active ◽

Reaction Conditions ◽

X Ray ◽

X Ray Crystallography ◽

Sulfur Containing

Hydantoins and their sulfur containing analogues, thiohydantoins, are cyclic ureides that have attracted huge attention ever since their discovery. Most of them are biologically active compounds and several points of structural diversity have made them very synthetically attractive. Although substituents can be introduced to the hydantoin nucleus, most substituted hydantoins are synthesized from substrates already containing these groups, while forming the hydantoin nucleus. This is a common route to the synthesis of hydantoins and one of them is employed in this study. A series of 3-allyl-2-thiohydantoins is synthesized from various α-amino acids in a reaction with allyl isothiocyanate. The substitution of the acquired thiohydantoin depends on the structure of the starting α-amino acid. The residual group of the α-amino acid becomes the substituent at the C5-position, while N-monosubstituted amino acids give rise to a substituent in the N1-position. The reaction is carried out in a two-step process and the reaction conditions generally depend on the nature of the amino acid itself. All thiohydantoins are obtained in a good yield and fully characterized by NMR and IR spectroscopy, as well as X-ray crystallography.

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Novel Immunomodulator FTY720 Is Phosphorylated in Rats and Humans To Form a Single Stereoisomer. Identification, Chemical Proof, and Biological Characterization of the Biologically Active Species and Its Enantiomer

Journal of Medicinal Chemistry ◽

10.1021/jm050242f ◽

2005 ◽

Vol 48 (16) ◽

pp. 5373-5377 ◽

Cited By ~ 114

Author(s):

Rainer Albert ◽

Klaus Hinterding ◽

Volker Brinkmann ◽

Danilo Guerini ◽

Constanze Müller-Hartwieg ◽

...

Keyword(s):

Active Species ◽

Biologically Active ◽

Biological Characterization ◽

Single Stereoisomer

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Chemical and Biological Characterization of Technetium(I) and Rhenium(I) Tricarbonyl Complexes with Dithioether Ligands Serving as Linkers for Coupling the Tc(CO)3and Re(CO)3Moieties to Biologically Active Molecules

Bioconjugate Chemistry ◽

10.1021/bc990162o ◽

2000 ◽

Vol 11 (3) ◽

pp. 414-424 ◽

Cited By ~ 62

Author(s):

H.-J. Pietzsch ◽

A. Gupta ◽

M. Reisgys ◽

A. Drews ◽

S. Seifert ◽

...

Keyword(s):

Biologically Active ◽

Biological Characterization

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Balteatide: A Novel Antimicrobial Decapeptide from the Skin Secretion of the Purple-Sided Leaf Frog,Phyllomedusa baltea

The Scientific World JOURNAL ◽

10.1155/2014/176214 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Lilin Ge ◽

Xiaole Chen ◽

Chengbang Ma ◽

Mei Zhou ◽

Xinping Xi ◽

...

Keyword(s):

Amino Acid ◽

Rational Design ◽

Frog Skin ◽

Biologically Active ◽

Single Amino Acid ◽

Haemolytic Activity ◽

Amino Acid Difference ◽

Amino Acid Residues ◽

Skin Secretion ◽

Skin Secretions

The skin secretions of Neotropical phyllomedusine leaf frogs have proven to be a rich source of biologically active peptides, including antimicrobials. The major families of antimicrobial peptides (AMPs) reported are the dermaseptins and phylloseptins and the minor families are the dermatoxins, phylloxins, plasticins, distinctins, and medusins. Here, we report a novel AMP of 10 amino acid residues (LRPAILVRIKamide), named balteatide, from the skin secretion of wild Peruvian purple-sided leaf frogs,Phyllomedusa baltea. Balteatide was found to exhibit a 90% sequence identity with sauvatide, a potent myotropic peptide from the skin secretion ofPhyllomedusa sauvagei. However, despite both peptides exhibiting only a single amino acid difference (I/T at position 9), sauvatide is devoid of antimicrobial activity and balteatide is devoid of myotropic activity. Balteatide was found to have differential activity against the Gram-positive bacterium,Staphylococcus aureus; the Gram-negative bacterium,Escherichia coli; and the yeast,Candida albicans, and unusual for phyllomedusine frog skin AMPs, was most potent (MIC 32 mg/L) against the yeast. Balteatide was also devoid of haemolytic activity up to concentrations of 512 mg/L. Phyllomedusine frog skin secretions thus continue to provide novel AMPs, some of which may provide templates for the rational design of new classes of anti-infective therapeutics.

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Characterization of photosystem II with the atomic-force microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130365 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1146-1147

Author(s):

Kathleen M. Marr ◽

Mary K. Lyon

Keyword(s):

Photosystem Ii ◽

Atomic Force Microscope ◽

Three Dimensional ◽

Biologically Active ◽

Atomic Force ◽

Freeze Etching ◽

Image Averaging ◽

Oxygen Evolving ◽

Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

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Phytoequivalence in the global marketplace for botanical products: chemical and biological characterization of Equisetum arvense extracts from America, Asia, and Europe

Planta Medica ◽

10.1055/s-0028-1083942 ◽

2008 ◽

Vol 74 (09) ◽

Author(s):

S Lee ◽

MC Carles ◽

J Hennell ◽

C Khoo ◽

S Govindaraghavan ◽

...

Keyword(s):

Equisetum Arvense ◽

Biological Characterization ◽

Global Marketplace ◽

Botanical Products

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Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽

10.32964/tj12.1.37 ◽

2013 ◽

Vol 12 (1) ◽

pp. 37-43 ◽

Cited By ~ 1

Author(s):

HANNU PAKKANEN ◽

TEEMU PALOHEIMO ◽

RAIMO ALÉN

Keyword(s):

Mass Transfer ◽

Molecular Mass ◽

Initial Phase ◽

Degradation Products ◽

Kraft Pulping ◽

Reaction Products ◽

Cooking Temperature ◽

Molecular Masses ◽

Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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