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1.
Zootaxa ; 5230(2): 153-178, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-37044851

ABSTRACT

With alarming frequency, significant collections in natural history museums have been destroyed or damaged through insurrections, cyclones, wars, fires, floods, or earthquakes particularly in the nineteenth century but continuing into the twentieth century with World War II bombings, fires, and earthquakes being the primary causes of loss in fifty-seven institutions across thirty countries. We review the loss or damage of museum collections globally, and their varied causes. We emphasize the benefits of dispersal of a sample of paratypes across institutions as an essential feature of taxonomic practice. We argue that museums do not own type material but are acting as perpetual custodians of type material on behalf of science and society in general, and that museums, therefore, have an obligation to minimize the risk to their collections. The significance of the loss of type material would be ameliorated if, when there are numerous paratypes or syntypes, members of a type series were distributed among several institutions. This is currently common practice but historically this was not always the case and might not be possible if only a single holotype is available. We also reaffirm the need for scientists around the globe to develop specific protocols to protect collections of biological and cultural materials from loss or damage from natural and human-created disasters now and into the future. We comment on recent moves to modify the Zoological Code of Nomenclature to allow the use of images as "type" material when describing new species with the image serving as a substitute for "physical" specimens deposited in museum collections. Although our focus is on herpetological collections, our particular interest and area of expertise, our observations apply broadly to all collections, including those of animals, plants, and anthropological or ethnographic material.


Subject(s)
Disasters , Museums , Humans , Animals , Natural History
2.
Peptides ; 71: 296-303, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26026377

ABSTRACT

The major mode of transmission of the human immunodeficiency virus (HIV) is by sexual intercourse. In the effort to halt the spread of HIV, one measure that holds great promise is the development of effective microbicides that can prevent transmission. Previously we showed that several amphibian antimicrobial peptides (AMPs) completely inhibit HIV infection of T cells while maintaining good viability of the T cell targets. These peptides also inhibited the transfer of HIV by dendritic cells (DCs) to T cells when added up to 8h after virus exposure. Here we report on the anti-HIV activity of 18 additional structurally related caerin 1 family peptides in comparison with our previous best candidate caerin 1.9. Nine peptides were equally effective or more effective in the inhibition of T cell infection and disruption of the HIV envelope as caerin 1.9. Of those nine peptides, three peptides (caerin 1.2, caerin 1.10, and caerin 1.20) exhibited excellent inhibition of HIV infectivity at low concentrations (12-25µM) and limited toxicity against target T cells and endocervical epithelial cells. There was a direct correlation between the effectiveness of the peptides in disruption of the viral envelope and their capacity to inhibit infection. Thus, several additional caerin 1 family peptides inhibit HIV infection have limited toxicity for vaginal epithelial cells, and would be good candidates for inclusion in microbicide formulations.


Subject(s)
Amphibian Proteins/pharmacology , Antimicrobial Cationic Peptides/pharmacology , HIV Infections/drug therapy , HIV-1 , T-Lymphocytes/virology , Dose-Response Relationship, Drug , Humans , T-Lymphocytes/metabolism
3.
Article in English | MEDLINE | ID: mdl-23665109

ABSTRACT

The dorsal adhesive secretion of the frog Notaden bennetti and the prey-capture "slime" ejected by Euperipatoides sp. velvet worms look and handle similarly. Both consist largely of protein (55-60% of dry weight), which provides the structural scaffold. The major protein of the onychophoran glue (Er_P1 for Euperipatoides rowelli) and the dominant frog glue protein (Nb-1R) are both very large (260-500 kDa), and both give oddly "turbulent" electrophoresis bands. Both major proteins, which are rich in Gly (16-17 mol%) and Pro (7-12 mol%) and contain 4-hydroxyproline (Hyp, 4 mol%), have the composition of intrinsically unstructured proteins. Their propensities for elastomeric or amyloid structures are discussed in light of Er_P1's large content of intrinsically disordered long tandem repeats. The low carbohydrate content of both glues is consistent with conventional protein glycosylation, which in the N. bennetti adhesive was explored by 2D PAGE. The N-linked sugars of Nb-1R appear to prevent inappropriate self-aggregation. Some peptide sequences from Nb-1R are presented. Overall, there are enough similarities between the frog and the velvet worm glues to suspect that they employ related mechanisms for setting and adhesion. A common paradigm is proposed for amphibian and onychophoran adhesives, which, if correct, points to convergent evolution.


Subject(s)
Anura/metabolism , Exudates and Transudates/chemistry , Invertebrates/metabolism , Proteins/genetics , Skin/chemistry , Adhesiveness , Amino Acid Sequence , Animals , Base Sequence , Blotting, Western , Electrophoresis, Gel, Two-Dimensional , Glycosylation , Linear Models , Molecular Sequence Data , Scattering, Radiation , Sequence Analysis, DNA , Species Specificity
4.
Peptides ; 37(1): 174-88, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22771617

ABSTRACT

A previous review summarized research prior to 2004 carried out on the bioactive host-defense peptides contained in the skin secretions of Australian anurans (frogs and toads). This review covers the extension of that research from 2004 to 2012, and includes membrane-active peptides (including antibacterial, anticancer, antifungal and antiviral peptides) together with the mechanisms by which these peptides interact with model membranes, peptides that may be classified as "neuropeptides" (including smooth muscle active peptides, opioids and immunomodulators) and peptides which inhibit the formation of nitric oxide from neuronal nitric oxide synthase. The review discusses the outcome of cDNA sequencing of signal-spacer-active peptides from an evolutionary viewpoint, and also lists those peptides for which activities have not been found to this time.


Subject(s)
Amphibian Proteins/chemistry , Anti-Infective Agents/chemistry , Antimicrobial Cationic Peptides/chemistry , Anura/genetics , Oligopeptides/chemistry , Amino Acid Sequence , Amphibian Proteins/genetics , Amphibian Proteins/pharmacology , Animals , Anti-Infective Agents/pharmacology , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/pharmacology , Australia , Evolution, Molecular , Humans , Molecular Sequence Data , Muscle Contraction/drug effects , Neuropeptides/chemistry , Neuropeptides/genetics , Neuropeptides/pharmacology , Nitric Oxide Synthase Type I/antagonists & inhibitors , Oligopeptides/genetics , Oligopeptides/pharmacology , Pheromones/chemistry , Pheromones/genetics , Protein Structure, Secondary
5.
Rapid Commun Mass Spectrom ; 25(12): 1735-40, 2011 Jun 30.
Article in English | MEDLINE | ID: mdl-21598333

ABSTRACT

The Kyn-containing peptide FP-Kyn-L(NH(2)) is an unusual minor component of the skin peptide profile of the Australian red tree frog Litoria rubella collected from an area within a 20 kilometre radius of Alice Springs in central Australia. The structure was determined by electrospray mass spectrometry and synthesis. The major component of the skin secretion is the analogous tryptophyllin peptide FPWL(NH(2)). Both peptides show opioid activity at 10(-7) M, and are likely to act via the µ opioid receptor.


Subject(s)
Analgesics, Opioid/chemistry , Kynurenine/chemistry , Oligopeptides/chemistry , Skin/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Animals , Anura , Australia , Kynurenine/analysis , Receptors, Opioid/chemistry , Sequence Analysis, Protein , Skin/metabolism
6.
Peptides ; 32(1): 161-72, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20932866

ABSTRACT

Host defense peptides of 35 species of Australian frogs from the hylids Cyclorana and Litoria, and the myobatrachids Crinia, Limnodynastes and Uperoleia have been identified. The biological activities of the majority of these peptides have been determined and include hormones, neuropeptides, opioids, immunomodulators, membrane active peptides [including antimicrobial, anticancer, antiviral (enveloped viruses like HIV and Herpes) and antifungal peptides], neuronal nitric oxide synthase inhibitors, pheromones and individual peptides with other specific activities. The host defense peptide skin profile can be diagnostic at both the species and higher taxonomic levels; for example, species of Crinia, Litoria and Uperoleia each produce quite different types of peptides. Species of Cyclorana and Limnodynastes are more difficult to characterize by skin peptides alone: species of both genera produce similar peptides with no apparent activity. The skin peptide profiles of frogs from the genera Crinia, Litoria and Uperoleia may be used together with morphological and cognate methods, to differentiate between sub-species and even different population clusters of the same species. Nucleotide sequencing of cDNAs of precursors (pre-pro peptides) of bioactive peptides from the skin glands of various species of the genus Litoria show that the majority of these peptides originated from a single ancestor gene before the break away of Australia from Gondwana. The exceptions are the caerulein neuropeptides {e.g. caerulein [pEQDY(SO(3)H)TGWMDF(NH(2))]} which have a different origin to that of other Litoria peptides. Disulfide containing peptides from skin glands of species of Crinia show a different evolutionary route to peptides from species of Litoria.


Subject(s)
Anura/classification , Anura/genetics , Evolution, Molecular , Peptides/chemistry , Peptides/genetics , Skin/metabolism , Amino Acid Sequence , Amphibian Proteins/genetics , Amphibian Proteins/metabolism , Animals , Anura/anatomy & histology , Australia , Cloning, Molecular , DNA, Complementary/chemistry , Genetic Variation , Molecular Sequence Data
7.
J Biomed Mater Res A ; 93(2): 429-41, 2010 May.
Article in English | MEDLINE | ID: mdl-19569213

ABSTRACT

When provoked, Notaden bennetti frogs secrete a proteinaceous exudate, which rapidly forms a tacky and elastic glue. This material has potential in biomedical applications. Cultured cells attached and proliferated well on glue-coated tissue culture polystyrene, but migrated somewhat slower than on uncoated surfaces. In organ culture, dissolved glue successfully adhered collagen-coated perfluoropolyether lenses to debrided bovine corneas and supported epithelial regrowth. Small pellets of glue implanted subcutaneously into mice were resorbed by surrounding tissues, and all of the animals made a full recovery. An initial but transient skin necrosis at the implant site was probably caused by some of the potentially toxic metabolites present in the frog secretion; these include sterols and carotenoids, as well as fatty alcohols, aldehydes, ketones, acids, and aromatic compounds. Removal of the carotenoid pigments did not significantly alter the glue's material properties. In contrast, peroxidase treatment of dissolved glue introduced unnatural crosslinks between molecules of the major protein (Nb-1R) and resulted in the formation of a soft hydrogel, which was very different to the original material.


Subject(s)
Adhesives , Anura , Biocompatible Materials , Acetone/chemistry , Adhesives/chemistry , Adhesives/metabolism , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/metabolism , Cattle , Cell Adhesion/physiology , Cell Culture Techniques , Cell Movement/physiology , Cells, Cultured , Cornea/metabolism , Endotoxins/metabolism , Female , Gas Chromatography-Mass Spectrometry , Materials Testing , Mice , Mice, Inbred BALB C , Solvents/chemistry , Surface Properties , Tissue Culture Techniques
8.
Rapid Commun Mass Spectrom ; 23(17): 2628-36, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19642086

ABSTRACT

Positive and negative ion electrospray mass spectrometry together with Edman sequencing (when appropriate) has been used to sequence the host-defence peptides secreted from skin glands of the tree frog Litoria peronii. The peptide profiles are different in winter and summer. In winter, the frog produces small amounts of the known caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL-NH(2)] (a wide-spectrum antibiotic) and caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA-OH], a narrow-spectrum antibiotic and an inhibitor of neuronal nitric oxide synthase. The major peptides produced throughout the year are the pGlu-containing peroniins 1.1 to 1.5 (e.g. peroniin 1.1 [pEPWLPFG-NH(2)], a smooth muscle contractor from 10(-7) M), and caerulein [pEQDY(SO(3)H)TGWMDF-NH(2)], a known and potent smooth muscle contractor from 10(-10) M. There are also some precursors to the peroniin 1 peptides, only detected in the skin secretion in summer, which are inactive and appear to be all (or part) of the spacer peroniin 1 peptides, e.g. peroniin 1.1b [SEEEKRQPWLPFG-NH(2)]. There are three members of the Litoria peronii Group of tree frogs classified in Australia, namely, L. peronii, L. rothii and L.tyleri. A comparison of the skin peptide profiles of L. peronii with those reported previously for L. rothii suggests that either these two species of tree frog are not as closely related as determined previously on morphological grounds, or that skin peptide divergence in tree frogs of this Group is more extensive than in others that have been studied.


Subject(s)
Amphibian Proteins/chemistry , Anti-Bacterial Agents/chemistry , Antimicrobial Cationic Peptides/chemistry , Anura/metabolism , Skin/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Amino Acid Sequence , Amphibian Proteins/metabolism , Animals , Anti-Bacterial Agents/metabolism , Antimicrobial Cationic Peptides/metabolism , Bacteria/drug effects , Molecular Sequence Data , Seasons , Skin/metabolism
9.
Rapid Commun Mass Spectrom ; 23(8): 1189-95, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19291693

ABSTRACT

Many species of frogs of the genus Litoria secrete bioactive peptides from their skin glands. These peptides are normally host-defence compounds and may have one, or more of the following activities; smooth muscle contraction, analgesic, antimicrobial, antiviral, lymphocyte proliferator (immunomodulator) and neuronal nitric oxide synthase (nNOS) inactivation. Two frog species of the Litoria rubella Group that have been studied before, namely, Litoria electrica and Litoria rubella, are different from other species of the genus Litoria in that they produce small peptides that show neither membrane, lymphocyte nor nNOS activity. In this study we have used electrospray mass spectrometry together with Edman sequencing to identify eight skin peptides of the third member of this Group, Litoria dentata: surprisingly, none of these peptides show activity in our biological screening program. However, two major peptides (FPWL-NH(2) and FPWP-NH(2)) from L. electrica and L. rubella are opioids at the micromolar concentration.


Subject(s)
Analgesics, Opioid/analysis , Anura , Oligopeptides/analysis , Sequence Analysis, Protein/methods , Skin/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Amino Acid Sequence , Animals , Molecular Sequence Data , Oligopeptides/chemistry
10.
J Shoulder Elbow Surg ; 18(4): 639-45, 2009.
Article in English | MEDLINE | ID: mdl-19250843

ABSTRACT

SUMMARY: Rotator cuff tendons are typically reattached to the proximal humerus using transosseous sutures or suture anchors. Their primary mode of failure is at the tendon-bone interface. We investigated the addition of a novel adhesive secreted from a species of Australian frog (Notaden bennetti) to different methods of rotator cuff repair. We hypothesized that the addition of frog glue would increase the strength of the repaired rotator cuff construct. Three techniques were used to repair 42 fresh frozen sheep infraspinatus tendons with a mattress stitch configuration: transosseous sutures; 2 traditional metallic suture anchors with 1 suture per anchor, and 2 knotless metallic anchors with 1 suture per anchor. In each group, 7 shoulders were repaired with the addition of frog glue to the infraspinatus "footprint," whereas 7 were used as control with no adhesive. Failure occurred in all constructs at the tendon-bone-suture interface. Repair with suture anchors was stronger than with sutures through bone (P < .05). Frog glue significantly increased the load to failure, total energy required for failure, and maximum energy at failure in all repair techniques (P < .01). A 2-fold increase occurred in load to failure of the 2 common anchor types (143 +/- 8 and 165 +/- 20 N). The load to failure for the transosseous repair (86 +/- 8 N) increased 1.7-fold. The addition of an adhesive to the tendon-bone-suture interface significantly enhances ultimate load and total energy required to failure in 3 types of rotator cuff repair. The unique properties of this frog glue (strong, flexible and sets in water) may ultimately lead to its use as an adjunct to rotator cuff repair in humans. LEVEL OF EVIDENCE: Basic science study.


Subject(s)
Rotator Cuff/surgery , Suture Anchors , Tensile Strength , Tissue Adhesives/therapeutic use , Animals , Anura , Biomechanical Phenomena , Cadaver , Combined Modality Therapy , Disease Models, Animal , Models, Animal , Probability , Sensitivity and Specificity , Sheep , Shoulder/surgery , Stress, Mechanical , Suture Techniques
11.
Rapid Commun Mass Spectrom ; 22(20): 3207-16, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18803332

ABSTRACT

The glandular skin secretion of the Eastern Dwarf Tree Frog Litoria fallax contains nine peptides named fallaxidins. The sequences of these peptides were elucidated using a combination of positive and negative electrospray mass spectrometry together with Edman sequencing. Among these peptides are: (i) fallaxidins 1.1 and 2.1 which have the sequences YFPIPI-NH2 and FWPFM-NH2. The activities of these peptides are unknown, but it has been shown that they are not smooth muscle active, opioids or antimicrobially active, nor do they effect proliferation of lymphocytes; (ii) two weakly active antibiotics, fallaxidins 3.1 and 3.2 (e.g. fallaxidin 3.1, GLLDLAKHVIGIASKL-NH2), and a moderately active antibiotic fallaxidin 4.1 (GLLSFLPKVIGVIGHLIHPPS-OH). Fallaxidin 4.1 has an unusual sequence for an antibiotic, containing three Pro residues together with a C-terminal CO2H group. cDNA cloning has confirmed the identity of the nine isolated peptides from L. fallax, together with five additional peptides not detected in the peptide profile. The pre-regions of the nine preprofallaxidins are conserved and similar to those of the caerin peptides from L. caerulea and L. splendida, suggesting that the fallaxidin and caerin peptides, although significantly different in sequence, originated from a common ancestor gene.


Subject(s)
Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/analysis , Antimicrobial Cationic Peptides/pharmacology , Anura/metabolism , DNA, Complementary/genetics , Skin/chemistry , Amino Acid Sequence , Animals , Cloning, Molecular , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Molecular Sequence Data , Peptides/genetics , Peptides/isolation & purification , Peptides/pharmacology , Skin/metabolism , Spectrometry, Mass, Electrospray Ionization
12.
Regul Pept ; 151(1-3): 80-7, 2008 Nov 29.
Article in English | MEDLINE | ID: mdl-18601958

ABSTRACT

The skin secretions of Crinia signifera, C. riparia and C. deserticola contain bioactive disulfide-containing peptides. Signiferin 1 (RLCIPYIIPC-OH) from C. signifera and C. deserticola) contracts smooth muscle at a concentration of 10(-9) M, and effects proliferation of lymphocytes at 10(-6) M. In contrast, riparin 1.1 (RLCIPVIFC-OH) and riparin 1.2 (FLPPCAYKGTC-OH) from C. riparia show lymphocyte activity but do not contract smooth muscle. The lymphocyte and smooth muscle activities involve CCK2R. 3D structures of signiferin 1 and riparin 1.1 have been established using 2D NMR methods: these studies show significant differences in the shapes of the disulfide rings and with the orientations of the N-terminal residues. cDNA cloning establishes that the pre sections of the precursor pre-pro-riparin 1.4-1.6 peptides are different from the conserved pre regions of disulfide-containing antimicrobial peptides from species of the genus Rana found in the northern hemisphere and caerin antimicrobial peptides isolated from Australian tree frogs of the genus Litoria. This suggests that (i) either that riparins 1 have converged to similar structure and function to the ranid and hyloid prepropeptides which were lost initially from the myobatrachid lineage, or (ii) the prepropeptides in all three groups were derived from a single ancestral form that has remained relatively conserved in the hyloid and ranoid lineages but has undergone substantial divergent evolution in the myobatrachids.


Subject(s)
Amphibian Proteins/chemistry , Amphibian Proteins/metabolism , Anura/physiology , Neuropeptides/chemistry , Neuropeptides/metabolism , Peptides/chemistry , Peptides/metabolism , Amino Acid Sequence , Amphibian Proteins/genetics , Amphibian Proteins/pharmacology , Animals , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/metabolism , Antimicrobial Cationic Peptides/pharmacology , Anura/genetics , Base Sequence , Cloning, Molecular , DNA Primers/genetics , DNA, Complementary/genetics , Disulfides/chemistry , Evolution, Molecular , Lymphocyte Activation/drug effects , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Models, Molecular , Molecular Sequence Data , Molecular Structure , Muscle Contraction/drug effects , Neuropeptides/genetics , Neuropeptides/pharmacology , Nitric Oxide Synthase Type I/antagonists & inhibitors , Peptides/genetics , Peptides/pharmacology , Protein Conformation , Skin/metabolism
13.
FEBS J ; 273(15): 3511-9, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16824041

ABSTRACT

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. Phylogenetic analysis of mitochondrial DNA sequences established the female parent to be L. splendida. The peptide profile of the hybrid frogs included the neuropeptide caerulein, four antibiotics of the caerin 1 family and several neuronal nitric oxide synthase inhibitors of the caerin 1 and 2 classes of peptides. The skin secretions of the hybrids contained some peptides common to only one parent, some produced by both parental species, and four peptides expressed by the hybrids but not the parental species.


Subject(s)
Hybridization, Genetic , Peptides/metabolism , Skin/metabolism , Animals , Anura , Cloning, Molecular , DNA, Complementary , Peptides/chemistry , Peptides/pharmacology , Phylogeny , Species Specificity
15.
Toxicon ; 47(6): 664-75, 2006 May.
Article in English | MEDLINE | ID: mdl-16554081

ABSTRACT

The skin secretion of the Dainty Green Tree Frog Litoria gracilenta contains 16 peptides, which protect the animal from predators, both large and small. A combination of negative and positive ion electrospray mass spectrometry together with Lys-C enzymic digest and Edman sequencing identifies three new wide-spectrum caerin 1 antibiotics, namely Caerin 1.17 [GLFSVLGSVAKHLLPHVAPIIAEKL-NH2], Caerin 1.18 [GLFSVLGSVAKHLLPHVVPVIAEKL-NH2], and Caerin 1.19 [GLFKVLGSVAKHLLPHVAPIIAEKL-NH2], and a narrow spectrum antibiotic Caerin 3.5 [GLWEKVKEKANELVSGIVEGVK-NH2].


Subject(s)
Amphibian Proteins/chemistry , Anti-Infective Agents/analysis , Antimicrobial Cationic Peptides/chemistry , Anura , Skin/metabolism , Spectrometry, Mass, Electrospray Ionization/methods , Amino Acid Sequence , Animals , Chromatography, High Pressure Liquid , Molecular Sequence Data
16.
Rapid Commun Mass Spectrom ; 20(5): 797-803, 2006.
Article in English | MEDLINE | ID: mdl-16470724

ABSTRACT

A combination of positive and negative ion electrospray mass spectrometry (ES-MS) together with automated Edman sequencing has been used to determine the amino acid sequences of the host-defence peptides from the skin glands of the froglet Crinia riparia. The peptides are called riparins. Of the eight peptides isolated, five are neuropeptides containing intramolecular disulfide linkages; e.g. the major peptide riparin 1.4 (FFLPPCAYKGTC-OH). Positive ion ES-MS identifies the five residues of riparin 1.4 outside the disulfide moiety, but provides no information on the sequence within the disulfide ring. In contrast, the negative ion dissociations of the [M-H]- ion of riparin 1.4 identify the --S-S-- link by loss of H2S2 from the [M-H]- ion, and also provide the sequence within the disulfide unit. Other peptides are riparin 2.1 [(IIEKLVNTALGLLSGL-NH2), a narrow-spectrum antibiotic], signiferin 3.1 [(GIAEFLNYIKSKA-NH2), an nNOS inhibitor] and riparin 5.1 [IVSYPDDAGEHAHKMG-NH2], which shows no neuropeptide, antibiotic or nNOS activity.


Subject(s)
Neuropeptides/analysis , Ranidae/metabolism , Skin/metabolism , Spectrometry, Mass, Electrospray Ionization/methods , Amino Acid Sequence , Animals , Chromatography, High Pressure Liquid , Molecular Sequence Data , Sequence Analysis, Protein , Skin/chemistry
17.
Oecologia ; 146(4): 531-40, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16205955

ABSTRACT

Many species of amphibians in the wet tropics of Australia have experienced population declines linked with the emergence of a skin-invasive chytrid fungus, Batrachochytrium dendrobatidis. An innate defense, antimicrobial peptides produced by granular glands in the skin, may protect some species from disease. Here we present evidence that supports this hypothesis. We tested ten synthesized peptides produced by Australian species, and natural peptide mixtures from five Queensland rainforest species. Natural mixtures and most peptides tested in isolation inhibited growth of B. dendrobatidis in vitro. The three most active peptides (caerin 1.9, maculatin 1.1, and caerin 1.1) were found in the secretions of non-declining species (Litoria chloris, L. caerulea, and L. genimaculata). Although the possession of a potent isolated antimicrobial peptide does not guarantee protection from infection, non-declining species (L. lesueuri and L. genimaculata) inhabiting the rainforest of Queensland possess mixtures of peptides that may be more protective than those of the species occurring in the same habitat that have recently experienced population declines associated with chytridiomycosis (L. nannotis, L. rheocola, and Nyctimystes dayi). This study demonstrates that in vitro effectiveness of skin peptides correlates with the degree of decline in the face of an emerging pathogen. Further research is needed to assess whether this non-specific immune defense may be useful in predicting disease susceptibility in other species.


Subject(s)
Antifungal Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Anura , Chytridiomycota/drug effects , Dermatomycoses/immunology , Animals , Antifungal Agents/isolation & purification , Antimicrobial Cationic Peptides/isolation & purification , Australia , Chytridiomycota/immunology , Dermatomycoses/veterinary , Microbial Sensitivity Tests , Population , Queensland
18.
Biomacromolecules ; 6(6): 3300-12, 2005.
Article in English | MEDLINE | ID: mdl-16283759

ABSTRACT

When provoked, Notaden bennetti frogs secrete an exudate which rapidly forms a tacky elastic solid ("frog glue"). This protein-based material acts as a promiscuous pressure-sensitive adhesive that functions even in wet conditions. We conducted macroscopic tests in air to assess the tensile strength of moist glue (up to 78 +/- 8 kPa) and the shear strength of dry glue (1.7 +/- 0.3 MPa). We also performed nanomechanical measurements in water to determine the adhesion (1.9-7.2 nN or greater), resilience (43-56%), and elastic modulus (170-1035 kPa) of solid glue collected in different ways. Dry glue contains little carbohydrate and consists mainly of protein. The protein complement is rich in Gly (15.8 mol %), Pro (8.8 mol %), and Glu/Gln (14.1 mol %); it also contains some 4-hydroxyproline (4.6 mol %) but no 5-hydroxylysine or 3,4-dihydroxyphenylalanine (L-Dopa). Denaturing gel electrophoresis of the glue reveals a characteristic pattern of proteins spanning 13-400 kDa. The largest protein (Nb-1R, apparent molecular mass 350-500 kDa) is also the most abundant, and this protein appears to be the key structural component. The solid glue can be dissolved in dilute acids; raising the ionic strength causes the glue components to self-assemble spontaneously into a solid which resembles the starting material. We describe scattering studies on dissolved and solid glue and provide microscopy images of glue surfaces and sections, revealing a porous interior that is consistent with the high water content (85-90 wt %) of moist glue. In addition to compositional similarities with other biological adhesives and well-known elastomeric proteins, the circular dichroism spectrum of dissolved glue is almost identical to that for soluble elastin and electron and scanning probe microscopy images invite comparison with silk fibroins. Covalent cross-linking does not seem to be necessary for the glue to set.


Subject(s)
Adhesives/chemistry , Anura/metabolism , Biocompatible Materials/chemistry , Elastomers/chemistry , Macromolecular Substances/chemistry , Adhesiveness , Animals , Carbohydrates/chemistry , Circular Dichroism , Cross-Linking Reagents/pharmacology , Dihydroxyphenylalanine/chemistry , Electron Probe Microanalysis , Glycine/chemistry , Hydroxylysine/chemistry , Hydroxyproline/chemistry , Light , Microscopy, Scanning Probe , Molecular Weight , Proline/chemistry , Proteins/chemistry , Scattering, Radiation , Stress, Mechanical , Tensile Strength , Tissue Adhesions , X-Rays
19.
J Virol ; 79(18): 11598-606, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16140737

ABSTRACT

Topical antimicrobicides hold great promise in reducing human immunodeficiency virus (HIV) transmission. Amphibian skin provides a rich source of broad-spectrum antimicrobial peptides including some that have antiviral activity. We tested 14 peptides derived from diverse amphibian species for the capacity to inhibit HIV infection. Three peptides (caerin 1.1, caerin 1.9, and maculatin 1.1) completely inhibited HIV infection of T cells within minutes of exposure to virus at concentrations that were not toxic to target cells. These peptides also suppressed infection by murine leukemia virus but not by reovirus, a structurally unrelated nonenveloped virus. Preincubation with peptides prevented viral fusion to target cells and disrupted the HIV envelope. Remarkably, these amphibian peptides also were highly effective in inhibiting the transfer of HIV by dendritic cells (DCs) to T cells, even when DCs were transiently exposed to peptides 8 h after virus capture. These data suggest that amphibian-derived peptides can access DC-sequestered HIV and destroy the virus before it can be transferred to T cells. Thus, amphibian-derived antimicrobial peptides show promise as topical inhibitors of mucosal HIV transmission and provide novel tools to understand the complex biology of HIV capture by DCs.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Dendritic Cells/drug effects , Dendritic Cells/virology , HIV Infections/prevention & control , HIV/drug effects , T-Lymphocytes/drug effects , T-Lymphocytes/virology , Amino Acid Sequence , Amphibians/genetics , Amphibians/immunology , Animals , Antimicrobial Cationic Peptides/genetics , Cells, Cultured , HIV Infections/transmission , Humans , Immunity, Innate , In Vitro Techniques , Molecular Sequence Data , Skin/immunology
20.
Rapid Commun Mass Spectrom ; 19(18): 2716-24, 2005.
Article in English | MEDLINE | ID: mdl-16124032

ABSTRACT

The secretion from the dorsal glands of the frog Litoria rothii contains a series of new peptides including rothein 1 (SVSNIPESIGF-OH, a neuropeptide which contracts smooth muscle), a number of inactive rothein 2 and 3 peptides (e.g. rothein 2.1, AGGLDDLLEPVLNSADNLVHGL-OH), and a new proline rich peptide, named rothein 4.1 (AEILFGDVRPPWMPPPIFPEMP-OH), which shows neither antimicrobial nor neuronal nitric oxide synthase (nNOS) activity. Two known neuropeptides of the caerulein family [e.g. caerulein, pEQDY(SO3)TGWMDF-NH2] together with a series of known caerin 1 antibiotic and nNOS-inhibiting peptides (e.g. caerin 1.1, GLLSVLGSVAKHVLPHVVPVIAEHL-NH2) were also identified. Positive ion electrospray mass spectrometry (ES-MS) was used as the primary method to investigate the sequences of the new peptides. Negative ion ES-MS was used to fill in any gaps in the positive ion data and, finally, Edman automated sequencing was used to differentiate between Leu and Ile and to confirm the sequences determined by mass spectrometry.


Subject(s)
Peptides/chemistry , Ranidae , Sequence Analysis, Protein/methods , Skin/chemistry , Skin/metabolism , Amino Acid Sequence , Animals , Molecular Sequence Data , Spectrometry, Mass, Electrospray Ionization
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