J M Conlon

..aureus. Cladistic analysis based upon the amino acid sequences of the brevinin-2 peptides from Asian frogs provides evidence for sister taxon relationships between O. hosii and O. livida and between H. picturata and H. güntheri...

..The analogue shows potential for treatment of nosocomial pulmonary infections caused by bacteria that have developed resistance to commonly used antibiotics...

..okinavana and R. tsushimensis. These conclusions are consistent with previous analyses based upon allozyme variations and comparisons of the nucleotide sequences of mitochondrial genes...

..grahami antimicrobial peptides suggest a close relationship of this species with the Japanese pond frogs R. nigromaculata and R. porosa brevipoda...

..The peptide therefore represents a candidate for drug development...

..The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity...

..L. warszewitschii is most closely related to the Central American species Lithobates tarahumarae and Lithobates vaillanti...

..The data emphasize that amino acid sequences of antimicrobial peptides in skin secretions may be used to infer taxonomic and phylogenetic relationships between species of ranid frogs...

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..Our data support the placement of R. virgatipes in the Aquarana and indicate a closer phylogenetic relationship of R. virgatipes with R. septentrionalis than with R. catesbeiana, R. clamitans and R. grylio...

..The data show that the synthesis of dermal peptides that may play a role in defense against predators arose early in the evolution of anurans...

..However, the reduction in alpha-helicity produced by the D-amino acid substitutions resulted in analogs with reduced potencies against Gram-positive bacteria and against C. albicans...

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..While the production of dermal cytolytic peptides may offer definite evolutionary advantage to anurans, their precise biological function, for example during metamorphosis, may need to be re-evaluated...

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..The data indicate a close phylogenetic relationship between R. chaochiaoensis and R. japonica but demonstrate that the species are not conspecific...

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..The data suggest a strategy of selective increases in cationicity concomitant with decreases in helicity and hydrophobicity in the transformation of naturally-occurring antimicrobial peptides into non-toxic therapeutic agents...

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..aurora form a clade that is distinct from one containing R. draytonii, R. boylii, and R. luteiventris. This conclusion is consistent with previous analyses based upon comparisons of the nucleotide sequences of mitochondrial genes...

..The limiting factor in the time taken to isolate a peptide is usually the speed at which assays to detect the peptide can be performed, but purifications can generally be accomplished within 1 or 2 weeks...

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..Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment...

..This component contains an Ala-Met bond that constitutes the scissile bond in the selective elastase inhibitor, elafin but the peptide did not inhibit pancreatic elastase at concentrations up to 100 microM...

..Ocellatin-L2 was devoid of antimicrobial and hemolytic activity but also showed significant activity in stimulating insulin release from BRIN-BD11 cells (181% of basal rate at 3 microM)...

..heckscheri and R. grylio and a close, but less well defined, phylogenetic relationship between R. okaloosae and R. clamitans...

..t. okiensis but not R. t. tagoi. The data provide evidence to support the proposal that R. t. tagoi and R. t. okiensis should be regarded as separate species (R. tagoi and R. okiensis) rather than conspecific subspecies...

..These examples point to a limited although potentially valuable role for granin-derived peptides as tumor markers...

..Two members of the ranatuerin-2 family and one member of the temporin family were also isolated from the secretions but showed relatively low potency against the three microorganisms tested...

..coli (MIC=50microM) and S. aureus (MIC=50microM). In contrast to brevinin-1BLc, ranatuerin-2Ya showed appreciably greater cytolytic activity against HepG2 cells (LC(50)=20microM) than against erythrocytes (LC(50)>100microM)...

..However, at non-cytotoxic concentrations (<or=8 microM), MRP did not protect HeLa cells from cell death produced by human rhinovirus type 2 infection...

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..This study has illustrated the power of electrospray mass spectrometry for the rapid and reliable identification of peptides in chromatographic fractions without the need to use radioimmunoassay, radioreceptor assay or bioassay...

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..Cladistic analysis based upon the primary structures of brevinin-1 peptides indicates a close phylogenetic relationship between L. chiricahuensis, L. onca, and L. yavapaiensis...

..pretiosa may be pivotal in defending the species against environmental pathogens such as B. dendrobatidis...

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..amieti lineage. However, the very low antimicrobial activity of the magainin-AM1 and PGLa-AM2 paralogs suggests the possibility that certain peptides may have evolved toward a new, as yet undetermined, function (neofunctionalization)...

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..NH(2)) and temporin-1PRb (ILPILGNLLNSLL.NH(2)) that atypically lacked basic amino acid residues and showed only very weak antimicrobial and hemolytic activity...

..The minimum inhibitory concentration of the peptide, termed brevinin-1 Da, against the Gram-positive bacterium Staphylococcus aureus was 7 microM and against the Gram-negative bacterium Escherichia coli was 30 microM...

..The data indicate that the host defence strategy of using antimicrobial peptides in skin secretions arose early in the evolution of anurans...

..Its biological function remains to be established. The primary structures of the antimicrobial peptides are consistent with a close phylogenetic relationship between R. aurora, Rana boylii and Rana luteiventris...

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..The data indicate a close phylogenetic relationship between L. onca and L. yavapaiensis but suggest that they are not conspecific species...

..Individual peptides with activity are purified to near homogeneity by further chromatography on butylsilyl-(C(4)) and diphenylmethylsilyl-silica columns and characterized structurally by automated Edman degradation and mass spectrometry...

..01) against all strains. The data demonstrate that [Lys-8] ranatuerin-1 shows potential as a candidate for drug development...

..5-25 microM) and its Lys4-substituted analog (MIC= 6 microM), although non-ESBL isolates of this organism were resistant to these peptides (MIC> 100 microM)...

..Phylogenetic analysis based upon the amino acid sequences of 47 brevinin-2 peptides from 17 Asian species belonging to the family Ranidae provides support for the placement of H. erythraea in the genus Hylarana...

..The use of mixtures of synthetic peptides of appropriate molecular mass as calibration standards enables mass determination to a high degree of precision...

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..05) improved glucose tolerance following a intraperitoneal injection of glucose, thereby demonstrating that the peptide shows potential for development into a therapeutically valuable agent for the treatment of Type 2 diabetes...

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..Temporin-1DRa was without effect. The temporins at 10(-7) M had no effect on intracellular calcium concentrations suggesting that they stimulate insulin release via a K(ATP) channel- independent pathway...

..CPF-B1 was active against clinical isolates of the nosocomial pathogens, methicillin-resistant S. aureus (MRSA) and multidrug-resistant Acinetobacter baumannii (MDRAB) with MIC values in the range 4-8 microM...

..Species names and assignments to genera may be obtained from Amphibian Species of the World Electronic Database, accessible at http://research.amnh.org/herpetology/amphibia/index.php. American Museum of Natural History, New York, USA...

..Fallaxin is replaced by ocellatin-F1, pentadactylin by ocellatin-P1, laticeptin by ocellatin-L1, syphaxin by ocellatin-S1, and the paralogs from L. validus are termed ocellatin-V1, -V2, and -V3...

..No evidence was found for the presence of VP in the uterus so that, if the hormone is involved in a stimulatory action on this tissue, it probably acts via an endocrine mechanism...

..It is proposed that the distribution and amino acid sequences of skin antimicrobial peptides may be useful markers for taxonomic classification of particular sub-populations and for an understanding of phylogenetic interrelationships...

..This structural information will facilitate the design of novel therapeutic agents based upon the ranatuerin-2CSa structure with improved antimicrobial potencies but decreased cytolytic activities against mammalian cells...

..Because tilapia islets are exceedingly resistant to hypoxia by mammalian standards, transgenic tilapia islets should be ideal for xenotransplantation using immunoisolation techniques...

..However, genes encoding sodefrin were found to be expressed in all the specimens sampled...

..The data provide further evidence that histones play a role in the defense against microorganisms...

..The peptides did not inhibit the growth of Escherichia coli or Staphylococcus aureus and were inactive on hamster vascular or gastric smooth muscle preparations so that their biological functions, if any, remain to be established...

..Differences in potency due to amino acid substitution suggest that ability to penetrate membranes and form an alpha-helical structure is important for their effectiveness against this pathogen...

..The data suggest that protease inhibitors in skin secretions may play a role complementary to cationic, amphipathic alpha-helical peptides in protecting anurans from invasions by microorganisms...

..Therefore, the observed susceptibility of these frogs to this pathogen in the wild may be due to the effects of additional environmental factors that impair this innate defense mechanism, leading to the observed population declines...

..The B1-selective analogue [Arg0,Trp5,Leu8,des-Arg9]-BK was inactive at nanomolar concentrations. Taken together, these results strongly support the gene's identity as a piscine orthologue of the mammalian B2 receptor...

..The data indicate that the metabolic actions of an endogenous elasmobranch insulin in an elasmobranch are similar to those previously described for mammalian insulin...

..This may provide some natural resistance to infection, but if environmental factors inhibit the synthesis and release of the skin peptides, the pathogen could gain the advantage...

..coli were japonicin-1, 30 microM; japonicin-2, 12 microM; and temporin-1Ja > 100 microM. The MICs against S. aureus were japonicin-1, > 100 microM; japonicin-2, 20 microM; and temporin-1Ja, > 100 microM...

..The hemolytic activity of fallaxin was very low (HC50>200 microM). A second peptide, comprising residues (1-22) of fallaxin, was also isolated from the skin secretions but this component was inactive against the microorganisms tested...

..septentrionalis and the frogs of the R. pipiens and R. boylii groups...

..These results increase our understanding of the evolution of BK receptors and the functions of the kallikrein-kinin system...

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..In R. tagoi, preproMRP mRNA was not detected in skin prior to the onset of metamorphosis, but its level increased markedly during metamorphosis reaching a maximum at the stages of metamorphic climax...

..It is speculated that the coevolution of a novel pheromone and its complementary receptor in the Nara newts may lead to reproductive isolation and eventual differentiation into a separate species...

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..sakuraii dermal peptides with those of Tago's brown frog Rana tagoi provides evidence for a close phylogenetic relationship between these species...

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..5 microM) and producing hemolysis of human erythrocytes (LD50 = 50 microM)...

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..dendrobatidis in nature. Possible differences in the antimicrobial peptide repertoires and life history traits of the two species that may account for differences in susceptibility are discussed...

..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...

..It is suggested that this peptide may play an important role in initiating the competitive male-male interactions that are associated with the onset of reproductive behavior in L. fallax...

..conserved in mammals, with the exception of the rodents, the extreme variability in the sequences of amphibian and reptilian PPs means that the peptide is a useful molecular marker to study the branching order in early tetrapod evolution..