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Frank F Bier – One of the best experts on this subject based on the ideXlab platform.

  • peptide microarrays with site specifically immobilized synthetic Peptides for antibody diagnostics
    Sensors and Actuators B-chemical, 2006
    Co-Authors: Heiko Andresen, Frank F Bier, Carsten Grotzinger, Kim Zarse, Marc Birringer, Carsten Hessenius, Oliver J Kreuzer, Eva Ehrentreichforster
    Abstract:

    Peptide microarrays bear the potential to discover molecular recognition events on protein level, particularly in the field of molecular immunology, in a manner and with an efficiency comparable to the performance of DNA microarrays. We developed a novel peptide microarray platform for the detection of antibodies in liquid samples. The system comprises site-specific solution phase coupling of biotinylated Peptides to NeutrAvidin, localized microdispensing of peptide-NeutrAvidin conjugates onto activated glass slides and a fluorescence immuno sandwich assay format for antibody capture and detection. Our work includes synthetic Peptides deduced from amino acid sequences of immunodominant linear epitopes, such as the T7 phage capsid protprotein, Herpes simplex virus glycoprotein D, c-myc protein and three domains of the Human coronavirus 229E polymerase polyprotein. We demonstrate that our method produces peptide arrays with excellent spot morphology which are capable of specific and sensitive detection of monoclonal antibodies from fluid samples.

Anatoli Ianoul – One of the best experts on this subject based on the ideXlab platform.

  • Investigating the effect of a single glycine to alanine substitution on interactions of antimicrobial peptide latarcin 2a with a lipid membrane
    European Biophysics Journal, 2011
    Co-Authors: Grace Idiong, Annamaria Ruscito, Bonnie O. Leung, Adam P. Hitchcock, Anatoli Ianoul
    Abstract:

    Latarcins are linear, α-helical antimicrobial Peptides purified from the venom of the Central Asian spider Lachesana tarabaevi , with lytic activity against Gram-positive and Gram-negative bacteria, erythrocytes, and yeast at micromolar concentrations. In this work, we investigated the role of the hinge in latarcin 2a (ltc2a, GLFGKLIKKF G RKAISYAVKKARGKH-COOH), which adopts a helix–hinge–helix conformation in membrane-mimicking environments, on peptide–membrane interactions and its potential effect on the selective toxicity of the peptide. A modified latarcin 2a, ltc2aG11A, obtained by replacing the glycine at position 11 with alanine (ltc2aG11A, GLFGKLIKKF A RKAISYAVKKARGKH-COOH), adopts a more rigid structure due to the reduced conformational flexibility. Langmuir monolayer measurements combined with atomic force microscopy and X-ray photoemission electron microscopy (X-PEEM) indicate that both Peptides bind and insert preferentially into anionic compared with zwitterionic phospholipid monolayers. Modified ltc2aG11A was found to be more disruptive of supported phospholipid bilayer modeling mammalian cell membrane. However, no considerable difference in lytic activity of the two Peptides toward bacterial membrane was found. Overall the data indicate that decrease in the flexibility of ltc2a induced by the modification in the hinge region is likely to increase the peptide’s nonspecific interactions with zwitterionic cell membranes and potentially increase its toxicity against eukaryotic cells.

  • Investigating the effect of a single glycine to alanine substitution on interactions of antimicrobial peptide latarcin 2a with a lipid membrane
    European Biophysics Journal, 2011
    Co-Authors: Grace Idiong, Annamaria Ruscito, Bonnie O. Leung, Adam P. Hitchcock, Amy Won, Anatoli Ianoul
    Abstract:

    Latarcins are linear, α-helical antimicrobial Peptides purified from the venom of the Central Asian spider Lachesana tarabaevi , with lytic activity against Gram-positive and Gram-negative bacteria, erythrocytes, and yeast at micromolar concentrations. In this work, we investigated the role of the hinge in latarcin 2a (ltc2a, GLFGKLIKKF G RKAISYAVKKARGKH-COOH), which adopts a helix–hinge–helix conformation in membrane-mimicking environments, on peptide–membrane interactions and its potential effect on the selective toxicity of the peptide. A modified latarcin 2a, ltc2aG11A, obtained by replacing the glycine at position 11 with alanine (ltc2aG11A, GLFGKLIKKF A RKAISYAVKKARGKH-COOH), adopts a more rigid structure due to the reduced conformational flexibility. Langmuir monolayer measurements combined with atomic force microscopy and X-ray photoemission electron microscopy (X-PEEM) indicate that both Peptides bind and insert preferentially into anionic compared with zwitterionic phospholipid monolayers. Modified ltc2aG11A was found to be more disruptive of supported phospholipid bilayer modeling mammalian cell membrane. However, no considerable difference in lytic activity of the two Peptides toward bacterial membrane was found. Overall the data indicate that decrease in the flexibility of ltc2a induced by the modification in the hinge region is likely to increase the peptide’s nonspecific interactions with zwitterionic cell membranes and potentially increase its toxicity against eukaryotic cells.

Kazuyoshi Tsutsui – One of the best experts on this subject based on the ideXlab platform.

  • Evolutionary origin and divergence of PQRFamide Peptides and LPXRFamide Peptides in the RFamide peptide family: Insights from novel lamprey RFamide Peptides
    The FEBS journal, 2006
    Co-Authors: Tomohiro Osugi, Kazuyoshi Ukena, Stacia A. Sower, Hiroshi Kawauchi, Kazuyoshi Tsutsui
    Abstract:

    Among the RFamide peptide groups, PQRFamide Peptides, such as neuropeptide FF (NPFF) and neuropeptide AF (NPAF), share a common C-terminal Pro-Gln-Arg-Phe-NH2 motif. LPXRFamide (X = L or Q) Peptides, such as gonadotropin-inhibitory hormone (GnIH), frog growth hormone-releasing peptide (fGRP), goldfish LPXRFamide peptide and mammalian RFamide-related Peptides (RFRPs), also share a C-terminal Leu-Pro-Leu/Gln-Arg-Phe-NH2 motif. Such a similar C-terminal structure suggests that these two groups may have diverged from a common ancestral gene. In this study, we sought to clarify the evolutionary origin and divergence of these two groups, by identifying novel RFamide Peptides from the brain of sea lamprey, one of only two extant groups of the oldest lineage of vertebrates, Agnatha. A novel lamprey RFamide peptide was identified by immunoaffinity purification using the antiserum against LPXRFamide peptide. The lamprey RFamide peptide did not contain a C-terminal LPXRFamide motif, but had the sequence SWGAPAEKFWMRAMPQRFamide (lamprey PQRFa). A cDNA of the precursor encoded one lamprey PQRFa and two related Peptides. These related Peptides, which also had the C-terminal PQRFamide motif, were further identified as mature endogenous ligands. Phylogenetic analysis revealed that lamprey PQRFamide peptide precursor belongs to the PQRFamide peptide group. In situ hybridization demonstrated that lamprey PQRFamide peptide mRNA is expressed in the regions predicted to be involved in neuroendocrine and behavioral functions. This is the first demonstration of the presence of RFamide Peptides in the agnathan brain. Lamprey PQRFamide Peptides are considered to have retained the most ancestral features of PQRFamide Peptides.