Acanthoscurrin: a novel glycine-rich antimicrobial peptide constitutively expressed in the hemocytes of the spider Acanthoscurria gomesiana.
ABSTRACT We report the isolation of a novel antimicrobial peptide, acanthoscurrin, from the hemocytes of unchallenged tarantula spider Acanthoscurria gomesiana. A combination of Edman degradation, mass spectrometry and cDNA cloning revealed the presence of two isoforms of acanthoscurrin, differing by two glycine residues. Both displayed cationic properties and a high percentage of glycine residues. However, acanthoscurrins have no structural similarities with already known glycine-rich antimicrobial peptides from animals and plants. As deduced from cDNA cloning and mass spectrometry, the amino acid sequence of acanthoscurrin begins with a putative signal peptide of 23 amino acids followed by the mature peptide, which is post-translationally modified by a C-terminal amidation. Acanthoscurrins are constitutively expressed in hemocytes and released to plasma following an immune challenge.
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ABSTRACT: Defensins are a major family of antimicrobial peptides found throughout the phylogenetic tree. From the spider species: Cupiennius salei, Phoneutria reidyi, Polybetes pythagoricus, Tegenaria atrica, and Meta menardi, defensins belonging to the 'ancestral' class of invertebrate defensins were cloned and sequenced. The deduced amino acid sequences contain the characteristic six cysteines of this class of defensins and reveal precursors of 60 or 61 amino acid residues. The mature peptides consist of 37 amino acid residues, showing up to 70% identities with tick and scorpion defensins. In C. salei, defensin mRNA was found to be constitutively expressed in hemocytes, ovaries, subesophageal nerve mass, hepatopancreas, and muscle tissue. This is the first report presenting and comparing antimicrobial peptides belonging to the family of defensins from spiders.Cellular and Molecular Life Sciences CMLS 04/2010; 67(15):2643-51. · 6.57 Impact Factor
Article: Purification and structural characterization of a novel antibacterial peptide from Bellamya bengalensis: activity against ampicillin and chloramphenicol resistant Staphylococcus epidermidis.[show abstract] [hide abstract]
ABSTRACT: Increasing tendency of clinical bacterial strains resistant to conventional antibiotics has being a great challenge to the public's health. Antimicrobial peptides, a new class of antibiotics is known to have the activity against a wide range of bacteria resistant to conventional antibiotics. An antimicrobial peptide of 1676 Da was purified from Bellamya bengalensis, a fresh water snail, using ultrafiltration and reversed phase liquid chromatography. The effect of this peptide on Staphylococcus epidermidis resistant to ampicillin and chloramphenicol was investigated; the MIC and MBC values were 8 μg/ml and 16 μg/ml, respectively. Complete sequence of the peptide was determined by tandem mass spectrometry (MS/MS). Further, peptide net charge, hydrophobicity and molecular modeling were evaluated in silico for better understanding the probable mechanisms of action. The peptide showed the specificity to bacterial membranes. Hence, this reported peptide revealed a promising candidate to contribute in the development of therapeutic agent for Staphylococcal infections.Peptides 01/2011; 32(4):691-6. · 2.43 Impact Factor
Article: Purification andstructuralcharacterizationofanovelantibacterialpeptidefrom Bellamya bengalensis: Activityagainstampicillinandchloramphenicolresistant Staphylococcus epidermidisPeptides. 01/2011;