Characterization of Novel Cysteine-rich Antimicrobial Peptides from Scorpion Blood

Abstract

We have isolated, from the hemolymph of unchallenged scorpions of the species Androctonus australis, three distinct antimicrobial peptides, which we have fully characterized by Edman degradation, electrospray ionization mass spectrometry, and matrix-assisted laser desorption/ionization mass spectrometry. Two are novel molecules: (i) androctonin, a 25-residue peptide with two disulfide bridges, active against both bacteria (Gram-positive and Gram-negative) and fungi and showing marked sequence homology to tachyplesins and polyphemusins from horseshoe crabs; and (ii) buthinin, a 34-residue antibacterial (Gram-positive and Gramnegative) peptide with three disulfide bridges. The third peptide contains 37 residues and three disulfide bridges and clearly belongs to the family of anti-Gram-positive insect defensins. We have synthesized androctonin and explored its activity spectrum and mode of action.

Discovery and Characterization of Two Isoforms of Moronecidin, a Novel Antimicrobial Peptide from Hybrid Striped Bass

“…Structure Determination and Microsequence Analysis-The purity of the peptides was confirmed by capillary zone electrophoresis (model 270A-HT Capillary Electrophoresis System; PerkinElmer Applied Biosystems) equipped with a fused silica tube (length, 72 cm; internal diameter, 50 m) as described previously (24).…”

Unique diversity of the venom peptides from the scorpion Androctonus bicolor revealed by transcriptomic and proteomic analysis

“…They function as host defense peptides. Until now, at least eleven defensins have been identified from the venom of scorpions, including TXKs2, defensin-1, -2, -3, -4, -5 and -6 from M. martensii Karsch [19], P56686 from A. australis and P41965 from Leiurus quinquestriatus hebraeus [60,61], Q6GU94 from Centruroides limpidus limpidus and Td defensin from Tityus discrepans. Here, we found that the transcripts of 4 unique novel defensins, which were referred to as AbDef-1 (KJ787323), AbDef-3 (KJ787318), AbDef-4 (KJ787319) and AbDef-5 (KJ787316), respectively, are present in the venom transcriptome of the scorpion A. bicolor.…”

Penaeidins, a New Family of Antimicrobial Peptides Isolated from the Shrimp Penaeus vannamei (Decapoda)

“…For the time being and for convenience, these antimicrobial peptides are tentatively classified into four distinct groups based on amino acid sequences, secondary structures, and functional similarities: (i) linear basic peptides forming amphipathic ␣-helices including the cecropins, the first antimicrobial peptide isolated from insect hemolymph (for review see Ref. 9); (ii) peptides with one to six intramolecular disulfide bridges including the arthropod defensins (10), antifungal peptides from Drosophila, drosomycin (11) and metchnikowin (12), thanatin from Podisus (13), tachyplesin, big defensin and tachycitin from limulus (14 -16), and other cysteine-rich antimicrobial peptides isolated from a scorpion (17) and from a bivalve mollusk (18,19); (iii) prolinerich peptides, among them the apidaecins and abaecins from Hymenoptera (20,21) and drosocin from Drosophila hemolymph (22); (iv) glycine-rich antimicrobial peptides or polypeptides (9 -30 kDa) such as the attacins (23), diptericin (24) and sarcotoxins (25). The mode of action, the broad activity, the molecular diversity, and the noncytotoxicity of all these circulating antimicrobial peptides make them very attractive as therapeutic agents for pharmaceutical or agricultural applications (26,27).…”