New tricks of an old pattern: structural versatility of scorpion toxins with common cysteine spacing
| Autor: | Alma Leticia, Saucedo, David, Flores-Solis, Ricardo C, Rodríguez de la Vega, Belén, Ramírez-Cordero, Rogelio, Hernández-López, Patricia, Cano-Sánchez, Roxana, Noriega Navarro, Jesús, García-Valdés, Fredy, Coronas-Valderrama, Adolfo, de Roodt, Luis G, Brieba, Lourival, Domingos Possani, Federico, del Río-Portilla |
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| Rok vydání: | 2012 |
| Předmět: |
Chromatography
Reverse-Phase animal structures Surface Properties Recombinant Fusion Proteins Xenopus Amino Acid Motifs Molecular Sequence Data Scorpion Venoms complex mixtures Membrane Potentials Protein Structure Tertiary Scorpions Sequence Analysis Protein Structural Homology Protein Protein Structure and Folding Animals Amino Acid Sequence Cysteine Nuclear Magnetic Resonance Biomolecular Chromatography High Pressure Liquid |
| Zdroj: | The Journal of biological chemistry. 287(15) |
| ISSN: | 1083-351X |
| Popis: | Scorpion venoms are a rich source of K(+) channel-blocking peptides. For the most part, they are structurally related small disulfide-rich proteins containing a conserved pattern of six cysteines that is assumed to dictate their common three-dimensional folding. In the conventional pattern, two disulfide bridges connect an α-helical segment to the C-terminal strand of a double- or triple-stranded β-sheet, conforming a cystine-stabilized α/β scaffold (CSα/β). Here we show that two K(+) channel-blocking peptides from Tityus scorpions conserve the cysteine spacing of common scorpion venom peptides but display an unconventional disulfide pattern, accompanied by a complete rearrangement of the secondary structure topology into a CS helix-loop-helix fold. Sequence and structural comparisons of the peptides adopting this novel fold suggest that it would be a new elaboration of the widespread CSα/β scaffold, thus revealing an unexpected structural versatility of these small disulfide-rich proteins. Acknowledgment of such versatility is important to understand how venom structural complexity emerged on a limited number of molecular scaffolds. |
| Databáze: | OpenAIRE |
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