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Citation |
Kauferstein S, Porth C, Kendel Y, Wunder C, Nicke A, Kordis D, Favreau P, Koua D, Stöcklin R, Mebs D. Toxicon 2011; 57(1): 28-34. |
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Affiliation |
Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, D-60596 Frankfurt, Germany. |
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Copyright |
(Copyright © 2011, Elsevier Publishing) |
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DOI |
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PMID |
20933537 |
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Abstract |
From six Conus species (C. coronatus, C. lividus, C. mozambicus f. lautus, C. pictus, C. sazanka, C. tinianus) collected off the eastern coast of South-Africa the venoms were analyzed using MALDI-TOF mass spectrometry. Between 56 to 151 molecular masses most in a range of 1,000 to 2,500 Da, were identified. Among the six venoms, between 0 to 27% (C. coronatus versus C. sazanka) of the peptide masses were found to be similar. In a study on venoms from 6 Conus species collected in the Philippines, the percentage of identical masses was between none to 9% only. The venoms from the South-African Conus species antagonized the rat neuronal nicotinic acetylcholine receptors (nAChRs) α3β2, α4β2, and α7, except for C. coronatus venom which blocked the α4β2 and α7 nAChRs only. HPLC-fractionation of C. tinianus venom led to the isolation of a peptide that is active on all three receptor subtypes. It consists of 16 amino acid residues cross-linked by two disulfide bridges as revealed by de novo sequencing using tandem mass spectrometry: GGCCSHPACQNNPDYC. Posttranslational modifications include C-terminal amidation and tyrosine sulfation. The new peptide is a member of the α-conotoxin family which are competitive antagonists of nAChRs. Phylogenetic analysis of the 16S RNA from numerous Conus species has clarified the evolutionary position of endemic South African Conus species and provided the first evidence for their close genetic relationships. Language: en |