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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-1-31
pubmed:abstractText
Martentoxin, a novel K+-channel-specific peptide has been purified and characterized from the venom of the East-Asian scorpion (Buthus martensi Karsch). The whole cDNA precursor sequence suggested that martentoxin was composed of 37 residues with a unique sequence compared with other scorpion neurotoxins. The genomic DNA of martentoxin showed an additional intron situated unexpectedly in the 5' UTR region, besides one located close to the C-terminal of the signal peptide. The patch-clamp recording found that martentoxin at the applied dose of 100 nm could strongly block large-conductance Ca2+-activated K+ (BKCa) currents in adrenal medulla chromaffin cells, and BKCa currents blocked by martentoxin could be fully recovered within 30 seconds after washing, which is at least 10 times faster than recovery after charybdotoxin. Meanwhile, a biosensor binding assay showed a fast association rate and a slow dissociation rate of martentoxin binding on rat brain synaptosomes. The binding of martentoxin on rat brain synaptosomes could be inhibited regularly by charybdotoxin, and gradually by toosendanin in a concentration-dependent manner, but not by either apamin or P03 from Buthus martensi. The results thus indicate that martentoxin is a new member in the family of K+-channel-blocking ligands.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
325-35
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12558995-Amino Acid Sequence, pubmed-meshheading:12558995-Animals, pubmed-meshheading:12558995-Base Sequence, pubmed-meshheading:12558995-Binding, Competitive, pubmed-meshheading:12558995-Chromaffin Cells, pubmed-meshheading:12558995-DNA, Complementary, pubmed-meshheading:12558995-Dose-Response Relationship, Drug, pubmed-meshheading:12558995-Electrophysiology, pubmed-meshheading:12558995-Genomic Library, pubmed-meshheading:12558995-Molecular Sequence Data, pubmed-meshheading:12558995-Patch-Clamp Techniques, pubmed-meshheading:12558995-Peptides, pubmed-meshheading:12558995-Phylogeny, pubmed-meshheading:12558995-Potassium Channel Blockers, pubmed-meshheading:12558995-Potassium Channels, Calcium-Activated, pubmed-meshheading:12558995-Rats, pubmed-meshheading:12558995-Scorpion Venoms, pubmed-meshheading:12558995-Synaptosomes
pubmed:year
2003
pubmed:articleTitle
Martentoxin, a novel K+-channel-blocking peptide: purification, cDNA and genomic cloning, and electrophysiological and pharmacological characterization.
pubmed:affiliation
Institute of Physiology and Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China. yhji@server.shcnc.ac.cn
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't