Linked Life Data

12692120

Source:http://linkedlifedata.com/resource/pubmed/id/12692120

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2003-6-23
pubmed:abstractText
About one-third of the amino acid residues conserved in all scorpion long chain Na+ channel toxins are aromatic residues, some of which constitute the so-called "conserved hydrophobic surface." At present, in-depth structure-function studies of these aromatic residues using site-directed mutagenesis are still rare. In this study, an effective yeast expression system was used to study the role of seven conserved aromatic residues (Tyr5, Tyr14, Tyr21, Tyr35, Trp38, Tyr42, and Trp47) from the scorpion toxin BmK M1. Using site-directed mutagenesis, all of these aromatic residues were individually substituted with Gly in association with a more conservative substitution of Phe for Tyr5, Tyr14, Tyr35, or Trp47. The mutants, which were expressed in Saccharomyces cerevisiae S-78 cells, were then subjected to a bioassay in mice, electrophysiological characterization on cloned Na+ channels (Nav1.5), and CD analysis. Our results show an eye-catching correlation between the LD50 values in mice and the EC50 values on Nav1.5 channels in oocytes, indicating large mutant-dependent differences that emphasize important specific roles for the conserved aromatic residues in BmK M1. The aromatic side chains of the Tyr5, Tyr35, and Trp47 cluster protruding from the three-stranded beta-sheet seem to be essential for the structure and function of the toxin. Trp38 and Tyr42 (located in the beta2-sheet and in the loop between the beta2- and beta3-sheets, respectively) are most likely involved in the pharmacological function of the toxin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24125-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Importance of the conserved aromatic residues in the scorpion alpha-like toxin BmK M1: the hydrophobic surface region revisited.
pubmed:affiliation
Center for Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People's Republic of China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't