Linked Life Data

2295621

Source:http://linkedlifedata.com/resource/pubmed/id/2295621

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-2-21
pubmed:abstractText
A new series of polypeptide presynaptic antagonists ("omega-agatoxins") was purified from venom of the funnel web spider Agelenopsis aperta. Physiological data indicate that all of these peptides are antagonists of voltage-sensitive calcium channels. Although all three omega-agatoxins (Aga) described here (omega-Aga-IA, omega-Aga-IB, and omega-Aga-IIA) block insect neuromuscular transmission presynaptically, biochemical data permit their subclassification as Type I and Type II toxins. Type I toxins (omega-Aga-IA and -IB) are 7.5 kDa, have closely related amino acid sequences, and exhibit characteristic tryptophan-like UV absorbance spectra. Complete Edman sequencing of omega-Aga-IA reveals it to be a 66-amino acid polypeptide containing 9 cysteines and 5 tryptophan residues. omega-Aga-IIA, a Type II toxin, is 11 kDa, shows limited amino acid sequence similarity to the Type I toxins, and exhibits mixed tryptophan- and tyrosine-like absorbance. Nanomolar concentrations of omega-Aga-IIA inhibit the specific binding of 125I-labeled omega-conotoxin GVIA to chick synaptosomal membranes while omega-Aga-IA and -IB have no effect under identical conditions. The omega-agatoxins thus are defined as two subtypes of neuronal calcium channel toxins with different structural characteristics and calcium channel binding specificities.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
861-7
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Omega-agatoxins: novel calcium channel antagonists of two subtypes from funnel web spider (Agelenopsis aperta) venom.
pubmed:affiliation
Department of Entomology, University of California, Riverside 92521.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.