Linked Life Data

7827075

Source:http://linkedlifedata.com/resource/pubmed/id/7827075

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-2-23
pubmed:abstractText
The three-dimensional solution structure of the MTX2 toxin (65 amino acids and 4 disulfides) from the green mamba venom (Dendroaspis angusticeps), a toxin that activates the pharmacological M1 muscarinic acetylcholine receptors, has been determined by nuclear magnetic resonance and molecular modeling. Seventeen structures were calculated from 810 distance and 68 dihedral angle restraints using DIANA and X-PLOR. The average rms deviation between the 17 refined structures and the energy-minimized average structure is 0.95 A for the backbone atoms. The overall folding of MTX2 consists of three loops stabilized by the four disulfides and forming a two- and a three-stranded beta-sheet. This structure appears to be very similar to that of other snake toxins, such as neurotoxins, fasciculins, and cardiotoxins, that also possess the same three-finger fold. For instance, the RMSd for the backbone atoms between MTX2 and the curaremimetic toxin alpha (from Naja nigricollis), the acetylcholinesterase inhibitor fasciculin 1 (from Dendroaspis angusticeps), and the cardiotoxic toxin gamma (from Naja nigricollis) are 1.86, 1.87, and 2.04 A, respectively. Local differences are observed between this toxin and the other structurally related toxins. Some of these differences could be relevant for the functional specificity of MTX2. In particular, this toxin presents a large twist at the tip of loop II due to a bulge (V31, T32; N35) that accommodates an inserted amino acid in the loop. This spatial arrangement brings the side chain of K34 in the beta-turn of the loop to be aligned with the beta-sheet. Hypotheses about a possible functional role of this lysine are described. Other characteristics in the side-chain distribution that could be related to the MTX2 function are presented.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1248-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Solution structure of a green mamba toxin that activates muscarinic acetylcholine receptors, as studied by nuclear magnetic resonance and molecular modeling.
pubmed:affiliation
CEA, Département d'Ingénierie et d'Etude des Protéines, C.E. Saclay, Gif-Sur-Yvette, France.
pubmed:publicationType
Journal Article, Comparative Study