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Wang,W; Liu,Z; Qian,W; Fang,Y; Liang,S. |
Peptide toxins are usually highly bridged proteins with multipairs of intrachain disulfide bonds. Analysis of disulfide connectivity is an important facet of protein structure determination. In this paper, we successfully assigned the disulfide linkage of two novel peptide toxins, called HNTX-III and HNTX-IV, isolated from the venom of Ornithoctonus hainana spider. Both peptides are useful inhibitors of TTX-sensitive voltage-gated sodium channels and are composed of six cysteine residues that form three disulfide bonds, respectively. Firstly, the peptides were partially reduced by tris(2-carboxyethyl)-phosphine (TCEP) in 0.1 M citrate buffer containing 6 M guanidine-HCl at 40° C for ten minutes. Subsequently, the partially reduced intermediates containing... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Disulfide bonds; TCEP; Partial reduction; HNTX-III; HNTX-IV. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992009000200009 |
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Fang,Longfa; Wang,Bo; Zhou,Zishan; Yang,Sujuan; Shu,Changlong; Song,Fuping; Bravo,Alejandra; Soberón,Mario; Zhang,Jie. |
Background: Bacillus thuringiensis Cry toxins bind with different insect midgut proteins leading to toxin oligomerization, membrane insertion and pore formation. However, different Cry toxins had been shown to readily form high molecular weight oligomers or aggregates in solution in the absence of receptor interaction. The role of Cry oligomers formed in solution remains uncertain. The Cry9A proteins show high toxicity against different Lepidoptera, and no-cross resistance with Cry1A. Results: Cry9Aa655 protein formed oligomers easily in solution mediated by disulfide bonds, according to SDS-PAGE analysis under non-reducing and reducing conditions. However, oligomerization is not observed if Cry9Aa655 is activated with trypsin, suggesting that cysteine... |
Tipo: Journal article |
Palavras-chave: Cry9Aa655; Disulfide bonds; Oligomerization; Insecticidal activity. |
Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000300006 |
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