The Cystine Knot Is Responsible for the Exceptional Stability of the Insecticidal Spider Toxin ω-Hexatoxin-Hv1a.

ABSTRACT: The inhibitor cystine knot (ICK) is an unusual three-disulfide architecture in which one of the disulfide bonds bisects a loop formed by the two other disulfide bridges and the intervening sections of the protein backbone. Peptides containing an ICK motif are frequently considered to have high levels of thermal, chemical and enzymatic stability due to cross-bracing provided by the disulfide bonds. Experimental studies supporting this contention are rare, in particular for spider-venom toxins, which represent the largest diversity of ICK peptides. We used ω-hexatoxin-Hv1a (Hv1a), an insecticidal toxin from the deadly Australian funnel-web spider, as a model system to examine the contribution of the cystine knot to the stability of ICK peptides. We show that Hv1a is highly stable when subjec

SUBMITTER: Herzig V 

PROVIDER: S-EPMC4626739 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature