Affiliations: Department of Physics, Indian Institute of Science,
Bangalore 560 012, India | Department of Botany, Bharathiar University,
Coimbatore, India | Bioinformatics Centre, Indian Institute of Science,
Bangalore 560 012, India
Abstract: I-superfamily conotoxins have four-disulfide bonds with cysteine
arrangement C-C-CC-CC-C-C, and they inhibit or modify ion channels of nerve
cells. They have been characterized only recently and are relatively less well
studied compared to other superfamily conotoxins. We have detected selective
and sensitive sequence pattern for I-superfamily conotoxins. The availability
of sequence pattern should be useful in protein family classification and
functional annotation. We have built by homology modeling, a theoretical
structural 3D model of ViTx from Conus virgo, a typical member of I-superfamily
conotoxins. The modeling was based on the available 3D structure of
Janus-atracotoxin-Hv1c of Janus-atracotoxin family whose members have been
suggested as possible biopesticides. A study comparing the theoretically
modeled structure of ViTx, with experimentally determined structures of other
toxins, which share functional similarity with ViTx, reveals the crucial role
of C-terminal region of ViTx in blocking therapeutically important
voltage-gated potassium channels.
