Revision as of 17:25, 17 October 2016

T7Promoter+RBS+Hv1a+linker+snowdrop-lectin+linker+6X His-Tag

Introduction:

[[File:|NCTU_H.png|800px|thumb|center|Figure 1.’’’T7promoter+RBS+Hv1a+linker+snoedrop-lectin+linker+6xhistag ]]

       By ligating the IPTG induced promoter T7 (BBa_ I712074), strong ribosome binding site (BBa_B0034), hv1a, linker, and the 6xHistag (BBa_ K1223006), we can express Hv1a, the toxin by IPTG induction
       This year we create a revolutionary system that integrates biological pesticides, automatic detector, sprinkler, and IoT. We made a database that contains most of the spider toxins and selected the target toxins by programming. Omega-hexatoxin-Hv1a is coded for the venom of a spider, Hadronyche versuta.

       It is under the control of the strong T7 promoter. Snowdrop-lectin acts as a carrier that could transport the toxin to insect’s nervous system, hemolymph and can improve the oral activity. A 6xHistag is added for further protein purification.

Mechanism of Hv1a:

       According to reference, snowdrop-lectin is resistant to high temperature and would not be degraded by digestive juice. The species-specificity is based on the toxin, and the snowdrop lectin is the role of the carrier.

       According to reference, Omega-hexatoxin-Hv1a has a structure called ICK(inhibitor cysteine knot).[1](之前PPT裡有) This kind of structure contains three disulfide bonds and beta-sheet. With this structure, Hv1a can resist the high temperature, acid-base solution and the digest juice of insect gut. Hv1a can bind on insect voltage-gated Calcium channels (CaV1) in the central nervous system, making it paralyze and die eventually.

Features of Hv1:

1. Non-toxic: Omega-hexatoxin-Hv1a is non-toxic to mammals and Hymenoptera (bees). Since the structure of the target ion channel is different, omega-hexatoxin-Hv1a does not harm mammals and bees. So it is safe to use it as a biological pesticide.

2. Biodegradable: Omega-hexatoxin-Hv1a is a polypeptide so it must degrade over time. After degradation, the toxin will become nutrition in the soil.

3. Species-specific: According to reference, Omega-hexatoxin-Hv1a has specificity to Lepidopteran (moths), Dipteran (flies) and Orthopteran (grasshoppers).

4. Eco-friendly: Compare with chemical pesticides, Omega-hexatoxin-Hv1a will not remain in soil and water so that it will not pollute the environment and won’t harm the ecosystem.

       Together, using Hv1a is totally an environmentally friendly way for solving harmful insect problems by using this ion channel inhibitor as a biological pesticide.

Sequence and Features