Here we go again, folks. Recently Natural News published an article titled “New, all-natural pesticide unveiled by scientists – and it won’t kill the bees!“
Good news on the honeybee front — a team of scientists in the UK have created a biopesticide made from spider venom and plant protein that may provide hope for the endangered pollinators.Let’s just take a little peek at the source document – “Proceedings of the Royal Society B,” shall we?
A study published in the research journal Proceedings of the Royal Society B [PDF] states that the experimental, nontoxic biopesticide Hv1a/GNA is “unlikely to cause detrimental effects on honeybees.”
Recombinant GNA, and the fusion protein Hv1a/GNA were produced in the yeast expression system…Definition of “recombination:”
Re·com·bi·na·tion noun \ˌrē-ˌkäm-bə-ˈnā-shən\: the formation by the processes of crossing-over and independent assortment of new combinations of genes in progeny that did not occur in the parents.What is a “fusion protein?”
Fusion proteins or chimeric proteins (literally, made of parts from different sources) are proteins created through the joining of two or more genes that originally coded for separate proteins. Translation of this fusion gene results in a single or multiple polypeptides with functional properties derived from each of the original proteins. Recombinant fusion proteins are created artificially by recombinant DNA technology…Sounds like genetic engineering to me. But wait, there’s more…
The making of the Hv1a/GNA pesticide from the Journal of Industrial Microbiology & Biotechnology:
Optimising expression of the recombinant fusion protein biopesticide ω-hexatoxin-Hv1a/GNA in Pichia pastoris: sequence modifications and a simple method for the generation of multi-copy strainsCan we spell GENETIC ENGINEERING, CLONING and MUTAGENESIS?
Production of recombinant protein bio-insecticides on a commercial scale can only be cost effective if host strains with very high expression levels are available. A recombinant fusion protein containing an arthropod toxin, ω-hexatoxin-Hv1a, (from funnel web spider Hadronyche versuta) linked to snowdrop lectin (Galanthus nivalis agglutinin; GNA) is an effective oral insecticide and candidate biopesticide. However, the fusion protein was vulnerable to proteolysis during production in the yeast Pichia pastoris. To prevent proteolysis, the Hv1a/GNA fusion expression construct was modified by site-directed mutagenesis to remove a potential Kex2 cleavage site at the C-terminus of the Hv1a peptide. To obtain a high expressing clone of P. pastoris to produce recombinant Hv1a/GNA, a straightforward method was used to produce multi-copy expression plasmids, which does not require multiple integrations to give clones of P. pastoris containing high copy numbers of the introduced gene. Removal of the Kex2 site resulted in increased levels of intact fusion protein expressed in wild-type P. pastoris strains, improving levels of intact recombinant protein recoverable. Incorporation of a C-terminal (His)6 tag enabled single step purification of the fusion protein. These modifications did not affect the insecticidal activity of the recombinant toxin towards lepidopteran larvae. Introduction of multiple expression cassettes increased the amount of secreted recombinant fusion protein in a laboratory scale fermentation by almost tenfold on a per litre of culture basis. Simple modifications in the expression construct can be advantageous for the generation of high expressing P. pastoris strains for production of a recombinant protein, without altering its functional properties.
So, according to Natural News, genetic engineering, cloning and mutagenesis are “all natural.” So much for labels. Need I say more?
©2014 Barbara H. Peterson