BmNPV Protein Expression Approaches

Silkworm has a long history of being used as bioreactor for it can massively produce recombinant proteins at a low cost. Theoretically, the process of using silkworm to express recombinant protein is simpler than AcMNPV. As long as the recombinant virus is injected into the larva, the target protein can be obtained from silkworm hemolymph. However, it is difficult to generate recombine baculovirus by co-transfection. On top of that, it is also difficult to get high titer BmNPV. It usually takes 3-6 months before the virus titer is high enough to be injected into the silkworm.

Evolution of BmNPV Expression System

To address the problem of recombinant virus generation and amplification problem, a BmNPV Bac-to-Bac system is constructed according to the principle of AcMNPV Bac-to-Bac system. 

The manipulated BmNPV was named as BmBacmid. Same as AcMNPV bacmid, it has a large fragment that contains mini-F replicon, Kanamycin resistance marker, lacZαpeptide segment and a bacterial transposon targeting sit (mini-attTn7). The manipulated BmNPV was named as BmBacmid. Later the BmBacmid was transferred into the E. coli DH10 which contains a helper plasmid (Figure 1).

This BmBacmid system has the same working mechanism with AcMNPV while it shows a greater capacity of rapid recombinant protein expression. The recombinant baculovirus can be generated easily through homologous recombination at mini-attTn7 sit. In addition, BmNPV Bac-to-Bac system requires neither virus amplification, nor preparation of recombinant bacmid solution for transfection. Thus, BmBacmid system dramatically reduced the expression period.

With the development of BmNPV system, more approaches have been developed. Some methods can achieve small-scale but rapid protein expression through dorsal injection while others let larva express large-scale recombinant protein by oral infection.

What we have for you

Creative BioMart offers two kinds of BmBacmid and corresponding expression services to meet different requirements. Click the links below to learn more information or contact us to decide a suitable approach for your protein. If you had already made your own expression plan which is beyond our list, our edge-cutting technology platform is still able to provide assistance for you. All you need to do is to contact us and put forward your requirements.

• Polh-negative BmBacmid

Polyhedrin locus was knocked out, highly infectious for hemocoel tissues and cultured cells, requires neither transfection nor amplification. Suitable for small-scale fast protein production.

• Polh-positive BmBacmid

Polyhedrin remained. Highly infectious to the midgut epithelial cells and mediate infectious to larva transmission. Requires transfection but not amplification. Suitable for large-scale protein production.