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Technology Development
The various technologies being developed or further developed by BayGenetics derive from research and development carried out by Professor Schumann.
The technologies for the anchoring of proteins on cell walls and spores are relevant for enzyme catalysis, molecular diagnostics and the development of vaccines; and the expression system technology for enzyme catalysis and protein synthesis.
Anchoring of proteins on cell walls and spore surfaces
The covalent anchoring of recombinant proteins on cell walls, also known as surface display, allows first the synthesis of almost any protein in the cell, then, via the sec pathway, to export it through the membrane and then anchor it on the cell wall.
An experimental system has already been developed, which allows the covalent anchoring of up to 240,000 protein molecules on a cell wall. Besides the anchoring on the walls of vegetative cells, anchoring can also take place on spore surfaces. Five different proteins are available as anchors to which recombinant proteins can be fused.The anchoring of 5,000 to 10,000 molecules per spore has been reported, but it should be possible to increase this number by using stronger promoters for expression of the fusion proteins.
Expression system
B. subtilis is an ideal host organism for the production of recombinant proteins in four different compartments:
1. intracellular
2. extracellular (secretion)
3. anchoring of proteins on cell walls
4. anchoring of protein on spore surfaces
A strong inducible expression system has already been developed where the amount of intracellular recombinant protein represents up to 43% of the total protein. This system is to be further developed to a secretion system.
Molecular diagnostics
The principle of this method is based on a protein with a sensor domain and a DNA binding domain. This protein is anchored in the cytoplasm membrane, the sensor domain lies extracellular and the DNA binding domain intracellular. If the detected virus (e.g. HIV) is bound on the sensor domain, then two protein molecules dimerise, the DNA binding domain becomes active and binds to a certain DNA sequence, which is part of a plasmid. Through this binding, a RNA polymerase is recruited that transcribes a reporter gene, whose product produces a visible signal in the cell.
Vaccine development
With the mouse model organism it has already been shown that spores are absorbed in the intestine and an immune response is triggered. However, the immune response is not yet satisfactory and has to be strengthened with two flanking measures. A challenge is the absorption of the spores in the intestine through the M cells.
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