A fast multi-step microreactor for enzymatic synthesis has been developed by scientists in Germany.

The system has influences from both chemical synthesis and molecule biology according to its developers, Gerald Dräger and colleagues from University of Hannover in Leibniz. The new system enables both the immobilisation and purification of enzymes in the same reactor, which can then be used for a variety of enzymatic syntheses. Using this technique it is possible to obtain ready-to-use enzyme reactors from crude protein mixtures within minutes.

The system uses immobilised Ni-NTA (nitrilotriacetic acid) with a new tyrosine linker, attached to polymeric materials inside the reactor chamber. The reactor itself is integrated into an HPLC set-up. The NTA component is used in metal ion affinity chromatography, which in turn can be used to purify His6-tagged proteins from crude cell extracts. The polymeric materials in the reactor have also been altered to be more polar, ideal for biological molecules.

'The NTA linker is used to chelate with the Ni ion. The bound Ni ions themselves catch enzymes or proteins in the solution,' explained Dräger. This means that crude cell extracts can be both purified and immobilised simultaneously using this system, speeding up the whole process as normal reactors miss the purification step.

'The new tyrosine-based linker as compared to the standard lysine linker gives us higher loadings, increased efficiency and less purity problems,' added Dräger. The reactor system is flexible meaning that different enzymes can be used. It also has the added advantages that it is licence-free and the reactor can be re-used a number of times.

Michele Zgraggen