Science - February 11, 2010

Flavoenzyme paves the way for nerves

The flavoenzyme Mical plays a key role in the formation of the neural network in our brains. So says Wageningen biochemist Willem van Berkel in an article in Nature published with colleagues at the University of Texas this week.

Van Berkel is an expert on the flavoenzymes. It was already known that this group of enzymes was involved in detoxifying toxic compounds and producing hormones and antibiotics. But flavoenzymes also play an important role in our brains, it now appears from Van Berkel's research with American neuroscientists.
Mical seems to play a key role in enabling the growing terminals of nerve cells to feel their way through the body. These axons, which can be up to a metre in length, can branch out and reach many parts of the brain to transmit impulses to other cells. A growing axon explores its surroundings with its terminal to identify proteins which either attract or reject the nerve fibre. That's how it finds its way. Mical's role in this is crucial, as the enzyme paves the way for the axon by locally dissolving the cell walls of body cells. It does this with a kind of 'active bleach'.
Mical is found not only in nerve cells but also in lung, spleen and testicle cells in young and adult animals. The enzyme operates continuously in a chain with other proteins, thereby receiving signals from proteins outside the cell and steering proteins in the cell. This causes the outside of body cells to change form continuously, says Van Berkel.
Van Berkel's publication in Nature came about through his meeting with an American research project leader at a conference in Europe. The American researcher wanted to know more about Mical. This led to the unusual collaboration between biochemistry and neuroscience. Besides their uses in fine chemicals and foodstuffs, flavoenzymes could also be interesting 'building blocks' for medicines. Together with the American group, Van Berkel is now going to investigate the role of the cooperating proteins around Mical in the formation of organs and in the biology of cancer.
Another colleague of Van Berkel's has a publication in Nature to look forward to. Next month's issue will include an article by biochemist Dolf Weijers on the development of stem cells in plants. It is rare for a Wageningen chair group to get two articles published in close succession in such a prestigious journal.