Pepping up nervous activity

Researchers at the Universities of Bielefeld and Hamburg in Germany have found a group of cyclic peptides that imitate the HNK-1 carbohydrate from human natural killer cells. This carbohydrate is involved in many developmental biological processes of the nervous system, such as boosting motor neuron axon growth. It also promotes the growth of the fibers of muscle nerve cells. As such, medical scientists hope it will play a role in the repair of damaged peripheral nerves. Norbert Sewald (Bielefeld) and Melitta Schachner (Hamburg) scanned a linear peptide library HNK-1 antibody recognition. They then used the two most successful peptides as the prototypes for making a series of cyclic analogs. They tested the new compounds against motor neuron cell cultures and found that two of the cyclic peptides stimulated axon growth. In fact, these synthetic compounds were more effective than the natural substrate. The researchers suggest the further development of these compounds is a step towards a drug-based treatment for spinal injury.