October 2015 Could a lectin engineered from bananas fight many deadly viruses? New results show promise

An international team of scientists including researchers from NUI Galway have found that the substance BanLec, originally found in bananas, through careful modification could fight off a wide range of viruses in the near future. The results from the study were recently published in the international journal Cell.

The research focuses on a particular carbohydrate binding protein called banana lectin, or BanLec, that “reads” the sugars on the outside of both viruses and cells by sticking to cell structures, or glycans, containing the simple sugar mannose. When BanLec is modified slightly by scientists, it shows promise as an anti-viral drug. While the natural BanLec fights viruses it also causes inflammation. However the newly engineered BanLec can fight viruses without causing inflammation.

A number of Chemistry groups, those of Professor Paul Murphy at the School of Chemistry in NUI Galway, Professor Stefan Oscarson at University College Dublin and Professor René Roy at Université du Québec à Montréal, designed and synthesised mimics of glycans called glycoclusters, which were evaluated by other team members as blockers of both the natural and the newly engineered BanLec.

Professor Paul Murphy of NUI Galway said: “The research shows the contribution that chemists make in the design and synthesis of blockers of lectins. The materials prepared helped provide insight into the mechanism of action of the BanLecs, which was part of the wider study.”

The natural version of BanLec has one less tiny spot on its surface for sugars to attach. This made it impossible for sugars on the surface of immune system cells called T cells, to attach and trigger inflammation. While the new version of BanLec can still grab on to sugars on the surface of viruses and block them from getting into cells.

Professor David Markovitz, co-senior author of the new paper, and Professor of Internal Medicine at the University of Michigan Medical School said: “What we’ve done is exciting because there is potential for BanLec to develop into a broad spectrum antiviral agent, something that is not clinically available to physicians and patients right now.’’

Professor Hans-Joachim Gabius, of the Ludwig Maximilian University of Munich, an acknowledged expert on lectins and their interactions with sugars (the sugar code), and a major contributor to this research said: “One major advantage of designer lectins lies in the fact that the risk of resistance is lower, because glycans that interact with the BanLecs cannot be altered easily.”

The 26 international scientists involved in the study were from Ireland, Germany, Canada, Belgium and the United States.

The research was funded by the US and European governments, and by foundations, including Science Foundation Ireland.

To view the paper in Cell visit: http://dx.doi.org/10.1016/j.cell.2015.09.056 

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