Scots researchers have discovered a way to tag proteins in the body with sugar molecules linked to Alzheimer’s and Parkinson’s.

There are over 20,000 proteins in every human cell and around one in five contains a small sugar molecule called O-GlcNAc. 

Its exact role remains a mystery but the molecule is found on proteins related to Alzheimer’s, Parkinson’s, motor neurone disease and intellectual disability.

This has led scientists to hypothesise that O-GlcNAc disruption is linked to these diseases. 

Increasing the levels of the sugar appears to be of therapeutic benefit. 

Professor Daan van Aalten and his team at Dundee University’s School of Life Sciences have now developed a technique that enables them to permanently fix the sugar on to proteins where it naturally occurs at only low levels.

This will allow them to explore exactly what the sugar molecule does.

The researchers believe their method, combined with rapidly developing gene editing technology, could help understand the causes of diseases such as Alzheimer’s where this sugar modification is disrupted. 

The findings are published today in the journal Nature Structural and Molecular Biology.

Mr van Aalten said: “It is likely that perturbation of the O-GlcNAc sugar on just a single protein could have deleterious effects on healthy neurons and other cells but until recently, the research field lacked methods to investigate this. We have now created the tool that enables us to do this. This allows us to ask questions about the role of sugar modifications in cases of intellectual disability, as well as other brain diseases.”