Ian Sims

Ian Sims

Polysaccharides and oligosaccharides are large complex molecules, made up of different sugars arranged in diverse ways. They usually have a regular backbone or repeating unit but are also likely to contain many branches and structural variations. Dr Ian Sims, a Principal Scientist at IRL, leads the team that specialises in analysing these carbohydrates. 

“We do a huge variety of work here and offer a commercial polysaccharide analysis service that is quite sought-after.

“When we’re analysing a sample for a client, we start with some general colorimetric assays plus proton and carbon NMR^[?], to work out what types of carbohydrates are present. We then move into more specific analyses to work out what the sugars actually are and how they are linked, using techniques such as neutral sugar and glycosyl linkage analysis. Size-exclusion chromatography can tell us how big the molecules are and another method (HPAEC) enables us to determine the sequence of sugars in the polysaccharide."

Once all this information has been gathered, Ian and the team start to piece together the polysaccharide’s molecular structure, using the data as clues. “This is the bit I really like about my job—the puzzle of working out how these carbohydrate molecules are stuck together.

“We are not biologists, but we partner with biologists and work together. When you put our analytical skills alongside their skills and experience, it becomes a very powerful combination. I always look for collaborators who can complement the expertise we have here. 

“What we’ve been doing with a group of biologists at the University of Otago for example, is fantastic. The group have expertise in the microbial communities of the human digestive tract. They are interested in knowing which carbohydrates are being digested by the different bacteria in various parts of the gut. By analysing the oligosaccharides that remain after the carbohydrate has been digested, we can get a good idea of what the bacteria are actually doing.

Ian is often seen riding a bike of some sort. “I’ve been a cyclist most of my life, after I started biking just to get around. I bike to work most days and have done everything in the sport really—touring, racing and mountain biking.

“We enjoy a family ride at weekends and now my wife and I go out with a child each on the back of our two tandems. We can go 40–50 km without too much trouble as long as we stop at a cafe for coffee and cake and ideally a playground too.

“New Zealand is a great place to live. I started out studying plant biology and through an industry placement, was offered a place for a PhD at the University of Wales, but most of my work was done at the nearby Institute of Grassland and Environmental Research in Aberystwyth. From there I was offered jobs at IRL and at the Botany School in Melbourne. I spent six years in Melbourne but Dr Richard Furneaux stayed in touch and kept asking me if I was ready to come to New Zealand yet. Eventually I said yes, and have been here ever since.”