Yuguang Du

State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P.R. China

With the development of glycobiology, glycan structures and their biological functions were revealed, and a variety of functional glycan products have been widely used in food, medicine, breeding and agriculture. So far, more than 500 kinds of carbohydrate drugs, health foods containing functional glycans and other related glycan products have been sold on the market. Glycan structures are usually far more complicated than that of lipids and proteins, which greatly restricts the large-scale glycan production as well as their molecular regulation understanding. Glycans are mainly produced by natural polysaccharide degradation or chemical synthesis. However, polysaccharide degradation currently relies on acidic or alkaline hydrolysis for lack of glucosidases, and such chemical methods not only cause severe environmental pollution, but fail to obtain highly-pure product in most cases. As for the chemical synthesis of glycans, the sophisticated process is paralleled with low yields, byproducts and high cost. And how to explain the molecular regulation mechanism of functional glycans is another challenge in the glyco-biological field.

Aiming to the above-mentioned, our team focus on the following research:

1. To establish a library of glucosidases for natural polysaccharide degradation. The library will not only cover the 195 classes of reported glucosidases, but those to be identified by using high-throughput screening system. These glucosidases will be used for the controlled degradation and clean production of glycans. Until now, our library have collected about 50 engineered strains expressing glucosidases.
2. To establish a library of oligosaccharides, which are produced from the following two major sources: a) the degraded products of polysaccharides from natural herb, Tibetan medicine and other plants; b) the separated oligosaccharides from milk of human, cattle, sheep and other mammalians. Currently, this library includes more than 1000 oligosaccharide portions.
3. To establish a screening platform to explore the molecular regulation mechanism of functional glycans. To screen functional glycans, this platform will be based on the enteral nutrition, brain development, lipid and glucose metabolism disorders, aging and other pathological responses.
4. To establish a platform to develop the new glyco-engineering products. Combined with the established glucosidase library, a standardized processing protocol will be set up for natural polysaccharide degradation, separation, purification and so on. Also, an automated synthesis platform will be constructed for large-scale glycan preparation on the basis of microarray chip technology.