Biglycan is a covalent conjugate between protein and carbohydrate that is called a proteoglycan. Biglycan is a component of extracellular matrix and is important for normal bone growth. While there exists atomic-resolution three-dimensional structure of the protein component, such information is lacking for the carbohydrate component. To better understand the relation between the structure and function of biglycan, we are using physics-based computational methods to construct an atomic-resolution model of the complete protein-carbohydrate conjugate.
Glycosaminoglycans (GAGs) are linear biological polymers consisting of a repeating sequence of two simple sugars, and are a major carbohydrate component of proteoglycans. GAGs are attached to proteoglycan core proteins by a linear chain of four particular simple sugars, but there is little experimental information on the conformational properties of this linkage. We are applying computer modeling to determine the different conformations the linkage can assume, and which conformation is the most common.
Dermatan sulfate is a glycosaminoglycan (GAG) that is found covalently attached to proteoglycans. The variability in its biological sequence with regard to length and modification with sulfate groups makes it difficult to obtain pure samples for experimental study. We are using atomic-resolution molecular simulations to characterize the flexibility of this polymer and how the addition of sulfate groups affects this flexibility.