Classification and characteristics of bacterial glycosaminoglycan lyases, and their therapeutic and experimental applications

ABSTRACT Glycosaminoglycans (GAGs), as animal polysaccharides, are linked to proteins to form various types of proteoglycans. Bacterial GAG lyases are not only essential enzymes that spoilage bacteria use for the degradation of GAGs, but also valuable tools for investigating the biological function and potential therapeutic applications of GAGs. The ongoing discovery and characterization of novel GAG lyases has identified an increasing number of lyases suitable for functional studies and other applications involving GAGs, which include oligosaccharide sequencing, detection and removal of specific glycan chains, clinical drug development and the design of novel biomaterials and sensors, some of which have not yet been comprehensively summarized. GAG lyases can be classified into hyaluronate lyases, chondroitinases and heparinases based on their substrate spectra, and their functional applications are mainly determined by their substrates, with different lyases exhibiting differing substrate selectivity and preferences. It is thus necessary to understand the properties of the available enzymes to determine strategies for their functional application. Building on previous studies and reviews, this Review highlights small yet crucial differences among or within the various GAG lyases to aid in optimizing their use in future studies. To clarify ideas and strategies for further research, we also discuss several traditional and novel applications of GAG lyases.