Mucin O-glycan microarrays.

The study of mucin O-glycan recognition by glycan-binding proteins has been a challenging area of research at the interface of chemistry and biology. Compared with N-glycans, the development of methods for mucin O-glycans has lagged behind and underrepresentation of O-glycans in any of the current microarray libraries have hampered their application in O-glycan recognition studies. A major reason is that, thus far, there has not been a universal O-glycanase for enzymatic release of O-glycans from mucins. Methods of chemical release result in degradation or modification of the core regions. Therefore, isolated O-glycans have been very limited while chemical/enzymatic synthesis has been slow. As for other types of glycans, a variety of approaches have been developed for construction of arrays using different strategies to overcome the limitation of direct immobilization of glycans onto solid matrices. In this presentation, we overview the current state of play in the construction of O-glycan libraries obtained after their release from mucin glycoproteins and from chemical and chemoenzymatic synthesis for microarray construction using non-covalent and covalent immobilization, and highlight their applications.