Defining the Specificity of Blood-Group-Binding Lectins Through Microarray Analysis

The assessment of blood group antigens is critical to transfusion medicine practice, as accurately identifying these antigens in both donors and patients is key to ensuring safe transfusions. Although plant lectins have long been used to aid in the identification of many carbohydrate-based blood group antigens, recent research has shown that a family of mammalian proteins known as galectins can also recognize and bind to blood group antigens. However, determining the fine specificity of lectins toward these antigens is challenging because of the structural complexity of the antigens and past limitations in the resources available to characterize their interactions in detail. To overcome this, the Consortium for Functional Glycomics (CFG) developed glycan microarrays composed of chemoenzymatically defined glycans, including a wide range of blood group antigens. This platform enables precise analysis of lectin-antigen interactions and uses additional glycans as controls to refine the specificity of these interactions. We will describe the use of this platform to characterize the specificity and relative affinity of lectins for blood group and related glycans.