High‐Specificity Affinity Reagents for the Detection of Glycan Sialylation

Abstract

Glycans have distinct properties that make them appealing as disease biomarker targets, and novel highly specific reagents are essential to overcome current limitations in the discovery and exploitation of disease‐related glycans.Lectenz® Bio is engineering glycan‐processing enzymes into catalytically inactive, high affinity glycan binding reagents with tunable specificities. These novel lectin‐like, enzyme‐derived reagents called Lectenz® are being developed for a variety of glycan detection and enrichment applications including affinity chromatography, Western blot, and immunohistochemistry. The conversion of such enzymes into affinity reagents is facilitated by computationally‐guided directed evolution. Using site‐directed mutagenesis and yeast display selection of a site‐saturation mutagenesis library, multiple Lectenz® candidates can be identified.Here we present two novel sialic acid recognizing Lectenz® engineered from a sialidase enzyme: 1) the pan‐specific sialic acid reagent, Sia‐PS1 Lectenz®, which recognizes sialic acid in a linkage independent manner; and 2) the Sia‐3S1 Lectenz®, which is specific for α2,3‐linked sialoglycans. The data demonstrate that the Sia‐PS1 Lectenz® reagent recognizes glycans terminating in α2,3‐, α2,6‐, and α2,8‐linked sialic acid sequences, but not Gal‐terminating sequences. With the Sia‐3S1 Lectenz®, we demonstrate binding to Neu5Acα2,3Galβ1,4Glc, but not Neu5Acα2,6 Galβ1,4Glc or Galβ1,4Glc.Support or Funding InformationNational Institutes of Health (R41GM113351)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.