Self-Assembling Lectin Nano-Block Oligomers Enhance Binding Avidity to Glycans

Abstract

Lectins, carbohydrate-binding proteins, are attractive biomolecules for medical and biotechnological applications. Many lectins have multiple carbohydrate recognition domains (CRDs) and strongly bind to specific glycans through multivalent binding effect. In our previous study, protein nano-building blocks (PN-blocks) were developed to construct self-assembling supramolecular nanostructures by linking two oligomeric proteins. A PN-block, WA20-foldon, constructed by fusing a dimeric four-helix bundle de novo protein WA20 to a trimeric foldon domain of T4 phage fibritin, self-assembled into several types of polyhedral nanoarchitectures in multiples of 6-mer. Another PN-block, the extender PN-block (ePN-block), constructed by tandemly joining two copies of WA20, self-assembled into cyclized and extended chain-type nanostructures. This study developed novel functional protein nano-building blocks (lectin nano-blocks) by fusing WA20 to a dimeric lectin, Agrocybe cylindracea galectin (ACG). The lectin nano-blocks self-assembled into various oligomers in multiples of 2-mer (dimer, tetramer, hexamer, octamer, etc.). The mass fractions of each oligomer were changed by the length of the linkers between WA20 and ACG. The binding avidity of the lectin nano-block oligomers to glycans was significantly increased through multivalent effects compared with that of the original ACG dimer. Lectin nano-blocks with high avidity will be useful for various applications, such as specific cell labeling.

A Computational and Chemical Design Strategy for Manipulating Glycan‐Protein Recognition

“…However, their relatively low binding affinity toward glycans has hampered the application. [ 34 , 35 ] With engineered PhoSL variants of higher binding affinity in hand, we aimed to explore the utility in glycan detection and imaging. The WT, W28 mut , and W28A PhoSL were individually conjugated with biotin.…”

What is allosteric regulation? Exploring the exceptions that prove the rule!

“…A unique question associated with a large ligand ( e.g ., a protein–protein or a protein–DNA interface) is whether a large ligand that makes multiple contacts across a large binding interface can include a through-protein energetic coupling between those multiple contacts. This idea of energetic coupling in a multivalent interaction ( 115 , 116 ) can be evaluated by dividing that large ligand into fragments. For example, a DNA ligand might be divided into two short DNA ligands representing different contacts with the protein.…”

Extending Janus lectins architecture: characterization and application to protocells

“…Therefore, fine-tuning the specificity or the valency of lectins is a promising approach for obtaining novel tools. Synthetic biology strategies, such as the engineering of protein architecture, bring novel possibilities for lectin applications (Fettis et al 2019; Irumagawa et al 2022; Oh et al 2022; Ramberg et al 2021; Ross et al 2019). Lectin engineering is a novel domain of synthetic glycobiology (Terada et al 2016; Ward et al 2021) and it can be performed at different levels, from glycan specificity to supramolecular architecture.…”