Globotriose‐Functionalized Gold Nanoparticles as Multivalent Probes for Shiga‐like Toxin

Abstract

Compared to monovalent carbohydrates, multivalent carbohydrate ligands exhibit significantly enhanced binding affinities to their interacting proteins. Here, we report globotriose (P(k) ligand)-functionalized gold nanoparticle (AuNP) probes for the investigation of multivalent interactions with the B(5) subunit of Shiga-like toxin I (B-Slt). Six P(k)-ligand-encapsulated AuNPs (P(k)-AuNPs) of varying particle size and linker length were synthesized and evaluated for their potential as multivalent affinity probes by using a surface plasmon resonance competition assay. The affinity of these probes for the interacting proteins was greatly affected by nanoparticle size, linker length, and ligand density on nanoparticle surface. For example, the 20-nm 20-P(k)-l-AuNP, which had a relatively long linker showed a >10(8)-fold increase in affinity compared with the mono P(k) ligand. This intrinsic high-affinity AuNP probe specifically captured the recombinant B-Slt from Escherichia coli lysate, and the resulting purity of the B-Slt was >95 %. We also developed a robust P(k)-AuNP-based detection method for Slt-I by combining the technique with silver enhancement.

Characterization of Meiothermus taiwanensis Galactokinase and its Use in the One‐Pot Enzymatic Synthesis of Uridine Diphosphate‐Galactose and the Chemoenzymatic Synthesis of the Carbohydrate Antigen Stage Specific Embryonic Antigen‐3

“…[35] The design and synthesis of multivalent ligands to block interactions between toxins and their cell-surface receptors shows potential in drug development. [36] As shown in Scheme 2, to simplify the synthetic process of Gb3, the reaction was performed in Scheme 2. A one-pot, three-enzyme system for the synthesis of globotriose.…”

“…2,3,4,6-Tetra-O-acetyl-a-d-galactopyranosyl bromide 9 [33] (181 mg, 0.44 mmol), glycosyl acceptor 8 (280 mg, 0.487 mmol), silver oxide (154 mg, 0.664 mmol), and 2-aminoethyl diphenylborinate 12 [36] (22 mg, 0.1 mmol) were added to a round-bottom flask under a nitrogen atmosphere. Dry acetonitrile (10 mL) was added, and the resulting mixture was stirred at 70 8C for 2 h. The reaction mixture was filtered, and the resulting crude material was purified by silica gel chromatography (hexane/EtOAc = 3:1).…”

Glyconanoparticles for colorimetric bioassays

“…Chien et al have prepared two derivatives of P k with different chain lengths and self-assembled these onto gold nanoparticles of differing sizes (4, 13 and 20 nm). 81 These glyconanoparticles were used to assess the binding affinity towards the shiga-like toxin with the view to develop a surface plasmon resonance competition assay. The results obtained show that a longer chain length enhances the binding affinity of the P k moiety.…”

Fabrication of Highly Stable Glyco‐Gold Nanoparticles and Development of a Glyco‐Gold Nanoparticle‐Based Oriented Immobilized Antibody Microarray for Lectin (GOAL) Assay

“…[19] Moreover, we determined that globotriose (Gb3 or blood group antigen, P k )-coated AuNPs with different particle sizes containing 60 to 1970 sugars on the surface are inhibitors of the B subunit of Shiga-like toxin (Slt-1). [25] SPR analysis revealed that the relative potencies of each sugar ranged from approximately 1300 for a 4 nm particle with a shorter linker to approximately 228 000 for a 20 nm particle with a longer linker. Thus, glyco-AuNP aggregation could be tuned for use as a newer screening method for monitoring the bond-forming activities of enzymes.…”