Glycochips from polyanionic glycopolymers as tools for detecting Shiga toxins.
An alternating layer-by-layer adsorption methodology was applied to the assembly of glycochips by using synthetic polyanionic glycopolymers. Three glycochips carrying globobioside (Gb(2)), beta-lactoside (beta-Lac), or alpha-D-mannoside (alpha-Man) residues were prepared, and used for the detection of Shiga toxins, Stx-1 and Stx-2, by using surface plasmon resonance (SPR). Using this method, we could confirm that both Stx-1 and Stx-2 show binding specificity for the Gb(2) glycochip as well as a weak affinity for the beta-Lac glycochip. The affinity constants of these toxins depended strongly on the sugar content of the Gb(2) polymer used to prepare the glycochip. Greater affinity was observed for chips with a higher sugar content (up to 43 %) in the Gb(2) glycopolymer. The maximal affinity constants of Stx-1 and Stx-2 (K(a)=10(8)-10(9) M(-1)) enabled highly sensitive and facile analysis (10 ng mL(-1), 30 min). When Gb(2) glycopolymers were used as competitors, Stx-1 and Stx-2 behaved differently from one another in terms of their SPR response; this allowed us to perform discriminative analysis between the two toxins.
Uzawa
Hirotaka
H
Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba 305-8565, Japan. h.uzawa@aist.go.jp
Ito
Hiroki
H
Neri
Paola
P
Mori
Hiroshi
H
Nishida
Yoshihiro
Y
D000327:Adsorption; D000838:Anions / Q000737:chemistry; D006031:Glycosylation; D007700:Kinetics; D046208:Microchip Analytical Procedures / Q000379:methods*; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D022603:Shiga Toxins / Q000032:analysis* / Q000737:chemistry; D020349:Surface Plasmon Resonance
D000838:Anions; D011108:Polymers; D022603:Shiga Toxins