Self-assembled monolayers of globotriaosylceramide (Gb3) mimics: surface-specific affinity with shiga toxins

• Published in: Analytical biochemistry 2002-11, Vol.310 (1), p.27-35
• Main Authors: Miura, Yoshiko, Sasao, Yuuki, Dohi, Hirofumi, Nishida, Yoshihiro, Kobayashi, Kazukiyo
• Format: Article
• Language: English
• Subjects: Adsorption; Biomimetic Materials - chemistry; Biomimetic Materials - metabolism; Carbohydrate Conformation; Carbohydrate Sequence; Computer Simulation; Globotriaosylceramide; Gold - chemistry; Kinetics; Models, Molecular; Molecular recognition; Molecular Sequence Data; Oligosaccharides - chemistry; Protein Binding; Quartz crystal microbalance; Self-assembled monolayers; Shiga toxin; Shiga Toxin 1 - metabolism; Shiga Toxin 2 - metabolism; Spectroscopy, Fourier Transform Infrared - methods; Substrate Specificity; Surface Properties; Trihexosylceramides - chemistry; Trihexosylceramides - metabolism
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/S0003-2697(02)00318-4

Self-assembled monolayers (SAMs) of Gb3 mimics having different lengths of alkyl chains were prepared on gold surfaces, and their interactions with galactose-specific lectin (RCA 120) and Shiga toxins (Stxs) were investigated by a quartz crystal microbalance (QCM) in aqueous solutions. Their interaction with RCA 120 was enhanced owing to the “cluster effect,” regardless of the alkyl chain length of the SAMs. The interaction with Stxs was dependent on the alkyl chain length of Gb3 mimics. Stx-1 and Stx-2 showed a stronger affinity to the Gb3C2 SAM with ethyl disulfide and to the Gb3C10 with decyl disulfide, respectively. Gb3 glycoconjugate polymer with no alkyl spacer inhibited the adsorption of Stx-1 to Gb3C10 SAM but did not inhibit the adsorption of Stx-2 to Gb3C10 SAM. The results suggest that the alkyl chain of the glycolipid takes part in the binding to Stx-2 but not to Stx-1, which is also supported by the computer simulation of Stx-1 with a Gb3 model substance.