大澤　重仁    Department   Research Institutes and Facilities, Research Institutes and Facilities    Position
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	Direct Observation of Cell Surface Sialylation by Atomic Force Microscopy Employing Boronic Acid–Sialic Acid Reversible Interaction
Journal	Formal name：Analytical chemistry Abbreviation：Anal Chem ISSN code：00032700/15206882
Domestic / Foregin	Foregin
Volume, Issue, Page	92(17),pp.11714-11720
Author and coauthor	Shigehito Osawa, Akira Matsumoto, Yukie Maejima, Toshihiro Suzuki, Yuji Miyahara, Hidenori Otsuka
Authorship	Lead author
Publication date	2020/07/29
Summary	Tracing cell surface sialylation dynamics at a scale of the glycolipoprotein microdomain (lipid rafts) formations remains an intriguing challenge of cellular biology. Here, we demonstrate that this goal is accessible, taking advantage of a boronic acid (BA)-based reversible molecular recognition chemistry. A BA-end-functionalized poly(ethylene glycol) was decorated onto an atomic force microscopy (AFM) cantilever, which provided a dynamic and sialic acid (SA)-specific imaging mode. Using this technique, we were able to heat map the SA expression levels not only on protein-decorated substrates but also directly on the cell surfaces, with a submicrometer scale resolution that may be relevant to that of the lipid rafts formation. The SA specificity and the binding reversibility of the probe were confirmed from its pH-dependent characteristics and an inhibition assay using free state SA. This finding may provide a noninvasive means for assessing a variety of SA-involved glycosylation dynamics spanning from physiology to pathology.
DOI	https://doi.org/10.1021/acs.analchem.0c01705