Volume 60, Issue 16 pp. 8932-8937
Research Article

Bio-adhesive Nanoporous Module: Toward Autonomous Gating

Hyuna Jo

Hyuna Jo

Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan

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Dr. Takashi Kitao

Dr. Takashi Kitao

Department of Advanced Materials Science, Graduate School of Frontier Sciences and Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Chiba, 227-8561 Japan

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Ayumi Kimura

Ayumi Kimura

Institute of Engineering Innovation, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-8656 Japan

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Dr. Yoshimitsu Itoh

Dr. Yoshimitsu Itoh

Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan

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Prof. Dr. Takuzo Aida

Corresponding Author

Prof. Dr. Takuzo Aida

Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan

RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan

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Dr. Kou Okuro

Corresponding Author

Dr. Kou Okuro

Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan

Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China

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First published: 02 February 2021
Citations: 3

Graphical Abstract

A porous covalent organic framework (GlueCOF) carrying guanidinium ion pendants has been developed that can accommodate guests and bind to biopolymers. The strong bio-adhesive nature of GlueCOF was used to noncovalently bind to calmodulin (CaM), which acted as a gating component for the guest-loaded 1D nanopores (CaMCOF⊃guest). The conformational change of the CaM gate upon selective binding with Ca2+ enabled the release of guest molecules.

Abstract

Here we report a bio-adhesive porous organic module (GlueCOF) composed of hexagonally packed 1D nanopores based on a covalent organic framework. The nanopores are densely decorated with guanidinium ion (Gu+) pendants capable of forming salt bridges with oxyanionic species. GlueCOF strongly adheres to biopolymers through multivalent salt-bridging interactions with their ubiquitous oxyanionic species. By taking advantage of its strong bio-adhesive nature, we succeeded in creating a gate that possibly opens the nanopores through a selective interaction with a reporter chemical and releases guest molecules. We chose calmodulin (CaM) as a gating component that can stably entrap a loaded guest, sulforhodamine B (SRB), within the nanopores (CaMCOF⊃SRB). CaM is known to change its conformation on binding with Ca2+ ions. We confirmed that mixing CaMCOF⊃SRB with Ca2+ resulted in the release of SRB from the nanopores, whereas the use of weakly binding Mg2+ ions resulted in a much slower release of SRB.

Conflict of interest

The authors declare no conflict of interest.

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