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Site‐specific small molecule labeling of an internal loop in JC polyomavirus pentamers using the π‐clamp‐mediated cysteine conjugation

Baccile, Joshua A. and Voorhees, Peter J. and Chillo, Anthony J. and Berry, Madeline and Morgenstern, Robin and Schwertfeger, Tyler J. and Rossi, Francis M. and Nelson, Christian D. S. (2021) Site‐specific small molecule labeling of an internal loop in JC polyomavirus pentamers using the π‐clamp‐mediated cysteine conjugation. ChemBioChem . ISSN 1439-4227. doi:10.1002/cbic.202100188. (In Press)

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The major capsid protein VP1 of JC Polyomavirus assembles into pentamers that serve as a model for studying viral entry of this potentially severe human pathogen. Previously, labeling of viral proteins utilized large fusion proteins or non-specific amine- or cysteine-functionalization with fluorescent dyes. Imaging of these sterically hindered fusion proteins or heterogeneously labeled virions limits reproducibility and could prevent the detection of subtle trafficking phenomena. Here we advance the π-clamp-mediated cysteine conjugation for site-selective fluorescent labeling of VP1-pentamers. We demonstrate a one-step synthesis of a probe consisting of a bio-orthogonal click chemistry handle bridged to a perfluoro-biphenyl π-clamp reactive electrophile by a polyethylene glycol linker. We expand the scope of the π-clamp conjugation by demonstrating selective labeling of an internal, surface exposed loop in VP1. Thus, the π-clamp conjugation offers a general method to selectively bioconjugate tags-of-interest to viral proteins without impeding their ability to bind and enter cells.

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Additional Information:© 2021 Wiley-VCH GmbH. Accepted manuscript online: 20 May 2021; Manuscript accepted: 20 May 2021; Manuscript revised: 19 May 2021; Manuscript received: 20 April 2021. The authors thank all members of the Rossi and Nelson lab for their help in preparing this manuscript and for David Tirrell’s generosity sharing equipment and resources from the Tirrell lab. The authors also thank the Multi User Mass Spectrometry Laboratory at Caltech and Mona Shahgoli for her assistance. This work has been supported by a SUNY Cortland Faculty Research Proposal to C.D.N. and the Jacobs Foundation to J.A.B..
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State University of New YorkUNSPECIFIED
Jacobs FoundationUNSPECIFIED
Subject Keywords:bioorthogonal; click chemistry; fluorescent probes; protein modifications; viruses
Record Number:CaltechAUTHORS:20210527-152005475
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Official Citation:Baccile, J..A., Voorhees, P..J., Chillo, A..J., Berry, M., Morgenstern, R., Schwertfeger, T..J., Rossi, F..M. and Nelson, C..D.S. (2021), Site-specific small molecule labeling of an internal loop in JC polyomavirus pentamers using the π-clamp-mediated cysteine conjugation. ChemBioChem. Accepted Author Manuscript.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109286
Deposited By: Tony Diaz
Deposited On:27 May 2021 22:28
Last Modified:27 May 2021 22:28

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