University of Massachusetts Medical School Faculty Publications

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology; Biomedical Imaging Group, Program in Molecular Medicine

Publication Date

2019-09-25

Document Type

Article Preprint

Disciplines

Amino Acids, Peptides, and Proteins | Biochemistry | Biophysics

Abstract

Small molecule fluorescent wheat germ agglutinin (WGA) conjugates are routinely used to demarcate mammalian plasma membranes because they bind to the cell’s glycocalyx. Here we describe the derivatization of WGA with a pH sensitive rhodamine fluorophore (pHRho: pKa = 7) to detect proton channel fluxes and extracellular proton accumulation and depletion from primary cells. We found that WGA-pHRho labeling was uniform, did not appreciably alter the voltage-gating of glycosylated ion channels, and the extracellular changes in pH directly correlated with proton channel activity. Using single plane illumination techniques, WGA-pHRho was used to detect spatiotemporal differences in proton accumulation and depletion over the extracellular surface of cardiomyocytes, astrocytes, and neurons. Because WGA can be derivatized with any small molecule fluorescent ion sensor, WGA conjugates should prove useful to visualize most electrogenic and non-electrogenic events on the extracellular side of the plasma membrane.

Keywords

wheat germ agglutinin, proton channel fluxes, plasma membranes, biophysics

Rights and Permissions

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It is made available under a CC-BY-NC-ND 4.0 International license.

DOI of Published Version

10.1101/781799

Source

bioRxiv 781799; doi: https://doi.org/10.1101/781799. Link to preprint on bioRxiv service.

Related Resources

Now published in The Journal of General Physiology doi: 10.1085/jgp.201912498

Journal/Book/Conference Title

bioRxiv

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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