Modular, multifunctional nanoparticle-based bioconjugate for realtime visualization of cellular membrane potential
Inventors
Delehanty, James B. • Stewart, Michael H. • Nag, Okhil • Deschamps, Jeffrey R. • Susumu, Kimihiro • Oh, Eunkeu • Field, Lauren D. • Efros, Alexander L. • Huston, Alan L. • Medintz, Igor L. • Dawson, Philip E.
Assignees
Publication Number
US-11287430-B2
Publication Date
2022-03-29
Expiration Date
2038-01-29
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Abstract
A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.
Core Innovation
The invention provides a modular, multifunctional nanoparticle-based electron donor-acceptor bioconjugate for realtime detection of changes in cellular membrane potential. The construct includes a photoluminescent nanoparticle electron donor, a modular multidomain membrane insertion peptide with a nanoparticle association domain, motifs mediating peptide insertion into the plasma membrane, and controlled attachment points for an electron acceptor, as well as an electron acceptor. The rate of electron transfer between donor and acceptor is modulated by membrane potential changes, which is reported via measurable changes in donor photoluminescence.
The problem being solved addresses the limitations of existing methods for sensing cellular membrane potential. Current electro-optical sensors based on voltage-sensitive dyes suffer from poor solubility, nonspecific labeling, poor photostability, and cytotoxicity. Molecular wire-based sensors require complex synthesis, use prone fluorophores, and complicated molecular bridges. These issues significantly limit the practicality and effectiveness of available membrane potential sensing technologies.
The described construct enables controlled assembly of quantum dot donors with modular peptides and electron acceptors such as C60 fullerene, where peptide design controls electron acceptor distance, tuning the electron transfer rate. This allows efficient and sensitive optical detection of membrane potential changes, demonstrated by cellular membrane insertion and real-time photoluminescence changes in response to membrane depolarization.
Claims Coverage
The patent contains one independent claim that defines the core inventive features of the construct for detecting cellular membrane potential.
Construct comprising nanoparticle electron donor and modular peptide
The construct includes a nanoparticle operable as an electron donor, a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle.
Peptide selection from defined sequences
The modular peptide is selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3.
The claims cover a nanoparticle-based construct with modular peptides that enable membrane insertion and control of electron acceptor positioning, providing a system for detecting membrane potential through modulation of electron transfer and photoluminescence.
Stated Advantages
Amenable to covalent and noncovalent attachment strategies, enabling flexible peptide assembly.
Modular design allowing flexibility for iterative development and testing of peptide domains.
Capability to assemble various nanoparticles with multifunctional peptides for tunable electron transfer rates.
Rapid and high affinity peptide assembly to quantum dots without complex chemistries.
Fast cellular membrane labeling with the conjugates, enabling efficient experimental workflows.
Distance-dependent electron transfer allowing simplified design without conductive peptide linkers.
Superior photostability compared to traditional voltage-sensitive dyes, permitting longer imaging times.
Large two-photon action cross section of quantum dots makes the constructs suitable for deep tissue imaging.
Controllable peptide valence on nanoparticle surfaces to tune donor quenching efficiency.
Documented Applications
Imaging and optical recording of electrical activity in cultured cells, tissue slices, whole tissues, and animals.
Application to electrically active cells such as neurons and muscle cells for membrane potential sensing.
Potential use in quantum dot-based LED cells where tuning of luminescence by an electric field is desired.
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