Nanoparticle-enhanced activity of a potassium channel-blocking peptide
Inventors
Delehanty, James B. • Muroski, Megan • Oh, Eunkeu • Deschamps, Jeffrey R.
Assignees
Publication Number
US-11617800-B2
Publication Date
2023-04-04
Expiration Date
2040-09-10
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Abstract
A nanoparticle (NP)-peptide conjugate provides efficient steric hindrance/blockage of cellular membrane potassium (K+) channels to mediate depolarization of cellular membrane potential.
Core Innovation
The invention provides a nanoparticle (NP)-peptide conjugate that efficiently sterically hinders or blocks cellular membrane potassium (K+) channels to mediate depolarization of the cellular membrane potential. The conjugate comprises a gold nanoparticle bound to a stable derivative of the peptide tertiapin (TPN), termed TPN-Q, which specifically blocks inwardly-rectifying potassium (Kir) channels to alter membrane potential. The TPN-Q peptide is conjugated to the gold nanoparticle surface via a spacer sequence to maintain its functional interaction with the channel.
The problem addressed arises from the need for improved potassium channel blockers. Existing drugs that block K+ channels are nonspecific, exhibit a range of binding affinities, off-target effects, and often irreversible binding. The native TPN peptide is unstable due to an oxidizable methionine residue, which limits its therapeutic use. The invention overcomes these challenges by conjugating a stable TPN-Q peptide to gold nanoparticles, enhancing peptide stability and augmenting the channel-blocking efficacy compared to free peptide.
The conjugated AuNP-TPN-Q complex shows 2- to 3-fold greater depolarization activity in differentiated neuron-like PC-12 cells compared to free TPN-Q peptide, demonstrating faster and more efficient kinetics in modulating membrane potential. The spacer attachment on the nanoparticle surface ensures effective binding without steric hindrance. Additionally, the complex's activity is reversible through thermal dissociation induced by laser heating, a feature not present with free peptide alone.
Claims Coverage
The patent contains one independent claim describing a construct, with inventive features focusing on the composition and conjugation of components.
Gold nanoparticle conjugated to a peptide comprising SEQ ID NO: 1 and a spacer sequence
A construct comprising a gold nanoparticle chemically conjugated to a peptide that includes the stable TPN-Q peptide sequence (SEQ ID NO: 1) combined with a spacer sequence. The spacer sequence is appended to facilitate effective conjugation and functional presentation of the peptide on the nanoparticle surface.
The claims cover the construct formed by the gold nanoparticle conjugated to a specifically sequenced peptide including TPN-Q and a spacer, which together provide enhanced potassium channel blocking activity beyond that of the free peptide.
Stated Advantages
Appending the TPN-Q peptide to a gold nanoparticle carrier enhances and augments the biological activity of the peptide, improving potassium channel blocking efficacy.
The AuNP-TPN-Q conjugate labeled with dye allows for easy tracking and visualization of binding to the plasma membrane.
Documented Applications
Nanoparticle-based therapeutics targeting potassium channels for activation of neurons and muscle cells to enable non-invasive brain and muscle cell stimulation through controlled modulation of membrane potential.
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