Light-Emitting Probes for Labeling Peptides

Abstract

SUMMARY Peptides are versatile biopolymers composed of 2–100 amino acid residues that present a wide range of biological functions and constitute potential therapies for numerous diseases, partly due to their ability to penetrate cell membranes. However, their mechanisms of action have not been fully elucidated due to the lack of appropriate tools. Existing light-emitting probes are limited by their cytotoxicity and large size, which can alter peptide structure and function. Here, we describe the available fluorescent, bioluminescent, and chemiluminescent probes for labeling peptides, with a focus on minimalistic options.

Human gut metagenomic mining reveals an untapped source of peptide antibiotics

“…The peptide antibiotic polymyxin B was used as a positive control in our studies 21 . In summary, SEPs did not permeabilize the outer membrane of bacteria to the level previously reported for AMPs 7,32 or EPs 21 , indicating that the mechanism of action of SEPs might be independent of outer membrane permeabilization.…”

“…Current methods used to discover new molecules rely primarily on prospection of naturally occurring organisms, which is slow and upredictable as it relies on trial-and-error experimentation. Additional engineering of AMPs has leveraged heuristics whereby amino acid residues substitutions are introduced [7][8][9][10][11] , guided by alterations in physicochemical feature determinants known to contribute to membrane targeting and, ultimately, antimicrobial activity 4 . Recently, advances in machine learning 12,13 and methods 14 such as generic algorithms 15 and pattern recognition algorithms 16,17 have yielded improved peptides.…”

Enhancing proline-rich antimicrobial peptide action by homodimerization: influence of bifunctional linker

“…47 19 F NMR showed that such linkers possess significant rigidity and lipophilicity. 48 By using fluorescent reporters, 49,50 we further assessed their modes of action involving outer and inner membrane permeability and change in membrane potential. The HIM imaging analysis further identified the bacterial morphological changes caused by PrAMPs 6 and 7 .…”

Evidence for the Formation of 1,2-Dioxetane as a High-Energy Intermediate and Possible Chemiexcitation Pathways in the Chemiluminescence of Lophine Peroxides

“…If the role of triplet states is confirmed, this should be considered in the future use of lophine silylperoxides as sensors for biological systems . The conjugation of a lophine silylperoxide to a peptide or protein would allow the use of this class of peroxides as CL probes for labeling biomolecules . While singlet excited states are important for analytical and labeling purposes, , triplet states generated in situ could be used for assessing biological oxidation through chemiexcitation instead of light absorption, also known as “dark” photochemistry.…”