Mobile Molecules: Reactivity Profiling Guides Faster Movement on a Cysteine Track.
Angew Chem Weinheim Bergstr Ger
; 135(21): e202300890, 2023 May 15.
Article
em En
| MEDLINE
| ID: mdl-38529338
ABSTRACT
We previously reported a molecular hopper, which makes sub-nanometer steps by thiol-disulfide interchange along a track with cysteine footholds within a protein nanopore. Here we optimize the hopping rate (ca. 0.1â
s-1 in the previous work) with a view towards rapid enzymeless biopolymer characterization during translocation within nanopores. We first took a single-molecule approach to obtain the reactivity profiles of individual footholds. The pK a values of cysteine thiols within a pore ranged from 9.17 to 9.85, and the pH-independent rate constants of the thiolates with a small-molecule disulfide varied by up to 20-fold. Through site-specific mutagenesis and a pH increase from 8.5 to 9.5, the overall hopping rate of a DNA cargo along a five-cysteine track was accelerated 4-fold, and the rate-limiting step 21-fold.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Weinheim Bergstr Ger
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2023
Tipo de documento:
Article