Partitioning of a polymer into a nanoscopic protein pore obeys a simple scaling law

Liviu Movileanu, Hagan Bayley

Research output: Contribution to journalArticlepeer-review

80 Scopus citations

Abstract

The dependence of the rate on polymer mass was examined for the reaction of four sulfhydryl-directed poly(ethylene glycol) reagents with cysteine residues located in the lumen of the staphylococcal α-hemolysin pore. The logarithms of the apparent rate constants for a particular site in the lumen were proportional to N, the number of repeat units in a polymer chain. The proportionality constant was -(a/D)5/3, where a is the persistence length of the polymer (≈3.5Å) and D is the diameter of the pore. Despite some incongruencies with the assumptions of the derivation, the result suggests that the polymers partition into the lumen of the pore according to the simple scaling law of Daoud and de Gennes, cpore/csolution = exp(-N(a/D)5/3). Therefore, the measured reaction rates yield an estimate of the diameter of the pore and might be applied to determine the approximate dimensions of cavities within other similar proteins.

Original languageEnglish (US)
Pages (from-to)10137-10141
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume98
Issue number18
DOIs
StatePublished - Aug 28 2001
Externally publishedYes

ASJC Scopus subject areas

  • General

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