Show simple item record

dc.contributor.authorLi, Lu
dc.contributor.authorDuhamel, Jean 17:13:57 (GMT) 17:13:57 (GMT)
dc.descriptionThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Macromolecules, copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see
dc.description.abstractAmylose and poly(methyl acrylate) were randomly labeled with pyrene to yield a series of Py-Amylose and Py-PMA constructs, and their ability to form excimer in DMSO was characterized quantitatively by steady-state and time-resolved fluorescence. First, the ratio of the fluorescence intensity of the excimer over that of the monomer, namely the I-E/I-M ratio, was obtained from the fluorescence spectra. Second, the product < k(blob) X N-blob > was obtained from the fluorescence blob model (FBM) analysis of the fluorescence decays. Both I-E/I-M and < k(blob) X N-blob > yielded similar values when expressed in terms of moles of pyrene per backbone atom for Py-Amylose and Py-PMA. Since IE/IM and < k(blob) X N-blob > reflect the efficiency of pyrene excimer formation, the similar behavior observed for both parameters obtained for rigid amylose and flexible PMA could only be rationalised by postulating that amylose adopted a compact helical conformation in DMSO. To confirm whether this was possible, molecular mechanics optimizations were conducted with the HyperChem program on Py-Amylose assuming a helical conformation for amylose in DMSO. Two pyrene labels were found to overlap properly, and thus form excimer efficiently, if they were separated by no more than five anhydroglucose units up and down the amylose helix around the anhydroglucose unit bearing the reference pyrene label. This result suggested that excimer formation would not occur if two pyrene labels were separated by more than 5 + 5 + 1 = 11 anhydroglucose units, in perfect agreement with our findings that < N-blob > obtained from the FBM analysis of the fluorescence decays acquired with the Py-Amylose solutions in DMSO equaled 11 +/- 2. The good agreement between simulations and experiments led to the conclusion that amylose must adopt a helical conformation in DMSO.en
dc.description.sponsorshipNatural Sciences and Engineering Research Council of Canadaen
dc.publisherAmerican Chemical Societyen
dc.subjectTo-End Cyclizationen
dc.subjectCoil-Globule Transitionen
dc.subjectPolymer-Chain Dynamicsen
dc.subjectExcimer Formationen
dc.subjectSolvent Qualityen
dc.titleConformation of Pyrene-Labeled Amylose in DMSO Characterized with the Fluorescence Blob Modelen
dcterms.bibliographicCitationLi, L., & Duhamel, J. (2016). Conformation of Pyrene-Labeled Amylose in DMSO Characterized with the Fluorescence Blob Model. Macromolecules, 49(20), 7965–7974. doi:10.1021/acs.macromol.6b01614en
uws.contributor.affiliation1Faculty of Scienceen

Files in this item


This item appears in the following Collection(s)

Show simple item record


University of Waterloo Library
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4883

All items in UWSpace are protected by copyright, with all rights reserved.

DSpace software

Service outages