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Fiber depolymerization

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Turner, Matthew S. , Agarwal, G., Jones, C. W., Wang, J. C., Kwong, S., Ferrone, F. A., Josephs, R. and Briehl, R. W.. (2006) Fiber depolymerization. Biophysical Journal, Vol.91 (No.3). pp. 1008-1013. ISSN 0006-3495

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Official URL: http://dx.doi.org/10.1529/biophysj.105.075333

Abstract

Depolymerization is, by definition, a crucial process in the reversible assembly of various biopolymers. It may also be an important factor in the pathology of sickle cell disease. If sickle hemoglobin fibers fail to depolymerize fully during passage through the lungs then they will reintroduce aggregates into the systemic circulation and eliminate or shorten the protective delay (nucleation) time for the subsequent growth of fibers. We study how depolymerization depends on the rates of end- and side-depolymerization, kend and kside, which are, respectively, the rates at which fiber length is lost at each end and the rate at which new breaks appear per unit fiber length. We present both an analytic mean field theory and supporting simulations showing that the characteristic fiber depolymerization time View the MathML source depends on both rates, but not on the fiber length L, in a large intermediate regime 1 much less-than ksideL2/kend much less-than (L/d)2, with d the fiber diameter. We present new experimental data which confirms that both mechanisms are important and shows how the rate of side depolymerization depends strongly on the concentration of CO, acting as a proxy for oxygen. Our theory remains rather general and could be applied to the depolymerization of an entire class of linear aggregates, not just sickle hemoglobin fibers.

Item Type:

Journal Article

Subjects:

Q Science > QH Natural history > QH301 Biology

Divisions:

Faculty of Science > Physics

Library of Congress Subject Headings (LCSH):

Biopolymers -- Separation, Nucleation, Polymerization, Carbon dioxide -- Physiological effect

Journal or Publication Title:

Biophysical Journal

Publisher:

Biophysical Society

ISSN:

0006-3495

Official Date:

August 2006

Dates:

Date	Event
August 2006	Published

Volume:

Vol.91

Number:

No.3

Page Range:

pp. 1008-1013

Identification Number:

10.1529/biophysj.105.075333

Status:

Peer Reviewed

Access rights to Published version:

Open Access

Funder:

National Heart, Lung, and Blood Institute

Grant number:

HL58512 (NHLBI), HL22654 (NHLBI)

References:

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URI:

http://wrap.warwick.ac.uk/id/eprint/922

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