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Journal of Biomedical Optics • Open Access

Kinetics of a single cross-bridge in familial hypertrophic cardiomyopathy heart muscle measured by reverse Kretschmann fluorescence
Author(s): Prasad Mettikolla; Nils Calander; Rafal Luchowski; Ignacy Gryczynski; Zygmunt Karol Gryczynski; Julian Borejdo

Paper Abstract

Familial hypertrophic cardiomyopathy (FHC) is a serious heart disease that often leads to a sudden cardiac death of young athletes. It is believed that the alteration of the kinetics of interaction between actin and myosin causes FHC by making the heart to pump blood inefficiently. We set out to check this hypothesis ex vivo. During contraction of heart muscle, a myosin cross-bridge imparts periodic force impulses to actin. The impulses are analyzed by fluorescence correlation spectroscopy (FCS) of fluorescently labeled actin. To minimize observation volume and background fluorescence, we carry out FCS measurements in surface plasmon coupled emission mode in a reverse Kretschmann configuration. Fluorescence is a result of near-field coupling of fluorophores excited in the vicinity of the metal-coated surface of a coverslip with the surface plasmons propagating in the metal. Surface plasmons decouple on opposite sides of the metal film and emit in a directional manner as far-field p-polarized radiation. We show that the rate of changes of orientation is significantly faster in contracting cardiac myofibrils of transgenic mice than wild type. These results are consistent with the fact that mutated heart muscle myosin translates actin faster in in vitro motility assays.

Paper Details

Date Published: 1 January 2010
PDF: 9 pages
J. Biomed. Opt. 15(1) 017011 doi: 10.1117/1.3324871
Published in: Journal of Biomedical Optics Volume 15, Issue 1
Show Author Affiliations
Prasad Mettikolla, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)
Nils Calander, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)
Rafal Luchowski, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)
Ignacy Gryczynski, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)
Zygmunt Karol Gryczynski, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)
Julian Borejdo, Univ. of North Texas Health Science Ctr. at Fort Worth (United States)


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