In vitro sliding of actin filaments labelled with single quantum dots.
We recently refined the in vitro motility assay for studies of actomyosin function to achieve rectified myosin induced sliding of actin filaments. This paves the way, both for detailed functional studies of actomyosin and for nanotechnological applications. In the latter applications it would be desirable to use actin filaments for transportation of cargoes (e.g., enzymes) between different predetermined locations on a chip. We here describe how single quantum dot labelling of isolated actin filaments simultaneously provides handles for cargo attachment and bright and photostable fluorescence labels facilitating cargo detection and filament tracking. Labelling was achieved with preserved actomyosin function using streptavidin-coated CdSe quantum dots (Qdots). These nanocrystals have several unique physical properties and the present work describes their first use for functional studies of isolated proteins outside the cell. The results, in addition to the nanotechnology developments, open for new types of in vitro assays of isolated biomolecules.
Månsson
Alf
A
Department of Chemistry and Biomedical Sciences, University of Kalmar, SE-39182 Kalmar, Sweden. alf.mansson@hik.se
Sundberg
Mark
M
Balaz
Martina
M
Bunk
Richard
R
Nicholls
Ian A
IA
Omling
Pär
P
Tågerud
Sven
S
Montelius
Lars
L
D008841:Actin Cytoskeleton / Q000737:chemistry*; D000199:Actins / Q000737:chemistry*; D000205:Actomyosin / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002465:Cell Movement; D005456:Fluorescent Dyes / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008853:Microscopy; D008856:Microscopy, Fluorescence; D009218:Myosins / Q000737:chemistry; D011485:Protein Binding; D011817:Rabbits; D013997:Time Factors
D000199:Actins; D005456:Fluorescent Dyes; D000205:Actomyosin; D009218:Myosins