Biomaterial Database

Microsecond rotational dynamics of actin: spectroscopic detection and theoretical simulation. 1996

E Prochniewicz, and Q Zhang, and E C Howard, and D D Thomas

Department of Biochemistry University of Minnesota Medical School, Minneapolis 55455, USA.

We have investigated the microsecond rotational dynamics of F-actin with transient phosphorescence anisotropy (TPA) spectroscopy, and analyzed the data to determine the relative contributions from rigid-body rotations and from intrafilament bending and twisting, using a theoretical model developed for DNA dynamics by Schurr and co-workers. The fits of the data to the model were constrained by independently determining the orientation of the dye's absorption dipole (by transient absorption anisotropy, TAA) and the actin filament length distribution (by electron microscopy). We conclude that (1) the Schurr theory enables calculation of the torsional flexibility of actin independent of any contribution from rigid body rotations of the whole filament, (2) the TPA decays cannot be explained by rigid-body or bending rotations, but reflect primary twisting motions within actin filaments, and (3) the dynamic properties of actin filaments are best ascribed to a continuous elasticity. This analysis establishes a firm methodological foundation for future studies of the effects or perturbations of the dynamics of actin on its functional properties.

UI	MeSH Term	Description	Entries
D008163	Luminescent Measurements	Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.	Bioluminescence Measurements,Bioluminescent Assays,Bioluminescent Measurements,Chemiluminescence Measurements,Chemiluminescent Assays,Chemiluminescent Measurements,Chemoluminescence Measurements,Luminescence Measurements,Luminescent Assays,Luminescent Techniques,Phosphorescence Measurements,Phosphorescent Assays,Phosphorescent Measurements,Assay, Bioluminescent,Assay, Chemiluminescent,Assay, Luminescent,Assay, Phosphorescent,Assays, Bioluminescent,Assays, Chemiluminescent,Assays, Luminescent,Assays, Phosphorescent,Bioluminescence Measurement,Bioluminescent Assay,Bioluminescent Measurement,Chemiluminescence Measurement,Chemiluminescent Assay,Chemiluminescent Measurement,Chemoluminescence Measurement,Luminescence Measurement,Luminescent Assay,Luminescent Measurement,Luminescent Technique,Measurement, Bioluminescence,Measurement, Bioluminescent,Measurement, Chemiluminescence,Measurement, Chemiluminescent,Measurement, Chemoluminescence,Measurement, Luminescence,Measurement, Luminescent,Measurement, Phosphorescence,Measurement, Phosphorescent,Measurements, Bioluminescence,Measurements, Bioluminescent,Measurements, Chemiluminescence,Measurements, Chemiluminescent,Measurements, Chemoluminescence,Measurements, Luminescence,Measurements, Luminescent,Measurements, Phosphorescence,Measurements, Phosphorescent,Phosphorescence Measurement,Phosphorescent Assay,Phosphorescent Measurement,Technique, Luminescent,Techniques, Luminescent
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D000199	Actins	Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.	F-Actin,G-Actin,Actin,Isoactin,N-Actin,alpha-Actin,alpha-Isoactin,beta-Actin,gamma-Actin,F Actin,G Actin,N Actin,alpha Actin,alpha Isoactin,beta Actin,gamma Actin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
D016880	Anisotropy	A physical property showing different values in relation to the direction in or along which the measurement is made. The physical property may be with regard to thermal or electric conductivity or light refraction. In crystallography, it describes crystals whose index of refraction varies with the direction of the incident light. It is also called acolotropy and colotropy. The opposite of anisotropy is isotropy wherein the same values characterize the object when measured along axes in all directions.	Anisotropies
D018482	Muscle, Skeletal	A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.	Anterior Tibial Muscle,Gastrocnemius Muscle,Muscle, Voluntary,Plantaris Muscle,Skeletal Muscle,Soleus Muscle,Muscle, Anterior Tibial,Muscle, Gastrocnemius,Muscle, Plantaris,Muscle, Soleus,Muscles, Skeletal,Muscles, Voluntary,Skeletal Muscles,Tibial Muscle, Anterior,Voluntary Muscle,Voluntary Muscles