Effects of chemical modification, tropomyosin, and myosin subfragment 1 on the yield strength and critical concentration of F-actin
Biochemistry. 2002-05-01; 41(18): 5907-5912
DOI: 10.1021/bi0116745
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1. Biochemistry. 2002 May 7;41(18):5907-12.
Effects of chemical modification, tropomyosin, and myosin subfragment 1 on the
yield strength and critical concentration of F-actin.
Adami R(1), Cintio O, Trombetta G, Choquet D, Grazi E.
Author information:
(1)Dipartimento di Biochimica e Biologia Molecolare, Università di Ferrara, Via
Borsari 46, 44100 Ferrara, Italy.
The effects of coupling with tetramethylrhodamine-5-iodoacetamide and of the
decoration with tropomyosin and with myosin subfragment 1 on the elastic
properties of F-actin filament are investigated. At 22 degrees C, in 15 mM
orthophosphate and 3 mM MgCl2, tetramethylrhodamine F-actin displays a yield
strength of 3.69 +/- 0.213 pN and an elastic modulus by stretching of 0.91 MPa.
Decoration with tropomyosin increases the yield strength of tetramethylrhodamine
F-actin to 10.51 +/- 0.24 pN and the elastic modulus by stretching to 23-75 MPa.
Mixtures of myosin subfragment 1 and tetramethylrhodamine F-actin at the 0.2:1,
0.4:1, 0.6:1, 0.8:1, and 1:1 molar ratios are also studied. Both yield strength
and the elastic modulus by stretching are found to increase progressively with
the ratio. At the 1:1 molar ratio, the yield strength is 15.81 +/- 0.26 pN and
the elastic modulus by stretching is 13.45 to 40 MPa. Decoration of
tetramethylrhodamine F-actin with both tropomyosin and myosin subfragment 1, at
the 1:1 molar ratio with the actin monomer, produces filaments with an yield
strength of 22.3 +/- 0.48 pN.
DOI: 10.1021/bi0116745
PMID: 11980494 [Indexed for MEDLINE]