Backbone elasticity of ssDNA

Range 800 to 1,000 pN
Organism Bacteria Escherichia coli
Reference Vanzi F, Takagi Y, Shuman H, Cooperman BS, Goldman YE. Mechanical studies of single ribosome/mRNA complexes. Biophys J. 2005 Sep89(3):1909-19. p.1914 right column 2nd paragraphPubMed ID15951374
Primary Source Smith SB, Cui Y, Bustamante C. Overstretching B-DNA: the elastic response of individual double-stranded and single-stranded DNA molecules. Science. 1996 Feb 9 271(5250):795-9.PubMed ID8628994
Method [primary source abstract:] "Single molecules of double-stranded DNA (dsDNA) were stretched with force-measuring laser tweezers"
Comments "The estimated stretch modulus (K) was 870±140 pN (mean±SE,n=24), in good agreement with the values of 800–1000 pN reported for ssDNA (primary source)". See Wang et al., 1997 PMID 9138579 p.1345 left column 2nd paragraph: "Recently Bustamante and colleagues (primary source) estimated the elastic modulus from their single-molecule data by making a single-point extrapolation based on the high-force behavior of the force-extension curve, reporting a value of 1087 pN (at high ionic strength, in a buffer containing both mono- and divalent ions). This number compares closely to several estimates of the modulus obtained here by direct fits to either the high-force regime alone, using the Odijk formula, or over the complete force range, using the modified Marko-Siggia formula. [Investigators] anticipate that single-molecule optical techniques similar to those presented here, in conjunction with appropriate theory, will be broadly applicable to the rapid and accurate determination of micromechanical properties for a variety of biopolymers."
Entered by Uri M
ID 109076