Micromechanics of isolated sickle cell hemoglobin fibers: bending moduli and persistence lengths 1 1Edited by I. Tinoco

Wang, Jiang Cheng; Turner, Matthew S.; Agarwal, Gunjan; Kwong, Suzanna; Josephs, Robert; Ferrone, Frank A.; Briehl, Robin W.

doi:10.1006/jmbi.2001.5130

Cited by 67 publications

(101 citation statements)

References 31 publications

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“…For fibrils that reach equilibrium in two dimensions on the surface before being adsorbed (Fig. 3A), the mean square midpoint f luctuations from a secant joining two points of the polymer are given by (40):…”

Section: Methodsmentioning

confidence: 99%

Characterization of the nanoscale properties of individual amyloid fibrils

Smith

Knowles

Dobson

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

591

575

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We report the detailed mechanical characterization of individual amyloid fibrils by atomic force microscopy and spectroscopy. These self-assembling materials, formed here from the protein insulin, were shown to have a strength of 0.6 ؎ 0.4 GPa, comparable to that of steel (0.6 -1.8 GPa), and a mechanical stiffness, as measured by Young's modulus, of 3.3 ؎ 0.4 GPa, comparable to that of silk (1-10 GPa). The values of these parameters reveal that the fibrils possess properties that make these structures highly attractive for future technological applications. In addition, analysis of the solutionstate growth kinetics indicated a breakage rate constant of 1.7 ؎ 1.3 ؋ 10 ؊8 s ؊1 , which reveals that a fibril 10 m in length breaks spontaneously on average every 47 min, suggesting that internal fracturing is likely to be of fundamental importance in the proliferation of amyloid fibrils and therefore for understanding the progression of their associated pathogenic disorders.atomic force microscopy ͉ force spectroscopy ͉ nanotechnology ͉ prions ͉ protein aggregation

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Section: Methodsmentioning

confidence: 99%

Characterization of the nanoscale properties of individual amyloid fibrils

Smith

Knowles

Dobson

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

591

575

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“…This type of stiffness measurement, which is based on the monitoring of the rod-shape deformations caused by the thermal forces, was initially performed on biological polymers (7) and biological filaments of the cytoskeleton including actin (8)(9)(10), microtubules (9,(11)(12)(13), intermediate (14), and other filaments (15)(16)(17). It allowed in vivo measurements (13), although most studies were performed in vitro, in various boundary conditions (14).…”

mentioning

confidence: 99%

“…However, this technique rapidly reaches its limit for stiff rods because the mode amplitude decays like n −2 (n being the mode number) and higher modes become quickly indistinguishable from the noise of the detection system (SI Text, Eigenmode Analysis of the Rod Fluctuations). To circumvent this difficulty, the bending modulus of very rigid objects such as carbon nanotubes (18) or hemoglobin fibers (15) was derived from the fluctuations at a single rod location (tip or middle point), whose variance in real space was estimated from a summation over all modes. Later, Benetatos and Frey (28) renewed the theory by establishing the analogy between the WLC model and the quantum mechanics description of a rigid rotator.…”

mentioning

confidence: 99%

Optical detection of nanometric thermal fluctuations to measure the stiffness of rigid superparamagnetic microrods

Gerbal

Wang

2017

Proc. Natl. Acad. Sci. U.S.A.

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The rigidity of numerous biological filaments and crafted microrods has been conveniently deduced from the analysis of their thermal fluctuations. However, the difficulty of measuring nanometric displacements with an optical microscope has so far limited such studies to sufficiently flexible rods, of which the persistence length ( (1), the method that consists of measuring the dispersion of a thermostated system to assess its properties has brought a plethora of scientific successes. For instance, the tracking of Brownian or more complex diffusive particles immersed in a fluid opened up a new era in microrheology (2, 3). The calibration of numerous microtools such as optical tweezers (4), glass fibers (5), or atomic force microscope (AFM) cantilevers (6) also relies on the assessment of thermal motions. The principle of the method was also adapted to measure the intrinsic mechanical properties of nano-and microrods.This type of stiffness measurement, which is based on the monitoring of the rod-shape deformations caused by the thermal forces, was initially performed on biological polymers (7) and biological filaments of the cytoskeleton including actin (8-10), microtubules (9, 11-13), intermediate (14), and other filaments (15-17). It allowed in vivo measurements (13), although most studies were performed in vitro, in various boundary conditions (14). The method is also used in nanosciences, essentially to probe carbon nanotubes (18-20) that, despite their extremely large elastic modulus, have a sufficiently small radius to exhibit detectable fluctuations. Numerous other methods exist to measure the rod stiffness: Nanoindentation (21), AFM measurements (21, 22), and other techniques based on an external solicitation (21, 23) are commonly performed. However, they require relatively complex equipment. In contrast, the thermal method is neither invasive nor disruptive: It consists of acquiring a set of pictures of the rod, an observation that most often can be performed with an optical microscope only. For this purpose, superresolutive techniques have recently emerged and currently allow the optical observation of nanometric fluctuations, beyond the optical diffraction limit (24,25).If it is possible to take the anisotropic internal structure (such as the spontaneous curvature) of the rods into account (26), most analyses rely on the simple isotropic worm-like chain (WLC) model (27): For more than a decade, according to this model, the persistence length Lp = C k B T (where C is the bending modulus and kB T the thermal energy) was deduced from the experimental data after a decomposition of the filament shape in bending eigenmodes (Fig. S1), each of them being an independent probe of the filament flexural properties (10, 11, 13). However, this technique rapidly reaches its limit for stiff rods because the mode amplitude decays like n −2 (n being the mode number) and higher modes become quickly indistinguishable from the noise of the detection system (SI Text, Eigenmode Analysis of the Rod Fluctuations). To circumvent...

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“…Drasler et al [12] suggest that the presence of both the cell membrane and the internal HbS is a major factor in determining the viscoelastic behavior of sickle cells during deoxygenation. Pathogenesis in SCD arises from the deoxygenation dependant polymerization of sickle cell hemoglobin (HbS) into long, stiff, rod-like fibres [13]. Maciaszek and Lykotrafitis [5] employed AFM to measure the stiffness of abnormal human RBCs from human subjects with the genotype for skill cell trait, and they conclude that the young's modulus of pathological erythrocytes approximately three times higher than in normal cells.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Mechanical Behavior of Red Cell Membrane in Sickle Cell Disease

Fisseha¹,

Katiyar²

2012

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Sickle cell disease (SCD) is a disease of abnormal rheology. The rheological properties of normal erythrocytes appear to be largely determined by those of the red cell membrane. In SCD, the intracellular polymerization of sickle hemoglobin upon deoxygnation leads to marked increase in intracellular viscosity and elastic stiffness and also having indirect effects on cell membrane .To examine mathematically, the abnormal cell rheology behavior due to polymerization process and that due membrane abnormalities , we mechanically modeled the whole cell deformability as viscoelastic solid and proposed a Voigt-model of nonlinear viscoelastic solid constitutive relation as " mixture''of an elastic and viscous dissipative parts, with parameters of elastic and viscous moduli. The elastic part used to express stress-strain relations via strain energy function of the material and the viscous part derivation depends on strain -rate of deformation. The combination of both constitutive expressions is used to predict the viscoelastic properties of normal and sickle erythrocyte. Furthermore, sickle hemoglobin polymerization also leads to alter the osmotic behavior of the cell and to investigate such osmotic effect; we employ the van't Hoff law of osmotic pressure versus volume relation. The analysis of both formulations presented well the abnormal rheological /mechanical characterization of sickle erythrocyte membrane as we understood and concluded from our results.

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Micromechanics of isolated sickle cell hemoglobin fibers: bending moduli and persistence lengths 1 1Edited by I. Tinoco

Cited by 67 publications

References 31 publications

Characterization of the nanoscale properties of individual amyloid fibrils

Characterization of the nanoscale properties of individual amyloid fibrils

Optical detection of nanometric thermal fluctuations to measure the stiffness of rigid superparamagnetic microrods

Analysis of Mechanical Behavior of Red Cell Membrane in Sickle Cell Disease

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