Modeling sickle hemoglobin fibers as one chain of coarse-grained particles

Li, He; Ha, Vi; Lykotrafitis, George

doi:10.1016/j.jbiomech.2012.05.016

Cited by 28 publications

(24 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Δ θ max defines the maximum deformation of the actin rings but its exact value does not affect the behavior of the system near equilibrium. The employed value of k b produces a bending rigidity of κ bend = 7.1 × 10 −26 Nm 2 for a straight stiff filament based on numerical calculations shown in S1 Text and in [37]. The obtained value is similar to the experimentally measured bending rigidity of actin filaments 7.3 × 10 −26 Nm 2 reported in [38, 39].…”

Section: Materials and Modelssupporting

confidence: 78%

“…The position of the center of each ring is calculated by utilizing the mean value of the z –coordinate of the actin particles. The choice of k mt is justified based on the following rationale: for small deformations, the FENE potential is approximated by , which corresponds to a harmonic potential with a spring constant k sp = k mt /Δ d max [37]. In this case, we can assume that τ = E L h , where τ is the stress, E L is the longitudinal Young’s modulus of the axon, and h is the strain.…”

Section: Materials and Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Modeling of the axon membrane skeleton structure and implications for its mechanical properties

Zhang

Abiraman

et al. 2017

PLoS Comput Biol

Self Cite

View full text Add to dashboard Cite

Super-resolution microscopy recently revealed that, unlike the soma and dendrites, the axon membrane skeleton is structured as a series of actin rings connected by spectrin filaments that are held under tension. Currently, the structure-function relationship of the axonal structure is unclear. Here, we used atomic force microscopy (AFM) to show that the stiffness of the axon plasma membrane is significantly higher than the stiffnesses of dendrites and somata. To examine whether the structure of the axon plasma membrane determines its overall stiffness, we introduced a coarse-grain molecular dynamics model of the axon membrane skeleton that reproduces the structure identified by super-resolution microscopy. Our proposed computational model accurately simulates the median value of the Young’s modulus of the axon plasma membrane determined by atomic force microscopy. It also predicts that because the spectrin filaments are under entropic tension, the thermal random motion of the voltage-gated sodium channels (Nav), which are bound to ankyrin particles, a critical axonal protein, is reduced compared to the thermal motion when spectrin filaments are held at equilibrium. Lastly, our model predicts that because spectrin filaments are under tension, any axonal injuries that lacerate spectrin filaments will likely lead to a permanent disruption of the membrane skeleton due to the inability of spectrin filaments to spontaneously form their initial under-tension configuration.

show abstract

Section: Materials and Modelssupporting

confidence: 78%

Section: Materials and Modelsmentioning

confidence: 99%

Modeling of the axon membrane skeleton structure and implications for its mechanical properties

Zhang

Abiraman

et al. 2017

PLoS Comput Biol

Self Cite

View full text Add to dashboard Cite

show abstract

“…They demonstrated that the molecular chirality is the main driver for the HbS polymer fiber formation. Li and Lykotrafitis simulated the biomechanical properties of HbS polymer fibers via two different coarse-grained HbS fiber models, demonstrating the significant role of fiber frustration and compression in fiber zipping and unzipping dynamics (Li and Lykotrafitis, 2011; Li et al, 2012a). To gain insight into the nature of the formation of HbS polymer fiber, in a recent study, Lu et al (2016a) developed a patchy particle HbS model to study the growth dynamics of HbS polymer fibers (Fig.…”

Section: Hemoglobin Propertiesmentioning

confidence: 99%

Biomechanics and biorheology of red blood cells in sickle cell anemia

Dao

Lykotrafitis

et al. 2017

Journal of Biomechanics

Self Cite

View full text Add to dashboard Cite

Sickle cell anemia (SCA) is an inherited blood disorder that causes painful crises due to vaso-occlusion of small blood vessels. The primary cause of the clinical phenotype of SCA is the intracellular polymerization of sickle hemoglobin resulting in sickling of red blood cells (RBCs) in deoxygenated conditions. In this review, we discuss the biomechanical and biorheological characteristics of sickle RBCs and sickle blood as well as their implications toward a better understanding of the pathophysiology and pathogenesis of SCA. Additionally, we highlight the adhesive heterogeneity of RBCs in SCA and their specific contribution to vaso-occlusive crisis.

show abstract

“…Chain chirality was confirmed to be the main driver for the formation of HbS fibers. Li and Lykotrafitis 48, 49 simulated the thermal behavior of HbS fibers and proposed that the continuous polymerization of HbS fibers and additional unzippering of these fibers can explain the formation of HbS fiber networks.…”

Section: Equilibrium Shapes and Fluctuationsmentioning

confidence: 99%