Fig. 2: Protein unfolding and refolding regulate the mechanical properties of composite fibers. | Nature Communications

Fig. 2: Protein unfolding and refolding regulate the mechanical properties of composite fibers.

From: Chain entanglement enhanced strong and tough wool keratin/albumin fibers for bioabsorbable and immunocompatible surgical sutures

Fig. 2

a Molecular dynamics (MD) simulations reveal that BSA and keratin undergo unfolding in the presence of urea and DTT, subsequently interacting with each other upon mixing. b SAXS analysis reveals Rg values of 5.6 nm and 3.8 nm for unfolded BSA and keratin, respectively. c Viscosity under an increasing shear rate of the protein composite solutions across varying protein ratios indicating a shear-thinning behavior. d The shear stress of the keratin spinning dope reveals that the non-Newtonian index gradually decreases as the proportion of BSA increases, indicating an enhancement in the entanglement within the spinning dope. e Representative stress-strain curves of the spun composite fibers at different protein ratios. f The breaking strength and toughness analysis of the spun composite fibers at different protein ratios. Data are presented as mean ± SD (5:0, n = 7; 4:1, n = 7; 3:2, n = 5; 2.5:2.5, n = 9; 0:5, n = 8). Statistical significance was analyzed by two-sample t-tests using OriginPro 2021 software. ns, no significant difference; ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; ∗∗∗∗p < 0.0001. g The secondary structure content of the spun composite fibers at different protein ratios is determined through deconvolution analysis of the amide I/II region on FTIR spectra. Source data are available in the Source Data file.

Back to article page