Fig. 3: Design and mechanical properties of btMfp5-fused 16xFGA variant fibers.

a Design of ^NMfp5(YtoS) sequence from ^NMfp5 with all tyrosine residues mutated to serine. Y and S mutated from Y were labeled in red, while K/R were labeled in blue. b Design of ^CMfp5(YtoS) and ^CMfp5(KRtoS) from ^CMfp5 with all tyrosine or lysine/arginine residues mutated to serine. Y and S mutated from Y were labeled in red, while K/R and S mutated from K/R were labeled in blue. c Schematics of mutations introduced to the split Mfp5 fragments. d Ultimate tensile strength of 16xFGA, 16xFGA-M, four btMfp5-fused 16xFGA variant fibers. e Toughness of 16xFGA, 16xFGA-M, four btMfp5-fused 16xFGA variant fibers. f Representative stress-strain curves of four btMfp5-fused 16xFGA variant fibers. g Summary of ultimate tensile stress for ^NM-16xFGA-^CM(YtoS) spun in different pH in 95% methanol; h summary of toughness for ^NM-16xFGA-^CM(YtoS) spun in different pH in 95% methanol; i representative stress-strain curves of ^NM-16xFGA-^CM(YtoS) spun in different pH in 95% methanol. Data are presented as mean values ± standard deviations. Error bars represent standard deviation. *p < 0.05, ****p < 0.0001, ordinary one-way ANOVA multiple comparisons. 16xFGA mechanical data reproduced from previous publication (reproduced with permission¹⁰, Copyright 2021 American Chemical Society) serve as a comparison. For all mechanical data other than ^NM(YtoS)−16xFGA-^CM fibers, n = 10 independent tensile test measurements; for ^NM(YtoS)−16xFGA-^CM fibers, n = 9 independent tensile test measurements. Details of source data and statistical analyses are provided in the Source Data file.