Silk Reconstitution Disrupts Fibroin Self-Assembly.
Using atomic force microscopy, we present the first molecular-scale comparison of two of the most important silk dopes, native (NSF) and reconstituted (RSF) silkworm fibroin. We found that both systems depended on shear to show self-assembly. Significant differences in the nature of self-assembly between NSF and RSF were shown. In the highest studied concentration of 1000 mg/L, NSF exhibited assembly into 20-30 nm-wide nanofibrils closely resembling the surface structures found in natural silk fibers. RSF, in contrast, showed no self-assembly whatsoever at the same concentration, which suggests that the reconstitution process significantly disrupts silk's inherent self-assembly capability. At lower concentrations, both RSF and NSF formed fibrils under shear, apparently denatured by the substrate. Using image analysis, we quantified the properties of these self-assembled fibrils as a function of concentration and found low-concentration fibrils of NSF to form larger continuous structures than those of RSF, further supporting NSF's superior self-assembly capabilities.
The College of William & Mary , Department of Applied Science, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States.
Sean R
SR
Koebley
The College of William & Mary , Department of Applied Science, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States.
Daniel
D
Thorpe
The College of William & Mary , Department of Applied Science, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States.
Pei
P
Pang
The College of William & Mary , Department of Applied Science, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States.
Panos
P
Chrisochoides
Oxford Silk Group, Department of Zoology, Oxford University , Tinbergen Building, South Parks Road, Oxford, Oxfordshire OX1 3PS, United Kingdom.
Imke
I
Greving
Oxford Silk Group, Department of Zoology, Oxford University , Tinbergen Building, South Parks Road, Oxford, Oxfordshire OX1 3PS, United Kingdom.
Fritz
F
Vollrath
The College of William & Mary , Department of Applied Science, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States.
Hannes C
HC
Schniepp
D000818:Animals; D012831:Bombyx / Q000737:chemistry; D005349:Fibroins / Q000737:chemistry*; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000648:ultrastructure
D046912:Multiprotein Complexes; D005349:Fibroins