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.
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http://dx.doi.org/10.1021/acs.biomac.5b00732 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Fudan University, Department of Macromolecular Science, 2205 Songhu Rd, 200438, Shanghai, CHINA.
Nitrogen heterocyclic carbenes (NHCs) are emerging as effective substitutes for conventional thiol ligands in surface functionalization of nanoparticles (NPs), offering exceptional stability to NPs under harsh conditions. However, the highly reactive feature of NHCs limits their use in introducing chemically active groups onto the NP surface. Herein, we develop a general yet robust strategy for the efficient surface functionalization of NPs with copolymer ligands bearing various functional groups.
View Article and Find Full Text PDFChem Asian J
January 2025
IISER Bhopal Department of Chemistry, Chemistry, Indore By-pass Road, Bhauri, 462066, Bhopal, INDIA.
White-light generation using small organic molecules has gained significant attention from researchers working on the interface of supramolecular chemistry and organic materials. Self-assembled multi-chromophoric materials utilizing a drug molecule and microenvironment-sensitive intramolecular charge transfer dye as an emitter offer the possibility of tunable emission. In this investigation, we focused on white light generation via the combination of a polarity-sensitive red-emitting styryl chromone (SC) and a blue-emitting anticancer and psychotherapeutic drug Norharmane (NHM) in a self-assembled micellar system.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemistry, School of Science, Westlake University, Hangzhou, Zhejiang Province, China.
The self-assembly of small molecules through non-covalent interactions is an emerging and promising strategy for building dynamic, stable, and large-scale structures. One remaining challenge is making the non-covalent interactions occur in the ideal positions to generate strength comparable to that of covalent bonds. This work shows that small molecule YAWF can self-assemble into a liquid-crystal hydrogel (LCH), the mechanical properties of which could be controlled by water.
View Article and Find Full Text PDFBiochemistry (Mosc)
December 2024
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
Nuclear export protein (NEP) of the influenza A virus, being one of the key components of the virus life cycle, is a promising model for studying characteristics of formation of amyloids by viral proteins. Using atomic force microscopy, comparative study of aggregation properties of the recombinant NEP variants, including the protein of natural structure, as well as modified variants with N- and C-terminal affinity His-tags, was carried out. All protein variants under physiological conditions are capable of forming aggregates of various morphologies: micelle-like nanoparticles, flexible protofibrils, rigid amyloid fibrils, etc.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Qiqihar Medical University, Heilongjiang, Qiqihar 161006, China. Electronic address:
The clinical application of curcumin (CUR) is restricted by its low solubility, instability, and poor bioavailability. To overcome these limitations, we developed a novel stearic acid-grafted inulin-based nano-delivery system for CUR encapsulation. The structure of stearoyl inulin (SA-IN) was characterized using Fourier-transform infrared spectroscopy, hydrogen nuclear magnetic resonance, thermogravimetric analysis, and contact angle measurements.
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