scholarly journals Biomimetic gyroid nanostructures exceeding their natural origins

2016 ◽  
Vol 2 (5) ◽  
pp. e1600084 ◽  
Author(s):  
Zongsong Gan ◽  
Mark D. Turner ◽  
Min Gu

Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterflyCallophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young’s modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings ofC. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures.

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1465-1468 ◽  
Author(s):  
Steven Daly ◽  
Frédéric Rosu ◽  
Valérie Gabelica

DNA and proteins are chiral: Their three-dimensional structures cannot be superimposed with their mirror images. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We studied guanine-rich strands having various secondary structures, electrosprayed them as negative ions, irradiated them with an ultraviolet nanosecond optical parametric oscillator laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resembled those of their solution-phase counterparts, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.


D uring ribonuclease S (RN ase S) refolding, two peptide fragm ents recognize each other, and bind to g eth er to form a refolding in term ediate which slowly converts to th e nativ e state. We have characterized this refolding interm ediate using absorbance, circular dichroism (CD), and nuclear m agnetic resonance (NMR) spectroscopies. These techniques reveal significant am ounts of bo th secondary and te rtia ry stru ctu re ; the in term ediate differs from a m olten globule in being packed and native-like, b u t it resembles a m olten globule in having no near-ultraviolet (UV) CD spectrum . Final refolding is slow and accom panies proline isom erization. The results show th a t a t least two separate stages are observed in the form ation of the te rtia ry stru ctu re of RNaseS.


2014 ◽  
Vol 253 (3) ◽  
pp. 183-190 ◽  
Author(s):  
G.-Y. ZHUO ◽  
H. LEE ◽  
K.-J. HSU ◽  
M.J. HUTTUNEN ◽  
M. KAURANEN ◽  
...  

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