scholarly journals Single-photon absorption of isolated collagen mimetic peptides and triple-helix models in the VUV-X energy range

2017 ◽  
Vol 19 (28) ◽  
pp. 18321-18329 ◽  
Author(s):  
Lucas Schwob ◽  
Mathieu Lalande ◽  
Jimmy Rangama ◽  
Dmitrii Egorov ◽  
Ronnie Hoekstra ◽  
...  

By monitoring ionization and fragmentation after single-photon absorption, we show that an isolated collagen triple helix model is stabilized by proline hydroxylation.

2021 ◽  
Vol 22 (9) ◽  
pp. 4533
Author(s):  
Tomoyuki Koga ◽  
Shinya Kingetsu ◽  
Nobuyuki Higashi

Self-assembly of artificial peptides has been widely studied for constructing nanostructured materials, with numerous potential applications in the nanobiotechnology field. Herein, we report the synthesis and hierarchical self-assembly of collagen-mimetic peptides (CMPs) bearing various aromatic groups at the N-termini, including 2-naphthyl, 1-naphtyl, anthracenyl, and pyrenyl groups, into nanofibers. The CMPs (R-(GPO)n: n > 4) formed a triple helix structure in water at 4 °C, as confirmed via CD analyses, and their conformations were more stable with increasing hydrophobicity of the terminal aromatic group and peptide chain length. The resulting pre-organized triple helical CMPs showed diverse self-assembly into highly ordered nanofibers, reflecting their slight differences in hydrophobic/hydrophilic balance and configuration of aromatic templates. TEM analysis demonstrated that 2Np-CMPn (n = 6 and 7) and Py-CMP6 provided well-developed natural collagen-like nanofibers and An-CMPn (n = 5–7) self-assembled into rod-like micelle fibers. On the other hand, 2Np-CMP5 and 1Np-CMP6 were unable to form nanofibers under the same conditions. Furthermore, the Py-CMP6 nanofiber was found to encapsulate a guest hydrophobic molecule, Nile red, and exhibited unique emission behavior based on the specific nanostructure. In addition to the ability of CMPs to bind small molecules, their controlled self-assembly enables their versatile utilization in drug delivery and wavelength-conversion nanomaterials.


2016 ◽  
Vol 858 ◽  
pp. 245-248 ◽  
Author(s):  
Hassan Hamad ◽  
Christophe Raynaud ◽  
Pascal Bevilacqua ◽  
Sigo Scharnholz ◽  
Bertrand Vergne ◽  
...  

Optical Beam Induced Current (OBIC) measurements are performed on 4H-SiC avalanche diodes with a very thin and a highly doped active region. A pulsed green laser, with a wavelength of 532 nm, illuminates a reverse biased diode leading to generate electron-hole pairs in the space charge region. Comparison between the 4H-SiC bandgap and the incident photon energy shows that single photon absorption process can be neglected and two-photon absorption process dominates in this case. Ionization rates are then extracted from multiplication curve in a high electric field range (3 to 5 MV.cm–1). Results are in good agreement with previous ones obtained on the same diodes using single photon absorption process.


1979 ◽  
Vol 70 (7) ◽  
pp. 3291-3299 ◽  
Author(s):  
Edward Catalano ◽  
Robert E. Barlettab) ◽  
Richard K. Pearson

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