scholarly journals The Effect of Optical Isomer for Amino-acid Interaction Potential

2020 ◽  
Vol 19 (4) ◽  
pp. 149-150
Author(s):  
Chieko TERASHIMA ◽  
Yoshiaki TANIDA ◽  
Hiroyuki SATO
1983 ◽  
Vol 38 (5-6) ◽  
pp. 359-368 ◽  
Author(s):  
Fritz Thümmler ◽  
Wolfhart Rüdiger ◽  
Edmund Cmiel ◽  
Siegfried Schneider

Chromopeptides were prepared by pepsin digestion of C-phycocyanin isolated from the cyano­bacterium Spirulina maxima and of phytochrome isolated from seedlings of Avena sativa L. The chromopeptides were characterized by amino acid analysis. The ZZZ configurated chromophore of the phycocyanin peptide was transformed into its ZZE configurated isomer by the method of Falk et al. (Mh. Chemie 111, 159- 175, 1980) which had previously been applied to biliverdins. The 500 MHz 1HNMR spectrum of the ZZE configurated chromopeptides confirmed that its chromophore has the 15 E configuration. Irradiation yielded the ZZZ configurated isomer for which the 1H NMR spectrum was also recorded. Native phytochrome was irradiated at 660 nm to yield the maximum amount of the Pfr from (about 75% of total phytochrome). By digestion in the dark the previously described Pfr chromopeptide was obtained. The 500 MHz 1H NMR spectrum was compared with that of the ZZE phycocyanin peptide. It confirmed the 15 E con­figuration of the Pfr chromopeptide. Irradiation yielded the 15 Z configurated Pr chromopeptide. Comparison of the high resolution 1HNMR spectra of Pfr and Pr chromopeptides revealed that not only the chromophore resonances but also those of some amino acids are changed by the Pfr → Pr chromopeptide phototransformation. The results are discussed in terms of chromophore amino acid interaction.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Omar Gaci

We represent proteins by amino acid interaction networks. This is a graph whose vertices are the proteins amino acids and whose edges are the interactions between them. Once we have compared this type of graphs to the general model of scale-free networks, we analyze the existence of nodes which highly interact, the hubs. We describe these nodes taking into account their position in the primary structure to study their apparition frequency in the folded proteins. Finally, we observe that their interaction level is a consequence of the general rules which govern the folding process.


2010 ◽  
Vol 19 (3) ◽  
pp. 603-616 ◽  
Author(s):  
Anupam Nath Jha ◽  
Saraswathi Vishveshwara ◽  
Jayanth R. Banavar

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