The Role of Pro20 in the Isomerization of MyotoxinafromCrotalus viridis viridis:Folding and Structural Characterization of Synthetic Myotoxinaand Its Pro20Gly Homolog

1997 ◽  
Vol 241 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Dobrin Nedelkov ◽  
Michael P. O'keefe ◽  
Tara L. Chapman ◽  
Allan L. Bieber
2011 ◽  
Vol 39 (12) ◽  
pp. 2411-2420 ◽  
Author(s):  
Vanina Rea ◽  
Sanja Dragovic ◽  
Jan Simon Boerma ◽  
Frans J. J. de Kanter ◽  
Nico P. E. Vermeulen ◽  
...  

2001 ◽  
Vol 74 (3) ◽  
pp. 355-375 ◽  
Author(s):  
Yasuyuki Tanaka

Abstract Structural characterization of naturally occurring polyisoprenes was carried out to solve the mystery of natural rubber (NR), such as the biosynthesis mechanism of rubber formation, the origin of outstanding properties of NR and the role of rubber in rubber trees. The NMR analysis, based on terpenes and polyprenols as models, disclosed the structure of both terminal groups of rubber chain. Structural evidence indicated that the biosynthesis of rubbers from Lactarius mushroom and leaves of high plants starts from trans, trans-farnesyl diphosphate or trans, trans, trans-geranylgeranyl diphosphate and terminates by dephosphorylation to form a hydroxyl terminal group. The biosynthesis of NR was presumed to start from unidentified initiating species containing two trans-isoprene units and peptide group and to terminate forming a phospholipid terminal group. The initiating group of NR associated with proteins formed branch points, which can be decomposed by enzymatic deproteinization. The branch points formed by phospholipid group were decomposed by transesterification with sodium methoxide. Rapid crystallization of NR was explained by the presence of mixed fatty acids synergistically with linked fatty acids, which were included in phospholipid. Saturated fatty acids linked to rubber chain induced crystallization, while mixed unsaturated fatty acids acted as plasticizer and accelerated the crystallization rate. This was confirmed by the preparation of model cis-polyisoprene grafted with stearic acid. The green strength of NR decreased to the same level as synthetic cis-polyisoprene after transesterification, indicating the effect of branching formed by the phospholipid terminal group and fatty acids in NR. The role of NR in Hevea trees was analyzed using NR from Hevea trees never tapped before. The formation of hard gel and oxidative degradation during the storage of NR in Hevea trees suggested that NR acted as a radical scavenger to remove hydroperoxide.


2021 ◽  
Vol 22 (2) ◽  
pp. 260-268
Author(s):  
V. Dzhagan ◽  
O. Kapush ◽  
S. Budzulyak ◽  
N. Mazur ◽  
E. Gavryliuk ◽  
...  

Cu2ZnSnS4 (CZTS) is one of the promising materials for absorber layers of new-generation thin film solar cells. Various synthetic routes of materials preparation and structural characterization have been explored so far. Further tuning of the CZTS properties is realized via partial substitution of the cations. Here we have used an affordable and scalable method of synthesizing colloidal CZTS nanocrystals (NC) in an aqueous solution. Variation of the synthesis parameters, in particular pH of the solution, was employed to improve the crystallinity of the NCs. Furthermore, CZTS NCs with partial substitution of Cu for Ag were also successfully synthesized. Raman spectroscopy was employed as a prime tool of structural characterization of the NCs obtained, along with optical absorption spectroscopy and ab initio DFT lattice dynamics calculations. An experimentally observed slight upward shift of the main phonon Raman peak upon increase of the Ag content in (AgxCu1-x)2ZnSnS4 NCs is in agreement with the trend predicted by DFT calculation. No pure Ag2ZnSnS4 NCs could be formed, indicating a critical role of Cu in forming the kesterite structure NCs under given synthesis conditions in an aqueous medium.


2010 ◽  
Vol 46 (4) ◽  
pp. 910-922 ◽  
Author(s):  
G. Salviulo ◽  
M. Bettinelli ◽  
U. Russo ◽  
A. Speghini ◽  
L. Nodari

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kaneez Fatima ◽  
Esam Azhar ◽  
Shilu Mathew ◽  
Ghazi Damanhouri ◽  
Ishtiaq Qadri

This study described the structural characterization of Pakistani HCV NS3 GT3a in parallel with genotypes 1a and 1b NS3. We investigated the role of amino acids and their interaction patterns in different HCV genotypes by crystallographic modeling. Different softwares were used to study the interaction pattern, for example, CLCBIO sequence viewer, MODELLER, NMRCLUST, ERRAT score, and MODELLER. Sixty models were produced and clustered into groups and the best model of PK-NCVI/Pk3a NS3 was selected and studied further to check the variability with other HCV NS3 genotypes. This study will help in future to understand the structural architecture of HCV genome variability and to further define the conserved targets for antiviral agents.


Metallomics ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 613-621 ◽  
Author(s):  
H. Lebrette ◽  
E. Borezée-Durant ◽  
L. Martin ◽  
P. Richaud ◽  
E. Boeri Erba ◽  
...  

Staphylococcus aureuspossesses two canonical ABC-importers dedicated to nickel acquisition: the NikABCDE and the CntABCDF systems, active under different growth conditions.


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