scholarly journals The role of DNA nanostructures in the catalytic properties of an allosterically regulated protease

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard Kosinski ◽  
Joel Mieres Perez ◽  
Elisa-C. Schöneweiß ◽  
Yasser B. Ruiz-Blanco ◽  
Irene Ponzo ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Dna Nanostructures

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

scholarly journals Enhancement of aromatase activity by D-aspartic acid in the ovary of the lizard Podarcis s. sicula

Reproduction ◽  
2001 ◽  
pp. 803-808 ◽  
Author(s):  
L Assisi ◽  
V Botte ◽  
A D'Aniello ◽  
MM Di Fiore
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Reproductive Cycle ◽  
Catalytic Properties ◽  
Ovarian Tissue ◽  
Experimental Treatment ◽  
Tissue Homogenate ◽  
Aromatase Activity

The present study investigated the role of D-aspartic acid (D-Asp) in ovarian steroidogenesis and its effect on aromatase activity in the lizard, Podarcis s. sicula. It was determined that D-Asp concentrations vary significantly during phases of the reproductive cycle: they vary inversely with testosterone concentrations and directly with oestradiol concentrations in the ovary and plasma. Experimental treatment showed that administration of D-Asp induces a decrease in testosterone and an increase in oestradiol, and that treatment with other amino acids (L-Asp, D-Glu and D-Ala) instead of D-Asp has no effects. Experiments in vitro confirmed these results. Furthermore, these experiments showed an increase in aromatase activity, as the addition of D-Asp either to fresh ovarian tissue homogenate or to acetonic powder of ovarian follicles induced a significant increase in the conversion of testosterone to oestradiol. Aromatase activity is four times greater in the presence of D-Asp than in its absence. However, almost equivalent values of the two K(m) values (both approximately 25 nmol l(-1)) indicate that aromatase has the same catalytic properties in both cases.

scholarly journals Role of Dimerization in the Catalytic Properties of the Escherichia coli Disulfide Isomerase DsbC

2009 ◽  
Vol 284 (36) ◽  
pp. 23972-23979 ◽  
Author(s):  
Silvia A. Arredondo ◽  
Tiffany F. Chen ◽  
Austen F. Riggs ◽  
Hiram F. Gilbert ◽  
George Georgiou
Keyword(s):  
Escherichia Coli ◽  
Catalytic Properties ◽  
Disulfide Isomerase

Catalytic Properties and the Role of Copper in Bovine and Lentil Seedling Copper/Quinone-Containing Amine Oxidases: Controversial Opinions

2005 ◽  
Vol 2005 (9) ◽  
pp. 1635-1641 ◽  
Author(s):  
Enzo Agostinelli ◽  
Francesca Belli ◽  
Laura Dalla Vedova ◽  
Silvia Longu ◽  
Anna Mura ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Amine Oxidases ◽  
Lentil Seedling

scholarly journals Influence of Magnesium Ions on the Preparation and Storage of DNA Tetrahedrons in Micromolar Ranges

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2091 ◽  
Author(s):  
Yue Hu ◽  
Zhou Chen ◽  
Zheng Hou ◽  
Mingkai Li ◽  
Bo Ma ◽  
...  
Keyword(s):  
The Novel ◽  
Magnesium Ions ◽  
Dna Nanostructures ◽  
Structure And Stability ◽  
Dna Concentration ◽  
Factors Influencing ◽  
Dna Tetrahedron ◽  
And Storage

The DNA tetrahedron (Td), as one of the novel DNA-based nanoscale biomaterials, has been extensively studied because of its excellent biocompatibility and increased possibilities for decorating precisely. Although the use of Td in laboratories is well established, knowledge surrounding the factors influencing its preparation and storage is lacking. In this research, we investigated the role of the magnesium ions, which greatly affect the structure and stability of DNA. We assembled 1, 2, 5, 10 and 20 μM Td in buffers containing different Mg2+ concentrations, demonstrating that 2 and 5 mM Mg2+ is optimal in these conditions, and that yields decrease dramatically once the DNA concentration reaches 20 μM or the Mg2+ concentration is lower than 0.5 mM. We also verified that the Td structure is retained better through freeze-thawing than lyophilization. Furthermore, a lower initial Mg2+ (≤2 mM) benefited the maintenance of Td structure in the process of lyophilization. Hence, our research sheds light on the influence of Mg2+ in the process of preparing and storing Td, and also provides some enlightenment on improving yields of other DNA nanostructures.

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