Enzyme Hyperactivation System Based on a Complementary Charged Pair of Polyelectrolytes and Substrates

Langmuir ◽  
2014 ◽  
Vol 30 (13) ◽  
pp. 3826-3831 ◽  
Author(s):  
Takaaki Kurinomaru ◽  
Shunsuke Tomita ◽  
Yoshihisa Hagihara ◽  
Kentaro Shiraki
Keyword(s):  
Charged Pair

scholarly journals Charged Pair Current Networks in Bioenergetics

1974 ◽  
Vol 71 (8) ◽  
pp. 3064-3067 ◽  
Author(s):  
G. Kemeny
Keyword(s):  
Charged Pair

Induction of Secondary Structure through Micellization of an Oppositely Charged Pair of Homochiral Block- and Homopolypeptides in an Aqueous Medium

2015 ◽  
Vol 36 (22) ◽  
pp. 1958-1964 ◽  
Author(s):  
Omer F. Mutaf ◽  
Akihiro Kishimura ◽  
Yuki Mochida ◽  
Ahram Kim ◽  
Kazunori Kataoka
Keyword(s):  
Secondary Structure ◽  
Aqueous Medium ◽  
Charged Pair ◽  
Oppositely Charged

The approximately normal model for charged pair production: A reconsideration

1973 ◽  
Vol 58 (2) ◽  
pp. 541-556 ◽  
Author(s):  
G.D. Kaiser
Keyword(s):  
Pair Production ◽  
Normal Model ◽  
Charged Pair

Staggered molecular packing in crystals of a collagen-like peptide with a single charged pair

2000 ◽  
Vol 301 (5) ◽  
pp. 1191-1205 ◽  
Author(s):  
Rachel Z Kramer ◽  
Manju G Venugopal ◽  
Jordi Bella ◽  
Patricia Mayville ◽  
Barbara Brodsky ◽  
...  
Keyword(s):  
Molecular Packing ◽  
Charged Pair

scholarly journals Insights into steroidogenic acute regulatory protein (StAR)-dependent cholesterol transfer in mitochondria: evidence from molecular modeling and structure-based thermodynamics supporting the existence of partially unfolded states of StAR

2002 ◽  
Vol 29 (3) ◽  
pp. 327-345 ◽  
Author(s):  
AP Mathieu ◽  
A Fleury ◽  
L Ducharme ◽  
P Lavigne ◽  
JG LeHoux
Keyword(s):  
Molecular Structure ◽  
Binding Site ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Star Activity ◽  
Charged Pair ◽  
Steroidogenic Acute Regulatory ◽  
Partially Unfolded ◽  
Partially Unfolded States ◽  
Cholesterol Binding

The steroidogenic acute regulatory protein (StAR) is the major entrance for cholesterol in mitochondria under acute stimulation. Under such circumstances, dysfunctional StAR activity can ultimately lead to lipoid congenital adrenal hyperplasia (LCAH). A complete understanding of the StAR's molecular structure and mechanism is essential to comprehend LCAH. Thus far, there is no mechanistic model that can explain experimental results at the molecular level. This is partly due to the lack of the molecular structure of StAR. The closest approximation to the StAR molecular structure is the human MLN64 which has a similar activity to StAR, has a highly homologous primary structure and for which an X-ray structure is known. In this context, we have modeled the structure of StAR through standard homology modeling procedures based on the MLN64 structure. Our StAR model shows the presence of a hydrophobic cavity of 783.9 A(2) in surface area, large enough to fit one molecule of cholesterol. In addition, we have identified a unique charged pair, as in MLN64, lining the surface of the cavity and which could play a key role in the binding of cholesterol through the formation of an H-bond with its OH moiety. This suggests that the cholesterol-binding site of StAR is located inside this cavity. Taking into account that internal cavities are destabilizing to native protein structures and that the lining of the cavity has to become accessible in order to allow cholesterol binding, we have explored the possibility that StAR could exist in equilibrium with partially unfolded states. Using a structure-based thermodynamics approach, we show that partially folded states (with an unfolded C-terminal alpha-helix, and an open cavity) can be significantly populated at equilibrium and therefore allow cholesterol binding. These results are supported by recent experiments that show a loss of StAR helical character upon binding of an analog of cholesterol. Moreover, we show that the replacement of the residues involved in the charged-pair located in the binding site results in the loss of StAR activity, supporting a key role for these residues. Taken together, our results are applicable to StAR functioning both in the mitochondrial intermembrane space as well as outside the mitochondria.

scholarly journals The NV−....N+ charged pair in Diamond: a Quantum-Mechanical investigation

2021 ◽  
Author(s):  
Anna Maria Ferrari ◽  
Khaled E. El-Kelany ◽  
Francesco Silvio Gentile ◽  
Maddalena D'Amore ◽  
Roberto Dovesi
Keyword(s):  
Basis Set ◽  
Quantum Mechanical ◽  
Gaussian Type ◽  
B3lyp Functional ◽  
Mechanical Investigation ◽  
Crystal Code ◽  
Charged Pair

The NV−....N+ charged pair in diamond has been investigated by using a Gaussian-type basis set, the B3LYP functional, the supercell scheme and the CRYSTAL code. It turns out that: i)...

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