scholarly journals Detection of active site conformation changes of gamma-secretase, a key enzyme associated with Alzheimer disease, with small molecules

Author(s):  
Gertsik Natalya ◽  
Li Yue-Ming ◽  
Chau De-Ming
2012 ◽  
Vol 287 (21) ◽  
pp. 17288-17296 ◽  
Author(s):  
De-Ming Chau ◽  
Christina J. Crump ◽  
Jennifer C. Villa ◽  
David A. Scheinberg ◽  
Yue-Ming Li

Author(s):  
Kohei Sasamoto ◽  
Tomoki Himiyama ◽  
Kunihiko Moriyoshi ◽  
Takashi Ohmoto ◽  
Koichi Uegaki ◽  
...  

The acetylxylan esterases (AXEs) classified into carbohydrate esterase family 4 (CE4) are metalloenzymes that catalyze the deacetylation of acetylated carbohydrates. AXE from Caldanaerobacter subterraneus subsp. tengcongensis (TTE0866), which belongs to CE4, is composed of three parts: a signal sequence (residues 1–22), an N-terminal region (NTR; residues 23–135) and a catalytic domain (residues 136–324). TTE0866 catalyzes the deacetylation of highly substituted cellulose acetate and is expected to be useful for industrial applications in the reuse of resources. In this study, the crystal structure of TTE0866 (residues 23–324) was successfully determined. The crystal diffracted to 1.9 Å resolution and belonged to space group I212121. The catalytic domain (residues 136–321) exhibited a (β/α)7-barrel topology. However, electron density was not observed for the NTR (residues 23–135). The crystal packing revealed the presence of an intermolecular space without observable electron density, indicating that the NTR occupies this space without a defined conformation or was truncated during the crystallization process. Although the active-site conformation of TTE0866 was found to be highly similar to those of other CE4 enzymes, the orientation of its Trp264 side chain near the active site was clearly distinct. The unique orientation of the Trp264 side chain formed a different-shaped cavity within TTE0866, which may contribute to its reactivity towards highly substituted cellulose acetate.


2019 ◽  
Author(s):  
Edward A. Valera-Vera ◽  
Melisa Sayé ◽  
Chantal Reigada ◽  
Mariana R. Miranda ◽  
Claudio A. Pereira

AbstractEnolase is a glycolytic enzyme that catalyzes the interconversion between 2-phosphoglycerate and phosphoenolpyruvate. In trypanosomatids enolase was proposed as a key enzyme afterin silicoandin vivoanalysis and it was validated as a protein essential for the survival of the parasite. Therefore, enolase constitutes an interesting enzyme target for the identification of drugs against Chagas disease. In this work, a combined virtual screening strategy was implemented, employing similarity virtual screening, molecular docking and molecular dynamics. First, two known enolase inhibitors and the enzyme substrates were used as queries for the similarity screening on the Sweetlead database using five different algorithms. Compounds retrieved in the top 10 of at least three search algorithms were selected for further analysis, resulting in six compounds of medical use (etidronate, pamidronate, fosfomycin, acetohydroximate, triclofos, and aminohydroxybutyrate). Molecular docking simulations predicted acetohydroxamate and triclofos would not bind to the active site of the enzyme, and a re-scoring of the obtained poses signaled fosfomycin and aminohydroxybutyrate as bad enzyme binders. Docking poses obtained for etidronate, pamidronate, and PEP, were used for molecular dynamics calculations to describe their mode of binding. From the obtained results, we propose etidronate as a possibleTcENO inhibitor, and describe desirable and undesirable molecular motifs to be taken into account in the repurposing or design of drugs aiming this enzyme active site.


Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 153
Author(s):  
Xin Yin ◽  
Kaiwen Chen ◽  
Hao Cheng ◽  
Xing Chen ◽  
Shuai Feng ◽  
...  

The L-enantiomer of ascorbic acid is commonly known as vitamin C. It is an indispensable nutrient and plays a key role in retaining the physiological process of humans and animals. L-gulonolactone oxidase, the key enzyme for the de novo synthesis of ascorbic acid, is lacking in some mammals including humans. The functionality of ascorbic acid has prompted the development of foods fortified with this vitamin. As a natural antioxidant, it is expected to protect the sensory and nutritional characteristics of the food. It is thus important to know the degradation of ascorbic acid in the food matrix and its interaction with coexisting components. The biggest challenge in the utilization of ascorbic acid is maintaining its stability and improving its delivery to the active site. The review also includes the current strategies for stabilizing ascorbic acid and the commercial applications of ascorbic acid.


2004 ◽  
Vol 25 ◽  
pp. S556-S557
Author(s):  
Jun Wang ◽  
Dirk Beher ◽  
Mark S. Shearman ◽  
Alison Goate

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