127,363 results match your criteria crystal structure

Study on structural characterization, physicochemical properties and digestive properties of euryale ferox resistant starch.

Food Chem 2021 Apr 22;359:129924. Epub 2021 Apr 22.

School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China.

At present, the raw materials for industrialized RS3 products are relatively simple and its purity is low. In addition, the correlation between structure and digestion characteristics of RS3 are rarely studied. In this study, euryale ferox, a kind of annual aquatic herb crop with high content of starch was used as a raw material to prepare RS3 by different methods, including autoclaving, enzymolysis-autoclaving and dual enzymolysis, respectively. Read More

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Stigmasterol isolated from the chloroform fraction of Benth fruit induces mitochondrial-dependent apoptosis in rat liver.

J Complement Integr Med 2021 May 10. Epub 2021 May 10.

Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, University of Ibadan, Ibadan, Nigeria.

Objectives: Decoction of fruit is used in folkloric medicine for treating dysmenorrhea and gonorrhea. Phytochemicals from may be potent in inducing mitochondrial-dependent apoptosis via the opening of the mitochondrial permeability transition (MPT) pore. Therefore, this study investigated the effects of stigmasterol isolated from the chloroform fraction of (CFAB) and also the increasing concentration of CFAB on the opening of rat liver mitochondrial permeability transition (MPT) pore. Read More

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A structural intermediate pre-organizes the add adenine riboswitch for ligand recognition.

Nucleic Acids Res 2021 May 8. Epub 2021 May 8.

Department of Biology, Faculty of Science, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada.

Riboswitches are RNA sequences that regulate gene expression by undergoing structural changes upon the specific binding of cellular metabolites. Crystal structures of purine-sensing riboswitches have revealed an intricate network of interactions surrounding the ligand in the bound complex. The mechanistic details about how the aptamer folding pathway is involved in the formation of the metabolite binding site have been previously shown to be highly important for the riboswitch regulatory activity. Read More

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Permeability of anodic alumina membranes grown on low-index aluminium surfaces.

Nanotechnology 2021 May 7. Epub 2021 May 7.

Lomonosov Moscow State University, Moscow, RUSSIAN FEDERATION.

Porous anodic aluminium oxide (AAO) membranes have various practical applications in separation and purification technologies. Numerous approaches have been utilized to tailor the transport properties of porous AAO films, but all of them assumed the isotropic nature of anodized aluminium. Here, the impact of aluminium crystallography on the permeability of AAO membranes is disclosed. Read More

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Diterpenoids from the seeds of Euphorbia lathyris and their anti-inflammatory activity.

Bioorg Chem 2021 Apr 26;112:104944. Epub 2021 Apr 26.

Wuya College of Innovation, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, China. Electronic address:

Twelve previously undescribed diterpenoids, euplarisans A-L (1-12), including one premyrsinane and eleven lathyranes, along with ten known analogues 13-22 were isolated from the seeds of Euphorbia lathyris. Their chemical structures were delineated by spectroscopic analysis and single-crystal X-ray diffraction. Interestingly, both 5 and 6 possessed an unusual trans-gem-dimethylcyclopropane as structural features and compound 8 was elucidated as premyrsinane-type diterpenoid. Read More

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Disordered Photonic Time Crystals.

Phys Rev Lett 2021 Apr;126(16):163902

Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.

We study the propagation of electromagnetic waves in disordered photonic time crystals: spatially homogenous media whose refractive index changes randomly in time. We find that the group velocity of a pulse propagating in such media decreases exponentially, eventually coming to a complete stop, while experiencing exponential growth in intensity. These effects greatly depend on the Floquet band structure of the photonic time crystal, with the strongest sensitivity to disorder occurring in superluminal modes. Read More

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Insights into the Structures and Bonding of Medium-Sized Cerium-Doped Boron Clusters.

J Phys Chem A 2021 May 7. Epub 2021 May 7.

School of Mathematics and Physics, China University of Geosciences (Wuhan), Wuhan 430074, China.

Since the discovery of metal-doped boron clusters attracted great significance to create a new class of materials, research interests have been directed to chemical bonding and structural evolution of lanthanide boride clusters. Here, we perform an extensive ground-state structure search for the CeB and CeB clusters in the size range from 9 to 18 using the Crystal structure AnaLYsis by Particle Swarm Optimization method and density functional theory optimization. It is found that the ground-state structures in both neutral and anionic series possess half-sandwich geometry. Read More

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A pH Switch Controls Zinc Binding in Tomato Copper-Zinc Superoxide Dismutase.

Biochemistry 2021 May 7. Epub 2021 May 7.

Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States.

Copper-zinc superoxide dismutase (SOD1) is a major antioxidant metalloenzyme that protects cells from oxidative damage by superoxide anions (O). Structural, biophysical, and other characteristics have in the past been compiled for mammalian SOD1s and for the highly homologous fungal and bovine SOD1s. Here, we characterize the biophysical properties of a plant SOD1 from tomato chloroplasts and present several of its crystal structures. Read More

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Multimetal lanthanide phosphonocarboxylate frameworks: structures, colour tuning and near-infrared emission.

Dalton Trans 2021 May 7. Epub 2021 May 7.

Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200438, China.

A series of isostructural lanthanide phosphonocarboxylate frameworks {(H3O)3[Ln7(pbpdc)6(DMF)4(H2O)3]·4H2O}n (named LnPCF, Ln = Tb, Eu and Gd, H4pbpdc = 4'-phosphono-[1,1'-biphenyl]-3,5-dicarboxylic acid) were solvothermally synthesized and characterized by the single crystal X-ray diffraction technique. By combining lanthanide cations with a phosphonocarboxylate ligand, a heptametallic lanthanide phosphonate [Ln7(PO3)6(COO)12] core was obtained. This core exhibited as a rare highly 18-connected node and was linked by the 3-connected pbpdc4- ligand, forming a (3,18)-connected framework with a novel topology of {43}6{438·676·839}. Read More

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Insights into the substrate discrimination mechanisms of methyl-CpG-binding domain 4.

Biochem J 2021 May 7. Epub 2021 May 7.

The University of Texas at Austin, Austin, Texas, United States.

G:T mismatches, the major mispairs generated during DNA metabolism, are repaired in part by mismatch-specific DNA glycosylases such as methyl-CpG-binding domain 4 (MBD4) and thymine DNA glycosylase (TDG). Mismatch-specific DNA glycosylases must discriminate the mismatches against million-fold excess correct base pairs. MBD4 efficiently removes thymine opposite guanine but not opposite adenine. Read More

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Eshelby untwisting.

Chem Commun (Camb) 2021 May 7. Epub 2021 May 7.

Department of Chemistry and the Molecular Design Institute, New York University, 100 Washington Square East, New York, NY 10003-6688, USA.

The concept of Eshelby untwisting, the effect of an axial screw dislocation driving an intrinsically twisted nanocrystal towards a straighter configuration more consistent with long-range translational symmetry, is introduced here. Force-field simulations of nanorods built from the enantiomorphous (space groups, P3121 and P3221) crystal structures of benzil (C6H5-C(O)-C(O)-C6H5) were previously shown to twist in opposite directions, even in the absence of dislocations. Here, both right- and left-handed screw dislocations were introduced into benzil nanorods in silico. Read More

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Analysis based on Monte Carlo simulation: How effective is tigecycline in routine antimicrobial therapy?

Int J Clin Pharmacol Ther 2021 May 7. Epub 2021 May 7.

Objective: This paper aims to assess the efficacy of tigecycline in the treatment of several different infections from a pharmacokinetic/pharmacodynamic (PK/PD) perspective.

Materials And Methods: The minimum inhibitory concentration (MIC) test strip test was used to determine the MICs of clinical isolates of tigecycline. A 5,000-subjects simulation was performed by Crystal Ball software to calculate the probability of achieving the required PK/PD exposure. Read More

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Novel Spin-Orbit Torque Generation at Room Temperature in an All-Oxide Epitaxial La Sr MnO /SrIrO System.

Adv Mater 2021 May 7:e2008269. Epub 2021 May 7.

Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.

Spin-orbit torques (SOTs) that arise from materials with large spin-orbit coupling offer a new pathway for energy-efficient and fast magnetic information storage. SOTs in conventional heavy metals and topological insulators are explored extensively, while 5d transition metal oxides, which also host ions with strong spin-orbit coupling, are a relatively new territory in the field of spintronics. An all-oxide, SrTiO (STO)//La Sr MnO (LSMO)/SrIrO (SIO) heterostructure with lattice-matched crystal structure is synthesized, exhibiting an epitaxial and atomically sharp interface between the ferromagnetic LSMO and the high spin-orbit-coupled metal SIO. Read More

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A novel sodium-fluorescent crystal.

R Soc Open Sci 2021 Mar 10;8(3):201987. Epub 2021 Mar 10.

School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China.

In this work, a novel sodium-fluorescent crystal (Na-FS) was synthesized from 4-dimethylaminobenzoic acid and sodium hydroxide by one-pot hydrothermal method. The structure and conformation of Na-FS were confirmed by single-crystal X-ray diffraction and scanning electron microscope, and the optical properties were studied by fluorescence spectrometer. The results showed that: Na-FS was a triclinic crystal, space group was P-1, cell parameters , and were 10. Read More

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Study on the photoelectrical performance of anodized titanium sheets.

R Soc Open Sci 2021 Mar 10;8(3):201778. Epub 2021 Mar 10.

School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, People's Republic of China.

Anodization is a widely used method to obtain multicoloured oxidized titanium sheets. However, most researchers paid great attention to the colour-related properties instead of photoelectrical properties of titanium oxide film obtained by anodization. In this work, to study their photoelectrical properties, a series of multicoloured oxidized titanium sheets were prepared by anodization method, and UV-vis absorption and photocurrents were tested. Read More

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Sensitive, Reusable, Surface-Enhanced Raman Scattering Sensors Constructed with a 3D Graphene/Si Hybrid.

ACS Appl Mater Interfaces 2021 May 7. Epub 2021 May 7.

Department of Microelectronic Science and Engineering, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China.

Surface-enhanced Raman scattering (SERS) substrates based on graphene and its derivatives have recently attracted attention among those interested in the detection of trace molecules; however, these substrates generally show poor uniformity, an unsatisfactory enhancement factor, and require a complex fabrication process. Herein, we design and fabricate three-dimensional (3D) graphene/silicon (3D-Gr/Si) heterojunction SERS substrates to detect various types of molecules. Notably, the detection limit of 3D-Gr/Si can reach 10 M for rhodamine 6G (R6G) and rhodamine B (RB), 10 M for crystal violet (CRV), copper(II) phthalocyanine (CuPc), and methylene blue (MB), 10 M for dopamine (DA), 10 M for bovine serum albumin (BSA), and 10 M for melamine (Mel), which is superior to most reported graphene-based SERS substrates. Read More

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Suppressing ion migration of CsPbBrxI3-x nanocrystals by Nickel doping and the application in high-efficiency WLEDs.

Nanotechnology 2021 May 6. Epub 2021 May 6.

School of Materials and Engineering, Hefei University of Technology, Tunxi Road, Hefei, 230009, CHINA.

All inorganic perovskite nanocrystals CsPbX3(X=Cl, Br, I) are the great potential candidates for the application of high-performance light emitting diodes (LED) due to their high Photoluminescence Quantum Yield (PLQY), high defect tolerance, narrow full-width half-maximum (FWHM) and tunable wavelength of 410-700nm. However, the application of red-emitting (630-650nm) CsPbBrxI3-x nanocrystals are perplexed by phase segregation due to the composition of mixed halides and the difference in halide ion mobility. Herein, we provide an effective strategy to suppressing the migration of Br/I ions through Ni2+ doping via a facile Hot-Injection method and the PLQY was improved as well. Read More

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Structure driven magnetic correlations and magnetodielectric coupling in 6H - perovskite BaDyRuO.

J Phys Condens Matter 2021 May 6. Epub 2021 May 6.

School of Basic Sciences, Indian Institute of Technology Mandi, School of Basic Sciences, Indian Institute of Technology Mandi, Himachal Pradesh, Mandi, Himachal Pradesh, 175075, INDIA.

The 6H-perovskites Ba(R/M)RuO(R = rare earth, M = transition metal) exhibit complex magnetism and have been extensively studied recently for their magnetodielectric (MD) properties. Here, we present a detailed study of structural, magnetic, thermodynamic and MD properties of a 6H-perovskite BaDyRuO. This compound is found to undergo long range antiferromagnetic (AFM) ordering below ∽ 5. Read More

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How the Protein Data Bank changed biology: An introduction to the JBC Reviews thematic series, Part 2.

J Biol Chem 2021 May 3:100748. Epub 2021 May 3.

Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Department of Biological Sciences and Bridge Institute, University of Southern California, Los Angeles, CA, 90089, USA.

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How structural biology transformed studies of transcription regulation.

J Biol Chem 2021 May 3:100741. Epub 2021 May 3.

Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205. Electronic address:

The past four decades have seen remarkable advances in our understanding of the structural basis of gene regulation. Technological advances in protein expression, nucleic acid synthesis and structural biology made it possible to study the proteins that regulate transcription in the context of ever larger complexes containing proteins bound to DNA. This review, written on the occasion of the 50 anniversary of the founding of the Protein Data Bank (PDB) focuses on the insights gained from structural studies of protein-DNA complexes, and the role the PDB has played in driving this research. Read More

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From structure to the dynamic regulation of a molecular switch: A journey over three decades.

J Biol Chem 2021 May 3:100746. Epub 2021 May 3.

Department of Chemistry and Biochemistry, University of California at San Diego, United States; San Diego Supercomputer Center, University of California, San Diego, United States.

It is difficult to imagine where the signaling community would be today without the Protein Data Bank (PDB). This visionary resource, established in the 1970s, has been an essential partner for sharing information between academics and industry for over three decades. We describe here the history of our journey with the protein kinases using cAMP-dependent protein kinase (PKA) as a prototype. Read More

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Crystal structures of NAD-linked isocitrate dehydrogenase from the green alga Ostreococcus tauri and its evolutionary relationship with eukaryotic NADP-linked homologs.

Arch Biochem Biophys 2021 May 3:108898. Epub 2021 May 3.

Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, No.1 Beijing East Road, College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China. Electronic address:

NAD-linked isocitrate dehydrogenases (NAD-IDHs) catalyze the oxidative decarboxylation of isocitrate into α-ketoglutarate. Previously, we identified a novel phylogenetic clade including NAD-IDHs from several algae in the type II subfamily, represented by homodimeric NAD-IDH from Ostreococcus tauri (OtIDH). However, due to its lack of a crystalline structure, the molecular mechanisms of the ligand binding and catalysis of OtIDH are little known. Read More

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The Contribution of Biophysics and Structural Biology to Current Advances in COVID-19.

Annu Rev Biophys 2021 May;50:493-523

Biomedical Research Institute (BIOMED), Catholic University of Argentina (UCA)-National Scientific and Technical Research Council, Argentina (CONICET), C1107AFF Buenos Aires, Argentina; email:

Critical to viral infection are the multiple interactions between viral proteins and host-cell counterparts. The first such interaction is the recognition of viral envelope proteins by surface receptors that normally fulfil other physiological roles, a hijacking mechanism perfected over the course of evolution. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has successfully adopted this strategy using its spike glycoprotein to dock on the membrane-bound metalloprotease angiotensin-converting enzyme 2 (ACE2). Read More

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Mutagenesis and homology modeling reveal a predicted pocket of lysophosphatidylcholine acyltransferase 2 to catch Acyl-CoA.

FASEB J 2021 Jun;35(6):e21501

Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan.

Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator that elicits various cellular functions and promotes several pathological events, including anaphylaxis and neuropathic pain. PAF is biosynthesized by two types of lyso-PAF acetyltransferases: lysophosphatidylcholine acyltransferase 1 (LPCAT1) and LPCAT2, which are constitutive and inducible forms of lyso-PAF acetyltransferase, respectively. Because LPCAT2 mainly produces PAF under inflammatory stimuli, understanding the structure of LPCAT2 is important for developing specific drugs against PAF-related inflammatory diseases. Read More

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Crystal structure of SARS-CoV-2 nsp10 bound to nsp14-ExoN domain reveals an exoribonuclease with both structural and functional integrity.

Nucleic Acids Res 2021 May 6. Epub 2021 May 6.

West China Hospital Emergency Department (WCHED), State Key Laboratory of Biotherapy and Cancer Center, West China Hospital and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, Sichuan 610041, China.

The emergence of SARS-CoV-2 infection has posed unprecedented threat to global public health. The virus-encoded non-structural protein 14 (nsp14) is a bi-functional enzyme consisting of an exoribonuclease (ExoN) domain and a methyltransferase (MTase) domain and plays a pivotal role in viral replication. Here, we report the structure of SARS-CoV-2 nsp14-ExoN domain bound to its co-factor nsp10 and show that, compared to the SARS-CoV nsp10/nsp14-full-length complex, SARS-CoV-2 nsp14-ExoN retains an integral exoribonuclease fold and preserves an active configuration in the catalytic center. Read More

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Optoelectronics and Nanophotonics of Vapor-Liquid-Solid Grown GaSe van der Waals Nanoribbons.

Nano Lett 2021 May 6. Epub 2021 May 6.

Department of Mechanical & Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.

2D/layered semiconductors are of interest for fundamental studies and for applications in optoelectronics and photonics. Work to date focused on extended crystals, produced by exfoliation or growth and investigated by diffraction-limited spectroscopy. Processes such as vapor-liquid-solid (VLS) growth carry potential for mass-producing nanostructured van der Waals semiconductors with exceptionally high crystal quality and optoelectronic/photonic properties at least on par with those of extended flakes. Read More

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Synthesis of large-area monolayer and few-layer MoSe continuous films by chemical vapor deposition without hydrogen assistance and formation mechanism.

Nanoscale 2021 May 6. Epub 2021 May 6.

Tianjin Key Laboratory of Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China. and Key Laboratory of Display Materials and Photoelectric Devices, National Demonstration Center for Experimental Function Materials Education, Institute of Functional Crystal, Tianjin University of Technology, Ministry of Education, Tianjin 300384, China.

Two dimensional (2D) MoSe2 with a layered structure has attracted extensive research due to its excellent electronic and optical properties. The controlled synthesis of large-scale and high-quality MoSe2 is highly desirable but still remains challenging. Ambient pressure chemical vapor deposition (APCVD) is an excellent method for the synthesis of 2D materials but the inevitable use of hydrogen during the growth and the easy formation of cracks in the ultrathin films still need to be solved. Read More

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WOI and WOI: metallic phases in the chemical transport reaction of tungsten.

Dalton Trans 2021 May 6. Epub 2021 May 6.

Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.

The crystal structures of the hitherto unknown phase W2O3I4 and of WO2I2, a compound that is known to play an important role in the chemical vapor transport of elemental tungsten are reported. We demonstrate that WO2I2 transforms into W2O3I4, and then into WO2 with increasing temperature. Crystals of WO2I2 appear as thin platelets, showing metallic luster; crystals of W2O3I4 appear as black colored needle-shaped platelets. Read More

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Structure, DFT studies and evaluation of catechol oxidase (CO) mimic activity of mononuclear Co(II) complexes derived from aminoalcohols: an experimental and theoretical approach.

J Biomol Struct Dyn 2021 May 6:1-11. Epub 2021 May 6.

Functional Inorganic Materials Lab (FIML), Department of Chemistry, Aligarh Muslim University, Aligarh, India.

The impetus to modeling of enzyme mimics comes from their potential to provide insight to the alternate mechanistic pathways of the native enzymes. The present study demonstrates the syntheses and characterization of two different cobalt(II) complexes, [Co(pdm)(Phen)Cl]Cl·HO () and [Co(pmmH)(SCN)] () with the aminoalcohol ligands such as pyridine-2,6-dimethanol (pdmH) or 2-pyridinemonomethanol (pmmH) and their assessment as catechol oxidase (CO) enzyme mimic. Single Crystal X-ray diffraction and powder X-ray diffraction data suggest the octahedral environment around the Co(II) ion and the complexes form extensive 1D or 2D propagating network as a result of non-covalent interactions (O···H and C-H···π). Read More

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Combined MD and QM/MM Investigations of Hydride Reduction of 5α-Dihydrotestosterone Catalyzed by Human 3α-Hydroxysteroid Dehydrogenase Type 3: Importance of Noncovalent Interactions.

J Phys Chem B 2021 May 6. Epub 2021 May 6.

Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan.

3α-Hydroxysteroid dehydrogenase (3α-HSD) is an enzyme that is essential in the regulation of the concentration of 5α-dihydrotestosterone (5α-DHT) in the prostate. It catalyzes the hydride reduction of 5α-DHT to 3α-androstanediol, which activates androgen receptors. Elucidating details about the hydride reduction of 5α-DHT by 3α-HSD and the environment around the active site of the enzyme could lead to the development of effective drugs for the treatment of prostate cancer. Read More

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