This paper reports on a coupled approach to determining the structure of the gramicidin A ion channel, utilizing solid state nuclear magnetic resonance (NMR) of isotopically labeled gramicidin channels aligned parallel to the magnetic field direction, and molecular dynamics (MD). MD computations using an idealized right-handed beta-helix as a starting point produce a refined molecular structure that is in excellent agreement with atomic resolution solid state NMR data. The data provided by NMR and MD are complementary to each other. When applied in a coordinated manner they provide a powerful approach to structure determination in molecular systems not readily amenable to x-ray diffraction.
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http://dx.doi.org/10.1016/S0006-3495(91)82131-2 | DOI Listing |
Cell Mol Life Sci
January 2025
Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Hypoxia, or a state of low tissue oxygenation, has been characterized as an important feature of solid tumors that is related to aggressive phenotypes. The cellular response to hypoxia is controlled by Hypoxia-inducible factors (HIFs), a family of transcription factors. HIFs promote the transcription of gene products that play a role in tumor progression including proliferation, angiogenesis, metastasis, and drug resistance.
View Article and Find Full Text PDFLangmuir
January 2025
Hubei Key Laboratory of Oil and Gas Exploration and Development Theory and Technology (China University of Geosciences), Wuhan 430074, China.
The strong solid-liquid interaction leads to the complicated occurrence characteristics of shale oil. However, the solid-liquid interface interaction and its controls of the occurrence state of shale oil are poorly understood on the molecular scale. In this work, the adsorption behavior and occurrence state of shale oil in pores of organic/inorganic matter under reservoir conditions were investigated by using grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Fudan University, 2005 Huhu Rd, Shanghai, CHINA.
All-solid-state lithium metal batteries are regarded as next-generation devices for energy storage due to their safety and high energy density. The issues of lithium dendrites and poor mechanical compatibility with electrodes present the need for developing solid-state electrolytes with high stiffness and damping, but it is a contradictory relationship. Here, inspired by the superstructure of tooth enamel, we develop a composite solid-state electrolyte composed of amorphous ceramic nanotube arrays intertwined with solid polymer electrolytes.
View Article and Find Full Text PDFAnal Methods
November 2017
Guangxi Zhuang Autonomous Region Forestry Research Institute, Nanning 530002, China.
1,4-Dihydroxyanthraquinone (1,4-DHAQ, a fluorophore) doped carbon nanotubes@cellulose (1,4-DHAQ-doped CNTs@CL) nanofibrous membranes have been prepared electrospinning and subsequent deacetylation in this work. They have been successfully applied for highly sensitive detection of Cu in aqueous solution. The surface area per unit mass (S/M) ratio of the nanofibrous membranes was enhanced by incorporating the CNTs into cellulose.
View Article and Find Full Text PDFHuman epidermal growth factor receptor 2 (HER2, also known as ERBB2) signaling promotes cell growth and differentiation, and is overexpressed in several tumor types, including breast, gastric and colorectal cancer. HER2-targeted therapies have shown clinical activity against these tumor types, resulting in regulatory approvals. However, the efficacy of HER2 therapies in tumors with HER2 mutations has not been widely investigated.
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