The anion selectivity and conductance of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel are determined predominantly by interactions between permeant anions and the narrow region of the channel pore. This narrow region has therefore been described as functioning as the "selectivity filter" of the channel. Multiple pore-lining transmembrane segments (TMs) have previously been shown to contribute to the selectivity filter region. However, little is known about the three-dimensional organization of this region, or how multiple TMs combine to determine its functional properties. In the present study we have used patch clamp recording to identify changes in channel function associated with the formation of disulfide cross-links between cysteine residues introduced into different TMs within the selectivity filter. Cysteine introduced at position L102 in TM1 was able to form disulfide bonds with F337C and T338C in TM6, two positions that are known to play key roles in determining anion permeation properties. Consistent with this proximal arrangement of L102, F337 and T338, different mutations at L102 altered anion selectivity and conductance properties in a way that suggests that this residue plays an important role in determining selectivity filter function, albeit a much lesser role than that of F337. These results suggest an asymmetric three-dimensional arrangement of the key selectivity filter region of the pore, as well as having important implications regarding the molecular mechanism of anion permeation.
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http://dx.doi.org/10.1016/j.bbamem.2017.02.014 | DOI Listing |
BMC Med Imaging
January 2025
Department of Thoracic Surgery, The Fifth Clinical Medical College of Henan, University of Chinese Medicine (Zhengzhou People's Hospital), Zhengzhou, 450003, China.
Objective: In clinical practice, diagnosing the benignity and malignancy of solid-component-predominant pulmonary nodules is challenging, especially when 3D consolidation-to-tumor ratio (CTR) ≥ 50%, as malignant ones are more invasive. This study aims to develop and validate an AI-driven radiomics prediction model for such nodules to enhance diagnostic accuracy.
Methods: Data of 2,591 pulmonary nodules from five medical centers (Zhengzhou People's Hospital, etc.
Food Chem
January 2025
School of Chemistry and Life Science, Changchun University of Technology, 2055 Yanan Street, Changchun 130012, PR China; Advanced Institute of Materials Science, Changchun University of Technology, 2055 Yanan Street, Changchun 130012, PR China. Electronic address:
Resveratrol (Res), a natural antioxidant widely found in fruits, plays a crucial role in preventing various diseases. However, traditional detection methods usually rely on large amounts of toxic solvents, leading to high costs and potential health risks to researchers. In this work, an economical, green, rapid, and sensitive method for Res detection was developed using banana peel-derived nitrogen-doped carbon dots (BP-N-CDs) as fluorescent sensors.
View Article and Find Full Text PDFLuminescence
January 2025
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
Based on nitrogen and phosphorus co-doped carbon dots (NP-CDs), a direct, quick, and selective sensing probe for fluorometric detection of rutin has been developed. Utilizing ethylene diamine tetra acetic acid (EDTA) as a carbon and nitrogen source and diammonium hydrogen phosphate (NH)HPO as a nitrogen and phosphorus source. The NP-CDs were synthesized in less than 3 min with a straightforward one-step microwave pyrolysis process with a high quantum yield (63.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Rare earth elements (REEs) are essential for many clean energy technologies. Yet, they are a limited resource currently obtained through carbon-intensive mining. Here, bio-scaffolded proteins serve as simple, effective materials for the recovery of REEs.
View Article and Find Full Text PDFTransl Cancer Res
December 2024
Tokyo Metropolitan Cancer and Infectious Disease Center, Komagome Hospital, Tokyo, Japan.
Background: Numerous studies have demonstrated that immune cell infiltration is a significant predictor in the prognosis of those with breast cancer. This study aimed to develop a prognostic model for undifferentiated breast cancer using immune-related markers.
Methods: Differentially expressed genes (DEGs) and prognostic factors were identified from The Cancer Genome Atlas (TCGA) database.
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