As a polycation with diverse applications in biomedical and environmental engineering, polyethylenimine (PEI) can be synthesized with varying degrees of branching, polymerization, and can exist in different protonation states. There have been some interests in molecular modeling of PEI at all-atom or coarse-grained (CG) levels, but present CG models are limited to linear PEIs. Here we present the methodology to systematically categorize bond lengths, bond angles and dihedral angles, which allows us to model branched PEIs. The CG model was developed under the Martini scheme based on eight ~600 Da PEIs, with four different degree of branching at two different protonation states. Comparison of the CG model with all-atom simulations shows good agreement for both local (distributions for bonded interactions) and global (end-to-end distance, radius of gyration) properties, with and without salt. Compatibility of the PEI model with other CG bio-molecules developed under the Martini scheme will allow for large-scale simulations of many PEI-enabled processes. © 2018 Wiley Periodicals, Inc.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jcc.25747 | DOI Listing |
BMC Chem
January 2025
Energy Systems Engineering Department, Engineering Faculty, Adana Alparslan Türkeş Science and Technology University, 01250, Adana, Türkiye.
Although the antiallergic properties of compounds such as CAPE, Melatonin, Curcumin, and Vitamin C have been poorly discussed by experimental studies, the antiallergic properties of these famous molecules have never been discussed with calculations. The histamine-1 receptor (H1R) belongs to the family of rhodopsin-like G-protein-coupled receptors expressed in cells that mediate allergies and other pathophysiological diseases. In this study, pharmacological activities of FDA-approved second generation H1 antihistamines (Levocetirizine, desloratadine and fexofenadine) and molecules such as CAPE, Melatonin, Curcumin, Vitamin C, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) profiles, density functional theory (DFT), molecular docking, biological targets and activities were compared by calculating.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
January 2025
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston TX, United States of America; Department of Radiation Oncology, Amsterdam UMC, Amsterdam, The Netherlands.
Background: A detrimental association between radiation-induced lymphopenia (RIL) and oncologic outcomes in esophageal cancer patients has been established. However, an optimal metric for RIL remains undefined, but is important for application of this knowledge in clinical decision-making and trial designs. The aim of this study was to find the optimal RIL metric discerning survival.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, West Bengal 700032, India.
Designing catalysts for the selective reduction of CO, resulting in products having commercial value, is an important area of contemporary research. Several molecular catalysts have been reported to facilitate the reduction of CO (both electrochemical and photochemical) to yield 2e/2H electron-reduced products, CO and HCOOH, and selective reduction of CO beyond 2e/2H is rare. This is partly because the factors that control the selectivity of CO reduction beyond 2e are not yet understood.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Chemistry and Chemical Engineering Southeast University, Jiangning District, Nanjing, Jiangsu Province 211189, PR China. Electronic address:
Inkless paper made from photochromic materials has garnered significant interest owing to its potential to reduce both ink and paper pollution during production. In this research, we synthesized a dual-material film (EC-PVP/PGMEA/PMoA) and conducted a detailed investigation of its photochromic response to visible light and its microstructural properties. Initially, the film appeared as a translucent yellow, but upon exposure to visible light, it shifted to blue with a maximum absorption peak of 2.
View Article and Find Full Text PDFCell
December 2024
Key Laboratory Experimental Teratology of the Ministry of Education, New Cornerstone Science Laboratory, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong 250012, China; NHC Key Laboratory of Otorhinolaryngology, Qilu Hospital of Shandong University, Advanced Medical Research Institute, Shandong University, Jinan, China; Department of Physiology and Pathophysiology, State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, Beijing, China. Electronic address:
Animals have evolved pH-sensing membrane receptors, such as G-protein-coupled receptor 4 (GPR4), to monitor pH changes related to their physiology and generate adaptive reactions. However, the evolutionary trajectory and structural mechanism of proton sensing by GPR4 remain unresolved. Here, we observed a positive correlation between the optimal pH of GPR4 activity and the blood pH range across different species.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!