The association and dissociation rate constants of eight different E. coli aminoacyl-tRNAs (aa-tRNAs) for E. coli ribosomes programmed with mRNAs of defined sequences were determined. Identical association and dissociation rate constants were observed for all eight aa-tRNAs in both the ribosomal A and P sites despite substantial differences in tRNA sequence, the type of esterified amino acid, and posttranscriptional modifications. These results indicate that the overall binding of all aa-tRNAs to the ribosome is uniform. However, when either the esterified amino acid or the tRNA modifications were removed, binding was no longer uniform. These results suggest that differences in tRNA sequences and tRNA modifications have evolved to offset differential thermodynamic contributions of the esterified amino acid and the codon-anticodon interaction so that ribosomal binding of all aa-tRNAs remains uniform.
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http://dx.doi.org/10.1016/j.molcel.2004.10.030 | DOI Listing |
Langmuir
December 2024
Division of Craniofacial Function Engineering (Division of Biomaterials Science and Engineering), Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan.
This study was designed to investigate how the strength of the interaction between octacalcium phosphate (OCP) and modified chondroitin-A sulfate (CS-A), a glycosaminoglycan, regulates the adsorption-desorption of cytokines and subsequently affects the osteoblastic differentiation of mesenchymal stem cells (MSCs) in vitro. The utilization of cytokines produced by cells, such as macrophages, stimulated by the hydrolysis of OCP, is expected to enhance the bone regeneration capacity of the OCP. CS-Na was used to modify CS-A on the OCP immobilized with the amino group through electrostatic interactions.
View Article and Find Full Text PDFAnim Nutr
December 2024
Laboratory of Fish and Shellfish Nutrition, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
A six-week feeding trial was carried out to determine the feasibility of cottonseed oil (CSO) as a viable substitute for fish oil (FO) in the commercial diet of swimming crabs. Ninety healthy swimming crabs (initial body weight 34.28 ± 0.
View Article and Find Full Text PDFJ Lipid Res
November 2024
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Health Sciences Mass Spectrometry Core, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address:
The enzymatic oxidation of arachidonic acid is proposed to yield trihydroxytetraene species (termed lipoxins) that resolve inflammation via ligand activation of the formyl peptide receptor, FPR2. While cell and murine models activate signaling responses to synthetic lipoxins, primarily lipoxin A (LXA), there are expanding concerns about the reported biological formation, detection, and signaling mechanisms ascribed to LXA and related di- and tri-hydroxy ω-6 and ω-3 fatty acids. The generation and signaling actions of LXA and its primary 15-oxo metabolite were assessed in control, lipopolysaccharide-activated, and arachidonic acid-supplemented RAW264.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China; Research Centre of Modern Analytical Technology, Tianjin University of Science & Technology, Tianjin 300457, China; State Key Laboratory of Chinese Medicine Modernization, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China. Electronic address:
α-Glucosidase is considered to be one of the effective targets for the treatment of type 2 diabetes. This study examined the inhibitory mechanisms of eight catechins on α-glucosidase, including both the free forms (C, EC, GC, EGC) and esterified forms (CG, ECG, GCG, EGCG). Enzyme kinetics and molecular docking studies demonstrated that catechins primarily inhibit α-glucosidase by binding through hydrogen bonds and hydrophobic interactions, with esterified catechins exhibiting stronger inhibitory effects.
View Article and Find Full Text PDFFoods
September 2024
Faculty of Food Science and Engineering, Kunming University of Science and Technology, Yunnan Engineering Research Center for Fruit & Vegetable Products, Yunnan Key Laboratory of Plateau Food Advanced Manufacturing, Kunming 650500, China.
Seeking food-derived antioxidants and inhibitors of α-glucosidase and α-amylase has been recognized as an effective way for managing diabetes. Coffee silver skin (CSS) is rich in phenolic compounds, which may be potential agents as antioxidants and for α-glucosidase and α-amylase inhibition. But whether phenolics in different forms show similar bioactivity remains unknown.
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