The effect of L-arginine on nitrergic transmission and its alteration with reactive oxygen species (ROS) were investigated. L-arginine potentiated the relaxation response induced by electrical field stimulation in rat anococygeus muscle. This effect was inhibited by L-lysine, a cationic amino acid using y+ L and y+ transport systems in a similar way with L-arginine. The neutral amino acid L-leucine, which uses only y+ L system as a transport mechanism, inhibited this potentiation at only low frequency stimulation. Electrolysis of the physiological solution did not change the responses to electrical field stimulation, but inhibited the potentiation elicited by L-arginine that was prevented in the presence of mannitol and N-acetyl-L-cysteine. In conclusion, L-arginine is transported via y+ system predominantly to potentiate the relaxation response to nitrergic nerve stimulation in rat anococcygeus muscle. ROS, primarily hydroxyl radicals inhibited L-arginine-induced potentiation probably by interacting with the y+ amino acid transport system.
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BMC Microbiol
December 2024
State Key Laboratory Incubation Base for Conservation and Utilization of Bio-Resource in Tarim Basin, Alar, Xinjiang Uygur Autonomous Region, 843300, China.
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New Drug Research & Development Center of North China Pharmaceutical Group Corporation, National Engineering Research Center of Microbial Medicine, Shijiazhuang, 052165, China.
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CAS Key Laboratory of Agroecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, 410125, China.
This study aimed to investigate the temporal accumulation of odor fatty acids (OFAs) in the dorsal subcutaneous adipose tissue, and uncover their dynamic regulatory metabolic pathways from the transcriptomic perspective in lambs from birth to market. Thirty-two Hulun Buir lambs were selected and randomly assigned to four different sampling stages following their growth trajectories: neonatal (day 1), weaning (day 75), mid-fattening (day 150), and late-fattening (day 180) stages. Results indicated that the contents of three OFAs increased progressively as lambs matured, with the most drastic change occurred at mid-fattening vs.
View Article and Find Full Text PDFSci Rep
December 2024
Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Waldeyerstrasse 15, D-48149, Münster, Germany.
The heparan sulfate (HS)-rich extracellular matrix (ECM) serves as an initial interaction site for the homotrimeric spike (S) protein of SARS-CoV-2 to facilitate subsequent docking to angiotensin-converting enzyme 2 (ACE2) receptors and cellular infection. More recent variants, notably Omicron, have evolved by swapping several amino acids to positively charged residues to enhance the interaction of the S-protein trimer with the negatively charged HS. However, these enhanced interactions may reduce Omicron's ability to move through the HS-rich ECM to effectively find ACE2 receptors and infect cells, raising the question of how to mechanistically explain HS-associated viral movement.
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December 2024
Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, 40127, Bologna, Italy.
This manuscript details the application of Isothermal Titration Calorimetry (ITC) to characterize the kinetics of 3CL, the main protease from the Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2), and its inhibition by Ensitrelvir, a known non-covalent inhibitor. 3CL is essential for producing the proteins necessary for viral infection, which led to the COVID-19 pandemic. The ITC-based assay provided rapid and reliable measurements of 3CL activity, allowing for the direct derivation of the kinetic enzymatic constants K and k by monitoring the thermal power required to maintain a constant temperature as the substrate is consumed.
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