Spectrophotometric studies of the alkaline isomerization of horse heart and yeast cytochrome c show that the haemoproteins from Saccharomyces cerevisiae differ significantly from the mammalian cytochrome c. Apparent pKa values of 8.41, 8.40 and 8.73 for isol-1-(the methylated and unmethylated forms) and iso-2-cytochrome c respectively, from baker's yeast were determined and compared with the value of 9.40 found for horse heart cytochrome c. The transitions, measured by observing the decrease of the absorbance at 695 nm as the pH increases, have been found to strictly parallel the decrease in amplitude of the negative circular dichroism band centered at 417 nm. This observation gives additional evidence that this negative band is closely related to the ligation of the heme iron by the sulfur atom of methionine 8u for each of the four haemoproteins examined.
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J Phys Chem B
January 2025
Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Kraków 30-387, Poland.
Oxidized derivatives of cholesterol play an important role in the functioning of biomembranes. Unlike other biomolecules, which are physiologically active in only one enantiomeric form, some oxysterols exist endogenously as two stereoisomers that exhibit strictly different biological effects. In this paper, we focused our attention on 22-hydroxycholesterol (22-OH) epimers, 22()-OH and 22()-OH, and examined their properties in Langmuir monolayers spread at the air/water interface, using classical surface manometry complemented with Brewster angle microscopy (BAM) images of the film texture.
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March 2025
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China. Electronic address:
Perfluoroalkyl sulfonyl fluorides (PFASFs) have long been used as crucial synthetic intermediates in the production of various perfluoroalkyl substances. While, knowledge on the environmental occurrence and behaviors of PFASFs in the aquatic environment is still very limited, especially at the isomer-specific level. In this study, surface water, sediment, and fish samples were collected from the water environment near a wastewater treatment plant outlet, and analyzed them for five PFASFs.
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November 2024
College of Food Science and Engineering, Henan Key Laboratory of Cereal and Oil Food Safety and Nutrition, Henan University of Technology, Zhengzhou, Henan, 450001, China.
J Hazard Mater
November 2024
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Based on sampling from Xiaoqing River of China and elimination experiments, this study first investigated spatial/seasonal profiles and fates of phenylmethylsiloxanes (PMSs), as modified products of dimethylsiloxanes (DMSs), in natural waterbody. Overall, the average water (6.7 ng/L) and sediment (28.
View Article and Find Full Text PDFPhysiol Plant
November 2024
Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia.
Grapevine (Vitis vinifera L.) is the world's third most valuable horticultural crop, and the current environmental scenario is massively shifting the grape cultivation landscape. The increase in heatwaves and drought episodes alter fruit ripening, compromise grape yield and vine survival, intensifying the pressure on using limited water resources.
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