The ascorbate oxidase obtained from a microorganism, Acremonium sp. HI-25 (molecular weight, 80 kDa; monomeric protein), was studied with respect to atomic absorption, EPR, absorption spectra, circular dichroism (CD) spectra, and steady-state kinetics. The enzyme was found to be a multicopper protein, containing four copper atoms of three kinds, types 1, 2, and 3 copper, in the ratio of 1:1:2. The EPR parameters of the type 1 and 2 copper atoms in the ascorbate oxidase are very similar to those in the case of the ascorbate oxidase obtained from cucumber, which is a dimeric protein. The apparent Km and kcat values for ascorbic acid of the ascorbate oxidase from Acremonium sp. HI-25 are almost the same as those of the monomeric unit of the ascorbate oxidase from cucumber.
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http://dx.doi.org/10.1093/oxfordjournals.jbchem.a124420 | DOI Listing |
Anal Chem
January 2025
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
A novel dual-mode microfluidic sensing platform integrating photoelectrochemical (PEC) and fluorescence (FL) sensors was developed for the sensitive monitoring of heart fatty acid binding protein (h-FABP). First, BiVO/AgInS (BVAIS) composites with excellent photoelectric activity were synthesized as sensing matrices. The BVAIS heterojunction with a well-matched internal energy level structure provided a stable photocurrent.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA.
Ocean warming due to climate change endangers coral reefs, and regional nitrogen overloading exacerbates the vulnerability of reef-building corals as the dual stress disrupts coral-Symbiodiniaceae mutualism. Different forms of nitrogen may create different interactive effects with thermal stress, but the underlying mechanisms remain elusive. To address the gap, we measured and compared the physiological and transcriptional responses of the Symbiodiniaceae to heat stress (31°C) when supplied with different types of nitrogen (nitrate, ammonium, or urea).
View Article and Find Full Text PDFAntioxidants (Basel)
December 2024
College of Forestry, Gansu Agricultural University, Lanzhou 730070, China.
Wolfberry () is a vital economic tree species in northwest China, but root rot caused by occurs frequently, which seriously endangers the quality and yield of wolfberry. In this study, potato glycoside alkaloids (PGAs), a plant-derived active substance, were used as materials to explore its inhibitory effect on . By analyzing the changes of reactive oxygen species (ROS) level, antioxidant capacity, and apoptosis, the role of PGAs-mediated oxidative stress in inducing apoptosis of was revealed.
View Article and Find Full Text PDFFunct Plant Biol
January 2025
Discipline of Life Sciences, School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi 110068, India.
The aim of this study was to decipher the reprogramming of protective machineries and sulfur metabolism, as responses to time-dependent effect of fluoride stress for 10 and 20days in two indica rice (Oryza sativa ) varieties. Unregulated accumulation of fluoride via chloride channels (CLC1 and CLC2) in 10-day-old (cv. Khitish) and 20-day-old (cv.
View Article and Find Full Text PDFTalanta
December 2024
Analytical Chemistry Division, Chemistry Department, Lomonosov Moscow State University, 119234, Moscow, Russia. Electronic address:
Novel and simple spectrophotometric and distance based procedures for thiols (L-cysteine, N-acetylcysteine, and glutathione) determination in biological fluids and pharmaceuticals have been proposed based on their inhibitory action on the oxidation of catechol in the presence of Agaricus bisporus crude extract (ABE). The influence of L-glycine, L-alanine, L-proline, L-methionine, L-cystine, ascorbic acid, uric acid, and bilirubin on the thiol determination has been investigated. Uric acid, bilirubin, L-cystine (oxidized thiol), and L-amino acids do not interfere with the determination.
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