The gene coding for O-acetylserine sulfhydrylase (OASS) from E. coli K12 was cloned into the vector pBR322 plasmid and expressed in a cysk mutant strain of E. coli that is deficient in O-acetylserine sulfhydrylase (OASS-). The clone containing the OASS gene was selected by using tetracycline-ammonium bismuth citrate medium. Retransformation of the hybrid plasmid into competent cysk mutant cells resulted in the recovery of a clone containing normal levels of O-acetylserine sulfhydrylase. Negative selection of retransformed cysk cells on 1,2,4-triazole plates resulted in the complete inhibition of growth indicating the presence of a functional OASS gene. The ability of the new clone to convert azide to its mutagenic metabolite was tested. Cultures of the clone cells containing significant levels of OASS activity were able to produce a mutagenic product from azide and O-acetylserine as tested on Salmonella typhimurium TA1530. This cloning method could be applied also to clone the same gene from eukaryotic sources.
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http://dx.doi.org/10.1016/0165-7992(90)90043-j | DOI Listing |
Andrology
January 2025
Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey.
Background: Androgen deprivation is associated with erectile dysfunction (ED). In different animal models, sulfur dioxide (SO) donors NaSO and NaHSO reduced oxidative stress, fibrosis, and inflammation which contribute to the pathogenesis of androgen deprivation-induced ED, however the effect of SO donors on ED in castrated rats were not known.
Objective: To investigate the therapeutic effect of SO donors, NaSO/NaHSO, on ED in castrated rat model.
Biomolecules
November 2024
Department of Biology, Washington University, St. Louis, MO 63146, USA.
Mitochondrial holocytochrome c synthase (HCCS) is an essential protein in assembling cytochrome c (cyt c) of the electron transport system. HCCS binds heme and covalently attaches the two vinyls of heme to two cysteine thiols of the cyt c CXXCH motif. Human HCCS recognizes both cyt c and cytochrome c of complex III (cytochrome bc).
View Article and Find Full Text PDFCommun Biol
January 2025
Georgia Cancer Center, Augusta University, Augusta, GA, 30912, USA.
The transsulfuration (TSS) pathway is an alternative source of cysteine for glutathione synthesis. Little of the TSS pathway in antioxidant capacity in sickle cell disease (SCD) is known. Here, we evaluate the effects of TSS pathway activation through cystathionine beta-synthase (CBS) to attenuate reactive oxygen species (ROS) and ferroptosis stresses in SCD.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India. Electronic address:
Biofilm formation is a key adaptive response of marine bacteria towards stress conditions. The protective mechanisms of biofilm matrixome proteins against heavy metals (Pb and Cd) induced oxidative damage in the marine bacterium Bacillus stercoris GST-03 was investigated. Exposure to heavy metals resulted in significant changes in cell morphology, biofilm formation, and matrixome composition.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, China; The International Peace Maternity and Child Health Hospital, School of Medicine. Shanghai Jiao Tong University, Shanghai 200030, China. Electronic address:
Hydrogen sulfide (HS) is an metabolic product of tuna during the spoilage, and relationship between HS and tuna quality has not been specifically studied. This study detected changes in HS content, HS precursor substances, and related enzymes based on the formation pathway of HS. HS content increased of tuna resulted in significant increases in contents of cystathionine β-synthase, cystathionine γ-lyase, 3-mercapto pyruvate sulfotransferase, cysteine aminotransferase and methionine, while content of cysteine decreased which provided HS formation.
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