Ribokinase (RK) was expressed in the Escherichia coli ER2566 cells harboring the constructed expression plasmid encompassing the rbsK gene, encoding ribokinase. The recombinant enzyme was purified from sonicated cells by double chromatography to afford a preparation that was ca. 90% pure and had specific activity of 75 micromol/min mg protein. Catalytic activity of RK: (i) is strongly dependent on the presence of monovalent cations (potassium>>>ammonium>cesium), and (ii) is cooperatively enhanced by divalent magnesium and manganese ions. Besides D-ribose and 2-deoxy-D-ribose, RK was found to catalyze the 5-O-phosphorylation of D-arabinose, D-xylose, and D-fructose in the presence of ATP, and potassium and magnesium ions; L-ribose and L-arabinose are not substrates for the recombinant enzyme. A new radiochemical method for monitoring the formation of D-pentofuranose-5-[32P]phosphates in the presence of [gamma-32P]ATP and RK is reported.
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http://dx.doi.org/10.1016/j.bmc.2006.05.057 | DOI Listing |
Sci Rep
January 2025
Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia.
Extracellular vesicles (EVs) are nanosized lipid bilayer particles released by various cellular organisms that carry an array of bioactive molecules. EVs have diagnostic potential, as they play a role in intercellular interspecies communication, and could be applied in drug delivery. In contrast to mammalian cell-derived EVs, the study of EVs from bacteria, particularly Gram-positive bacteria, received less research attention.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, Saulėtekio Av. 7, Vilnius 10257, Lithuania.
Enzymatic degradation of plastic pollution offers a promising environmentally friendly waste management strategy, however, suitable biocatalysts must be screened and developed. Traditional screening methods using soluble or solubilised polymers do not necessarily identify enzymes that are effective against solid or crystalline polymers. This study presents a simple, time-saving and cost-effective method for identifying microorganisms and enzymes capable of degrading polymeric films.
View Article and Find Full Text PDFEnzyme Microb Technol
January 2025
Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea. Electronic address:
Cell-free enzyme systems have emerged as a promising approach for producing various biometabolites, offering several advantages over traditional whole-cell systems. This study presents an approach to producing nicotinamide mononucleotide (NMN) by combining a Saccharomyces cerevisiae cell-free enzyme with a recombinant Escherichia coli cell-free enzyme. The system leverages the ATP generated by yeast during ethanol fermentation to produce NMN in the presence of nicotinamide (NAM) as a substrate.
View Article and Find Full Text PDFVet Parasitol
January 2025
Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, PR China; Chongqing Academy of Animal Sciences, Chongqing, PR China. Electronic address:
Toxoplasmosis is an important public health concern. Cats play a crucial role in increasing the risk of toxoplasmosis transmission to humans. Early diagnosis in cats is essential for the prevention and control of toxoplasmosis.
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