The rpiB gene, encoding ribose-5-phosphate isomerase (RpiB) from Clostridium thermocellum, was cloned and expressed in Escherichia coli. RpiB converted D-psicose into D-allose but it did not convert D-xylose, L-rhamnose, D-altrose or D-galactose. The production of D-allose by RpiB was maximal at pH 7.5 and 65 degrees C for 30 min. The half-lives of the enzyme at 50 degrees C and 65 degrees C were 96 h and 4.7 h, respectively. Under stable conditions of pH 7.5 and 50 degrees C, 165 g D-allose l(-1 ) was produced without by-products from 500 g D-psicose l(-1) after 6 h.
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http://dx.doi.org/10.1007/s10529-007-9393-7 | DOI Listing |
Int J Biol Macromol
December 2024
School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China. Electronic address:
The cascade of sugar isomerases is one of the most practical methods for producing rare sugars, and enzyme immobilization endows it with high economic efficiency, operational convenience and reusability. However, the most employed cross-linker glutaraldehyde (GA) has the disadvantages of enzyme deactivation and limitation of substrate binding. Herein, three compounds, glyoxal, GA, and 2,5-furandicarboxaldehyde (DFF) were evaluated within a previously developed cascade comprising ribose-5-phosphate isomerase and D-tagatose-3-epimerase to prepare D-ribulose form D-xylose.
View Article and Find Full Text PDFCells
November 2024
Engelhardt Institute of Molecular Biology, Russian Academy of Science, 119991 Moscow, Russia.
In cells, the main enzymes involved in pentose interconversion are ribose-5-phosphate isomerases RpiA and RpiB and ribulose-5-phosphate epimerase Rpe. The inactivation of limits ribose-5-phosphate (R5P) synthesis via the oxidative branch of the pentose phosphate pathway (PPP) and unexpectedly results in antibiotic supersensitivity. This type of metabolism is accompanied by significant changes in the level of reducing equivalents of NADPH and glutathione, as well as a sharp drop in the ATP pool.
View Article and Find Full Text PDFCommun Biol
November 2024
MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
EMBO J
July 2024
Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, 3168, Australia.
During infection viruses hijack host cell metabolism to promote their replication. Here, analysis of metabolite alterations in macrophages exposed to poly I:C recognises that the antiviral effector Protein Kinase RNA-activated (PKR) suppresses glucose breakdown within the pentose phosphate pathway (PPP). This pathway runs parallel to central glycolysis and is critical to producing NADPH and pentose precursors for nucleotides.
View Article and Find Full Text PDFFood Sci Biotechnol
June 2024
School of Chemistry and Life Sciences, Suzhou University of Science and Technology, 215009 Suzhou, People's Republic of China.
Enzymatic preparation of rare sugars as an alternative to traditional sweeteners is an effective strategy to achieve a low-calorie healthy diet. Ribose-5-phosphate isomerase B (RpiB) is a key enzyme in the non-oxidative branch of the catalytic pentose phosphate pathway. Here, we investigated the potential of ZXL1 ( ZXL1) derived RpiB (CfRpiB) in D-allose preparation.
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