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Penicillium camemberti galacturonate reductase: C-1 oxidation/reduction of uronic acids and substrate inhibition mitigation by aldonic acids
- Source :
- International Journal of Biological Macromolecules. 153:1090-1098
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- The enzyme galacturonate oxidoreductase PcGOR from Penicillium camemberti reduces the C-1 carbon of D-glucuronate and C-4 epimer D-galacturonate to their corresponding aldonic acids, important reactions in both pectin catabolism and ascorbate biosynthesis. PcGOR was active on both glucuronic acid and galacturonic acid, with similar substrate specificities (kcat/Km) using the preferred co-substrate NADPH. Substrate acceptance extended to lactone congeners, and D-glucurono-3,6-lactone was converted to L-gulono-1,4-lactone, an immediate precursor of ascorbate. Reaction with glucuronate showed only minor substrate inhibition, and the product L-gulonate and L-gulono-1,4-lactone were both found to be competitive inhibitors with Ki in the low mM range. In contrast, reaction with C-4 epimer galacturonate displayed marked substrate inhibition. Moreover, the product L-galactonate and L-galactono-1,4-lactone were observed to mitigate substrate inhibition by galacturonate, with the lactone having a greater effect than the acid.
- Subjects :
- Stereochemistry
Glucuronate
02 engineering and technology
Reductase
Biochemistry
03 medical and health sciences
chemistry.chemical_compound
NAD (+) and NADP (+) Dependent Alcohol Oxidoreductases
Structural Biology
Enzyme Stability
Amino Acid Sequence
Molecular Biology
030304 developmental biology
0303 health sciences
Aldaric acid
biology
Penicillium
Temperature
Sugar Acids
Substrate (chemistry)
General Medicine
021001 nanoscience & nanotechnology
Glucuronic acid
biology.organism_classification
Uronic Acids
chemistry
Penicillium camemberti
Aldonic acid
Epimer
0210 nano-technology
Oxidation-Reduction
NADP
Subjects
Details
- ISSN :
- 01418130
- Volume :
- 153
- Database :
- OpenAIRE
- Journal :
- International Journal of Biological Macromolecules
- Accession number :
- edsair.doi.dedup.....8f46e144906446b9c7d2e4bb931bcc4b
- Full Text :
- https://doi.org/10.1016/j.ijbiomac.2019.10.239