Covalent modification of purified Trigonopsis variabilis D-amino acid oxidase using maleimide-activated poly(ethylene glycol) 5000 yielded a stable bioconjugate in which three surface-exposed cysteine side chains were selectively derivatized. Compared with the native enzyme, the PEGylated variant displayed substantially (approximately 3.3-fold) slowed dissociation rate of FAD cofactor at 50 degrees C, and this caused a twofold thermostabilization of the enzyme activity. The stability under reaction conditions at 30 degrees C was also markedly enhanced in the PEG-oxidase conjugate. PEGylation did not affect steady-state kinetic parameters for oxidative deamination of D-methionine when 2,6-dichloroindophenol replaced dioxygen as the cosubstrate while it caused a ninefold decrease in substrate catalytic efficiency for the dioxygen-dependent reaction.
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http://dx.doi.org/10.1002/bit.21181 | DOI Listing |
aBIOTECH
June 2024
State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275 China.
Unlabelled: The CRISPR/Cas9 technology revolutionizes targeted gene knockout in diverse organisms including plants. However, screening edited alleles, particularly those with multiplex editing, from herbicide- or antibiotic-resistant transgenic plants and segregating out the transgene represent two laborious processes. Current solutions to facilitate these processes rely on different selection markers.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
May 2022
CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
Oxidases are a group of oxidoreductases and need molecular oxygen in the catalytic process. Vitreoscilla hemoglobin (VHb) can improve the growth and productivity of host cells under hypoxic conditions, rendering it attractive for industrial application. In this work, we demonstrated the addition of immobilized VHb increased the catalytic activity of immobilized D-amino acid oxidase of Trigonopsis variabilis by two-fold when catalyzing cephalosporin C under oxygen-limited conditions.
View Article and Find Full Text PDFBiomacromolecules
February 2021
Department of Biocatalysis, Institute of Catalysis and Petrochemistry (ICP) CSIC, Campus UAM, Cantoblanco, Madrid 28049, Spain.
The functionalization of the internal surface of macroporous carriers with glyoxyl groups has proven to highly stabilize a large variety of enzymes through multipoint covalent immobilization. In this work, we have translated the surface chemistry developed for the fabrication of glyoxyl-agarose carriers to macroporous cellulose (CEL). To that aim, CEL-based microbeads were functionalized with glyoxyl groups through a stepwise alkoxylation (or alkylation)/oxidation synthetic scheme.
View Article and Find Full Text PDFInt J Mol Sci
September 2019
Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
d-amino acid oxidase (DAAO, EC 1.4.3.
View Article and Find Full Text PDFBiotechnol Bioeng
December 2019
Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China.
S-Adenosyl-l-methionine (SAM) is an important small molecule compound widely used in treating various diseases. Although l-methionine is generally used, the low-cost dl-methionine is more suitable as the substrate for industrial production of SAM. However, d-methionine is inefficient for SAM formation due to the substrate-specificity of SAM synthetase.
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