Site‐directed Mutagenesis Applied to Glucose Isomerase from <i>Streptomyces violaceoniger</i> and <i>Streptomyces olivochromogenes</i>

Sicard, P. J.; Leleu, J. B.; Duflot, Pierrick; Drocourt, Daniel; Marti, F.; Tiraby, Gérard; Petsko, Gregory A.; Glasfeld, Arthur

doi:10.1111/j.1749-6632.1990.tb18181.x

Cited by 6 publications

(1 citation statement)

References 11 publications

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“…Such studies have produced several crystal structures for xylose isomerases (for references, see reference 3) and have resulted in the sequencing of a number of genes encoding these enzymes (see GenBank). In addition, their catalytic mechanism has been investigated (for references, see reference 3), and approaches to improving their thermostability have been explored (27,30,34). Given the wealth of data available for a variety of xylose isomerases over a broad range of temperatures, these proteins represent an excellent model system for exploring enzyme thermostability (i.e., high temperature for irreversible denaturation) and thermophilicity (i.e., high temperature for optimal activity).…”

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confidence: 99%

xylA cloning and sequencing and biochemical characterization of xylose isomerase from Thermotoga neapolitana

Vieille

Hess

Kelly

et al. 1995

Appl Environ Microbiol

105

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The xylA gene coding for xylose isomerase from the hyperthermophile Thermotoga neapolitana 5068 was cloned, sequenced, and expressed in Escherichia coli. The gene encoded a polypeptide of 444 residues with a calculated molecular weight of 50,892. The native enzyme was a homotetramer with a molecular weight of 200,000. This xylose isomerase was a member of the family II enzymes (these differ from family I isomerases by the presence of approximately 50 additional residues at the amino terminus). The enzyme was extremely thermostable, with optimal activity above 95؇C. The xylose isomerase showed maximum activity at pH 7.1, but it had high relative activity over a broad pH range. The catalytic efficiency (k cat /K m) of the enzyme was essentially constant between 60 and 90؇C, and the catalytic efficiency decreased between 90 and 98؇C primarily because of a large increase in K m. The T. neapolitana xylose isomerase had a higher turnover number and a lower K m for glucose than other family II xylose isomerases. Comparisons with other xylose isomerases showed that the catalytic and cation binding regions were well conserved. Comparison of different xylose isomerase sequences showed that numbers of asparagine and glutamine residues decreased with increasing enzyme thermostability, presumably as a thermophilic strategy for diminishing the potential for chemical denaturation through deamidation at elevated temperatures.

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mentioning

confidence: 99%

xylA cloning and sequencing and biochemical characterization of xylose isomerase from Thermotoga neapolitana

Vieille

Hess

Kelly

et al. 1995

Appl Environ Microbiol

105

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Heterologous expression and biochemical characterization of glucose isomerase from Thermobifida fusca

Deng

Chen

et al. 2013

Bioprocess Biosyst Eng

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Glucose isomerase (GIase) catalyzes the isomerization of D-glucose to D-fructose. The GIase from Thermobifida fusca WSH03-11 was expressed in Escherichia coli BL21(DE3), and the purified enzyme took the form of a tetramer in solution and displayed a pI value of 5.05. The temperature optimum of GIase was 80 °C and its half life was about 2 h at 80 °C or 15 h at 70 °C. The pH optimum of GIase was 10 and the enzyme retained 95 % activity over the pH range of 5-10 after incubating at 4 °C for 24 h. Kinetic studies showed that the K m and K cat values of the enzyme are 197 mM and 1,688 min(-1), respectively. The maximum conversion yield of glucose (45 %, w/v) to fructose of the enzyme was 53 % at pH 7.5 and 70 °C. The present study provides the basis for the industrial application of recombinant T. fusca GIase in the production of high fructose syrup.

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Microbial Enzymes for the Food Industry

Fernandes

Carvalho

2017

Biotechnology of Microbial Enzymes

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Site‐directed Mutagenesis Applied to Glucose Isomerase from Streptomyces violaceoniger and Streptomyces olivochromogenes

Cited by 6 publications

References 11 publications

xylA cloning and sequencing and biochemical characterization of xylose isomerase from Thermotoga neapolitana

xylA cloning and sequencing and biochemical characterization of xylose isomerase from Thermotoga neapolitana

Heterologous expression and biochemical characterization of glucose isomerase from Thermobifida fusca

Microbial Enzymes for the Food Industry

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