TY  - JOUR
AU  - Davis, Reeta
AU  - Molloy, Susan
AU  - Quigley, Blathnaid
AU  - Nikodinović-Runić, Jasmina
AU  - Solano, Francisco
AU  - O'Connor, Kevin 
PY  - 2018
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/1175
AB  - We evaluated the kinetic characteristics of wild type (WT) and three engineered variants (RVC10, RV145, and C10_N322S) of tyrosinase from Ralstonia solanacearum and their potential as biocatalysts to produce halogenated catechols. RV145 exhibited a 3.6- to 14.5-fold improvement in catalytic efficiency (k (cat)/K (m)) with both reductions in K (m) and increases in k (cat) compared to WT, making it the best R. solanacearum tyrosinase variant towards halogenated phenols. RVC10 also exhibited increases in catalytic efficiency with all the tested phenols. A single-mutation variant (C10_N322S) exhibited the greatest improvement in k (cat) but lowest improvement in catalytic efficiency due to an increase in K (m) compared to WT. Consistent with kinetic characteristics, biotransformation experiments showed that RV145 was a superior biocatalyst in comparison to WT. To prevent through conversion of the catechol to quinone, ascorbic acid (AA) was added to the biotransformation medium in 1:2 (substrate:AA) ratio resulting in a catechol yield of  gt  90%. Flask experiments with 10 mM 4-iodophenol and 10 mu g/mL of the RV145 enzyme yielded 9.5 mM 4-iodocatechol in the presence of 20 mM AA in 30 min. Similarly, 10 mM 4-fluorophenol was completely consumed by 20 mu g/mL of RV145 enzyme and yielded 9.2 mM 4-fluorocatechol in the presence of 20 mM AA in 80 min. The biotransformation of 20 mM 4-fluorphenol was incomplete (93%) and the yield of 4-flurocatechol was 87.5%. The 4-halophenol conversion rates and product yields obtained in this study are the highest reported using tyrosinase or any other enzyme.
PB  - Springer, New York
T2  - Applied Microbiology and Biotechnology
T1  - Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols
EP  - 5131
IS  - 12
SP  - 5121
VL  - 102
DO  - 10.1007/s00253-018-8994-5
ER  - 

@article{
author = "Davis, Reeta and Molloy, Susan and Quigley, Blathnaid and Nikodinović-Runić, Jasmina and Solano, Francisco and O'Connor, Kevin ",
year = "2018",
abstract = "We evaluated the kinetic characteristics of wild type (WT) and three engineered variants (RVC10, RV145, and C10_N322S) of tyrosinase from Ralstonia solanacearum and their potential as biocatalysts to produce halogenated catechols. RV145 exhibited a 3.6- to 14.5-fold improvement in catalytic efficiency (k (cat)/K (m)) with both reductions in K (m) and increases in k (cat) compared to WT, making it the best R. solanacearum tyrosinase variant towards halogenated phenols. RVC10 also exhibited increases in catalytic efficiency with all the tested phenols. A single-mutation variant (C10_N322S) exhibited the greatest improvement in k (cat) but lowest improvement in catalytic efficiency due to an increase in K (m) compared to WT. Consistent with kinetic characteristics, biotransformation experiments showed that RV145 was a superior biocatalyst in comparison to WT. To prevent through conversion of the catechol to quinone, ascorbic acid (AA) was added to the biotransformation medium in 1:2 (substrate:AA) ratio resulting in a catechol yield of  gt  90%. Flask experiments with 10 mM 4-iodophenol and 10 mu g/mL of the RV145 enzyme yielded 9.5 mM 4-iodocatechol in the presence of 20 mM AA in 30 min. Similarly, 10 mM 4-fluorophenol was completely consumed by 20 mu g/mL of RV145 enzyme and yielded 9.2 mM 4-fluorocatechol in the presence of 20 mM AA in 80 min. The biotransformation of 20 mM 4-fluorphenol was incomplete (93%) and the yield of 4-flurocatechol was 87.5%. The 4-halophenol conversion rates and product yields obtained in this study are the highest reported using tyrosinase or any other enzyme.",
publisher = "Springer, New York",
journal = "Applied Microbiology and Biotechnology",
title = "Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols",
pages = "5131-5121",
number = "12",
volume = "102",
doi = "10.1007/s00253-018-8994-5"
}

Davis, R., Molloy, S., Quigley, B., Nikodinović-Runić, J., Solano, F.,& O'Connor, K.. (2018). Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols. in Applied Microbiology and Biotechnology
Springer, New York., 102(12), 5121-5131.
https://doi.org/10.1007/s00253-018-8994-5

Davis R, Molloy S, Quigley B, Nikodinović-Runić J, Solano F, O'Connor K. Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols. in Applied Microbiology and Biotechnology. 2018;102(12):5121-5131.
doi:10.1007/s00253-018-8994-5 .

Davis, Reeta, Molloy, Susan, Quigley, Blathnaid, Nikodinović-Runić, Jasmina, Solano, Francisco, O'Connor, Kevin , "Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols" in Applied Microbiology and Biotechnology, 102, no. 12 (2018):5121-5131,
https://doi.org/10.1007/s00253-018-8994-5 . .

TY  - JOUR
AU  - Molloy, Susan
AU  - Nikodinović-Runić, Jasmina
AU  - Martin, Leona B.
AU  - Hartmann, Hermann
AU  - Solano, Francisco
AU  - Decker, Heinz
AU  - O'Connor, Kevin 
PY  - 2013
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/646
AB  - The tyrosinase gene from Ralstonia solanacearum (GenBank NP518458) was subjected to random mutagenesis resulting in tyrosinase variants (RVC10 and RV145) with up to 3.2-fold improvement in kcat, 5.2-fold lower Km and 16-fold improvement in catalytic efficiency for D-tyrosine. Based on RVC10 and RV145 mutated sequences, single mutation variants were generated with all variants showing increased kcat for D-tyrosine compared to the wild type (WT). All single mutation variants based on RV145 had a higher kcat and Km value compared to the RV145 and thus the combination of four mutations in RV145 was antagonistic for turnover, but synergistic for affinity of the enzyme for D-tyrosine. Single mutation variant 145_V153A exhibited the highest (6.9-fold) improvement in kcat and a 2.4-fold increase in Km compared to the WT. Two single mutation variants, C10_N322S and C10_T183I reduced the Km up to 2.6-fold for D-tyrosine but one variant 145_V153A increased the Km 2.4-fold compared to the WT. Homology based modeling of R. solanacearum tyrosinase showed that mutation V153A disrupts the van der Waals interactions with an -helix providing one of the conserved histidine residues of the active site. The kcat and Km values for L-tyrosine decreased for RV145 and RVC10 compared to the WT. RV145 exhibited a 2.1-fold high catalytic efficiency compared to the WT which is a 7.6-fold lower improvement compared to D-tyrosine. RV145 exhibited a threefold higher monophenolase:diphenolase activity ratio for D-tyrosine:D-DOPA and a 1.4-fold higher L-tyrosine:L-DOPA activity ratio compared to the WT. Biotechnol. Bioeng. 2013; 110: 1849-1857.
PB  - Wiley, Hoboken
T2  - Biotechnology and Bioengineering
T1  - Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D-tyrosine using random and site directed mutagenesis approaches
EP  - 1857
IS  - 7
SP  - 1849
VL  - 110
DO  - 10.1002/bit.24859
ER  - 

@article{
author = "Molloy, Susan and Nikodinović-Runić, Jasmina and Martin, Leona B. and Hartmann, Hermann and Solano, Francisco and Decker, Heinz and O'Connor, Kevin ",
year = "2013",
abstract = "The tyrosinase gene from Ralstonia solanacearum (GenBank NP518458) was subjected to random mutagenesis resulting in tyrosinase variants (RVC10 and RV145) with up to 3.2-fold improvement in kcat, 5.2-fold lower Km and 16-fold improvement in catalytic efficiency for D-tyrosine. Based on RVC10 and RV145 mutated sequences, single mutation variants were generated with all variants showing increased kcat for D-tyrosine compared to the wild type (WT). All single mutation variants based on RV145 had a higher kcat and Km value compared to the RV145 and thus the combination of four mutations in RV145 was antagonistic for turnover, but synergistic for affinity of the enzyme for D-tyrosine. Single mutation variant 145_V153A exhibited the highest (6.9-fold) improvement in kcat and a 2.4-fold increase in Km compared to the WT. Two single mutation variants, C10_N322S and C10_T183I reduced the Km up to 2.6-fold for D-tyrosine but one variant 145_V153A increased the Km 2.4-fold compared to the WT. Homology based modeling of R. solanacearum tyrosinase showed that mutation V153A disrupts the van der Waals interactions with an -helix providing one of the conserved histidine residues of the active site. The kcat and Km values for L-tyrosine decreased for RV145 and RVC10 compared to the WT. RV145 exhibited a 2.1-fold high catalytic efficiency compared to the WT which is a 7.6-fold lower improvement compared to D-tyrosine. RV145 exhibited a threefold higher monophenolase:diphenolase activity ratio for D-tyrosine:D-DOPA and a 1.4-fold higher L-tyrosine:L-DOPA activity ratio compared to the WT. Biotechnol. Bioeng. 2013; 110: 1849-1857.",
publisher = "Wiley, Hoboken",
journal = "Biotechnology and Bioengineering",
title = "Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D-tyrosine using random and site directed mutagenesis approaches",
pages = "1857-1849",
number = "7",
volume = "110",
doi = "10.1002/bit.24859"
}

Molloy, S., Nikodinović-Runić, J., Martin, L. B., Hartmann, H., Solano, F., Decker, H.,& O'Connor, K.. (2013). Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D-tyrosine using random and site directed mutagenesis approaches. in Biotechnology and Bioengineering
Wiley, Hoboken., 110(7), 1849-1857.
https://doi.org/10.1002/bit.24859

Molloy S, Nikodinović-Runić J, Martin LB, Hartmann H, Solano F, Decker H, O'Connor K. Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D-tyrosine using random and site directed mutagenesis approaches. in Biotechnology and Bioengineering. 2013;110(7):1849-1857.
doi:10.1002/bit.24859 .

Molloy, Susan, Nikodinović-Runić, Jasmina, Martin, Leona B., Hartmann, Hermann, Solano, Francisco, Decker, Heinz, O'Connor, Kevin , "Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D-tyrosine using random and site directed mutagenesis approaches" in Biotechnology and Bioengineering, 110, no. 7 (2013):1849-1857,
https://doi.org/10.1002/bit.24859 . .