Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria
Intracellular pyridoxal 5´-phosphate (PLP) -dependent recombinant phosphoserine aminotransferases (PSATs; EC 2.6.1.52) from two alkaliphilic Bacillus strains were overproduced in Escherichia coli, purified to homogeneity and their enzymological characteristics were compared to PSAT from neutralophil...
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| Format: | Article |
| Language: | English |
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De Gruyter
2020-03-01
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| Series: | Open Chemistry |
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| Online Access: | https://doi.org/10.1515/chem-2020-0014 |
| _version_ | 1818728226747318272 |
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| author | Koivulehto Marianne Battchikova Natalia Korpela Saara Khalikova Elvira Zavialov Anton Korpela Timo |
| author_facet | Koivulehto Marianne Battchikova Natalia Korpela Saara Khalikova Elvira Zavialov Anton Korpela Timo |
| author_sort | Koivulehto Marianne |
| collection | DOAJ |
| description | Intracellular pyridoxal 5´-phosphate (PLP) -dependent recombinant phosphoserine aminotransferases (PSATs; EC 2.6.1.52) from two alkaliphilic Bacillus strains were overproduced in Escherichia coli, purified to homogeneity and their enzymological characteristics were compared to PSAT from neutralophilic E. coli. Some of the enzymatic characteristics of the PSATs from the alkaliphiles were unique, showing high and sharp pH optimal of the activity related to putative internal pH inside the microbes. The specific activities of all of the studied enzymes were similar (42-44 U/mg) as measured at the pH optima of the enzymes. The spectrophotometric acid-base titration of the PLP chromophore of the enzymes from the alkaliphiles showed that the pH optimum of the activity appeared at the pH wherein the active sites were half-protonated. Detachment of PLP from holoenzymes did not take place even at pH up to 11. The kinetics of the activity loss at acid and alkaline pHs were similar in all three enzymes and followed similar kinetics. The available 3-D structural data is discussed as well as the role of protons at the active site of aminotransferases. |
| first_indexed | 2024-12-17T22:26:38Z |
| format | Article |
| id | doaj.art-cd91d18ec78a4b30ae301228f25f1ec9 |
| institution | Directory Open Access Journal |
| issn | 2391-5420 |
| language | English |
| last_indexed | 2024-12-17T22:26:38Z |
| publishDate | 2020-03-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Open Chemistry |
| spelling | doaj.art-cd91d18ec78a4b30ae301228f25f1ec92022-12-21T21:30:19ZengDe GruyterOpen Chemistry2391-54202020-03-0118114916410.1515/chem-2020-0014chem-2020-0014Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteriaKoivulehto Marianne0Battchikova Natalia1Korpela Saara2Khalikova Elvira3Zavialov Anton4Korpela Timo5International Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Tykistökatu 6A, Turku, FIN-20520, FinlandInternational Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Tykistökatu 6A, Turku, FIN-20520, FinlandInternational Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Tykistökatu 6A, Turku, FIN-20520, FinlandInternational Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Tykistökatu 6A, Turku, FIN-20520, FinlandInternational Joint Biotechnology Laboratory, MediCity, Faculty of Medicine, University of Turku, Tykistökatu 6A, Turku, FIN-20520, FinlandDepartment of Future Technologies, University of Turku, FI 20014, TurkuFinlandIntracellular pyridoxal 5´-phosphate (PLP) -dependent recombinant phosphoserine aminotransferases (PSATs; EC 2.6.1.52) from two alkaliphilic Bacillus strains were overproduced in Escherichia coli, purified to homogeneity and their enzymological characteristics were compared to PSAT from neutralophilic E. coli. Some of the enzymatic characteristics of the PSATs from the alkaliphiles were unique, showing high and sharp pH optimal of the activity related to putative internal pH inside the microbes. The specific activities of all of the studied enzymes were similar (42-44 U/mg) as measured at the pH optima of the enzymes. The spectrophotometric acid-base titration of the PLP chromophore of the enzymes from the alkaliphiles showed that the pH optimum of the activity appeared at the pH wherein the active sites were half-protonated. Detachment of PLP from holoenzymes did not take place even at pH up to 11. The kinetics of the activity loss at acid and alkaline pHs were similar in all three enzymes and followed similar kinetics. The available 3-D structural data is discussed as well as the role of protons at the active site of aminotransferases.https://doi.org/10.1515/chem-2020-0014pyridoxal 5´-phosphate dependent enzymesphosphoserine aminotransferaseprotons at the active site of transaminases |
| spellingShingle | Koivulehto Marianne Battchikova Natalia Korpela Saara Khalikova Elvira Zavialov Anton Korpela Timo Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria Open Chemistry pyridoxal 5´-phosphate dependent enzymes phosphoserine aminotransferase protons at the active site of transaminases |
| title | Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| title_full | Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| title_fullStr | Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| title_full_unstemmed | Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| title_short | Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| title_sort | comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria |
| topic | pyridoxal 5´-phosphate dependent enzymes phosphoserine aminotransferase protons at the active site of transaminases |
| url | https://doi.org/10.1515/chem-2020-0014 |
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