N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity
GbIspH1, IspH type 1 in Ginkgo biloba chloroplast, is the Fe/S enzyme catalyzing the reductive dehydroxylation of HMBPP to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) at the final step of methylerythritol phosphate pathway in chloroplast. Compared to the bacterial IspH, plant...
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Wiley
2015-01-01
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| Series: | Bioinorganic Chemistry and Applications |
| Online Access: | http://dx.doi.org/10.1155/2015/241479 |
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| author | Bok-Kyu Shin Joong-Hoon Ahn Jaehong Han |
| author_facet | Bok-Kyu Shin Joong-Hoon Ahn Jaehong Han |
| author_sort | Bok-Kyu Shin |
| collection | DOAJ |
| description | GbIspH1, IspH type 1 in Ginkgo biloba chloroplast, is the Fe/S enzyme catalyzing the reductive dehydroxylation of HMBPP to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) at the final step of methylerythritol phosphate pathway in chloroplast. Compared to the bacterial IspH, plant IspH, including GbIspH1, has an additional polypeptide chain at the N-terminus. Here, biochemical function of the N-terminal region of GbIspH1 was investigated with the N-terminal truncated GbIspH1 (GbIspH1-truncated). Both wild type GbIspH1 (GbIspH1-full) and GbIspH1-truncated were catalytically active and produced IPP and DMAPP in a ratio of 15 : 1. Kinetic parameters of KM (17.3 ± 1.9 and 14.9 ± 2.3 µM) and kcat (369 ± 10 and 347 ± 12 min−1) at pH 8.0 were obtained for GbIspH1-full and GbIspH1-truncated, respectively. Interestingly, GbIspH1-full and GbIspH1-truncated showed significantly different pH-dependent activities, and the maximum enzyme activities were obtained at pH 8.0 and 7.5, respectively. However, catalytic activation energies (Ea) of GbIspH1-full and GbIspH1-truncated were almost the same with 36.5 ± 1.6 and 35.0 ± 1.9 kJ/mol, respectively. It was suggested that the N-terminal region of GbIspH1 is involved in the pH-dependent regulation of enzyme activity during photosynthesis. |
| format | Article |
| id | doaj-art-44593554b4f24f7085a056ed4a425ca6 |
| institution | Kabale University |
| issn | 1565-3633 1687-479X |
| language | English |
| publishDate | 2015-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Bioinorganic Chemistry and Applications |
| spelling | doaj-art-44593554b4f24f7085a056ed4a425ca62025-02-03T06:01:24ZengWileyBioinorganic Chemistry and Applications1565-36331687-479X2015-01-01201510.1155/2015/241479241479N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme ActivityBok-Kyu Shin0Joong-Hoon Ahn1Jaehong Han2Metalloenzyme Research Group and Department of Biotechnology, Chung-Ang University, Anseong 456-756, Republic of KoreaDepartment of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of KoreaMetalloenzyme Research Group and Department of Biotechnology, Chung-Ang University, Anseong 456-756, Republic of KoreaGbIspH1, IspH type 1 in Ginkgo biloba chloroplast, is the Fe/S enzyme catalyzing the reductive dehydroxylation of HMBPP to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) at the final step of methylerythritol phosphate pathway in chloroplast. Compared to the bacterial IspH, plant IspH, including GbIspH1, has an additional polypeptide chain at the N-terminus. Here, biochemical function of the N-terminal region of GbIspH1 was investigated with the N-terminal truncated GbIspH1 (GbIspH1-truncated). Both wild type GbIspH1 (GbIspH1-full) and GbIspH1-truncated were catalytically active and produced IPP and DMAPP in a ratio of 15 : 1. Kinetic parameters of KM (17.3 ± 1.9 and 14.9 ± 2.3 µM) and kcat (369 ± 10 and 347 ± 12 min−1) at pH 8.0 were obtained for GbIspH1-full and GbIspH1-truncated, respectively. Interestingly, GbIspH1-full and GbIspH1-truncated showed significantly different pH-dependent activities, and the maximum enzyme activities were obtained at pH 8.0 and 7.5, respectively. However, catalytic activation energies (Ea) of GbIspH1-full and GbIspH1-truncated were almost the same with 36.5 ± 1.6 and 35.0 ± 1.9 kJ/mol, respectively. It was suggested that the N-terminal region of GbIspH1 is involved in the pH-dependent regulation of enzyme activity during photosynthesis.http://dx.doi.org/10.1155/2015/241479 |
| spellingShingle | Bok-Kyu Shin Joong-Hoon Ahn Jaehong Han N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity Bioinorganic Chemistry and Applications |
| title | N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity |
| title_full | N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity |
| title_fullStr | N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity |
| title_full_unstemmed | N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity |
| title_short | N-Terminal Region of GbIspH1, Ginkgo biloba IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity |
| title_sort | n terminal region of gbisph1 ginkgo biloba isph type 1 may be involved in the ph dependent regulation of enzyme activity |
| url | http://dx.doi.org/10.1155/2015/241479 |
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