TY - JOUR
T1 - Purification and characterization of a highly thermostable, oxygen-resistant, respiratory [NiFe]-hydrogenase from a marine, aerobic hydrogen-oxidizing bacterium Hydrogenovibrio marinus
AU - Yoon, Ki Seok
AU - Fukuda, Keiichi
AU - Fujisawa, Kiyoshi
AU - Nishihara, Hirofumi
N1 - Funding Information:
This study was conducted as a part of the Project for Development of a Technological Infrastructure for Industrial Bioprocesses on R&D of New Industrial Science and Technology Frontiers by the Ministry of Economy, Trade and Industry (METI), and entrusted by the New Energy and Industrial Technology Development Organization (NEDO). This work was partially supported by a Grant-in-Aid for Scientific Research (C) ( 20580094 ).
PY - 2011/6
Y1 - 2011/6
N2 - The membrane-bound [NiFe]-hydrogenase from Hydrogenovibrio marinus (HmMBH) was purified homogeneously under anaerobic conditions. Its molecular weight was estimated as 110 kDa, consisting of a heterodimeric structure of 66 kDa and 37 kDa subunits. The purified enzyme exhibited high activity in a wide temperature range: 185 U/mg at 30 °C and 615 U/mg at 85 °C (the optimum temperature). The Km and kcat/Km values for H2 were, respectively, 12 μM and 8.58 × 107 M-1 s-1. The optimum reaction pH was 7.8, but its stability was particularly high at pH 4.0-7.0. Results show that HmMBH was remarkably thermostable and oxygen-resistant: its half-life was 75 h at 80 °C under H2, and more than 72 h at 4 °C under air. The air-oxidized HmMBH for 72 h showed only weak EPR signals of Ni-B, suggesting a structural feature in which the active center is not easily oxidized.
AB - The membrane-bound [NiFe]-hydrogenase from Hydrogenovibrio marinus (HmMBH) was purified homogeneously under anaerobic conditions. Its molecular weight was estimated as 110 kDa, consisting of a heterodimeric structure of 66 kDa and 37 kDa subunits. The purified enzyme exhibited high activity in a wide temperature range: 185 U/mg at 30 °C and 615 U/mg at 85 °C (the optimum temperature). The Km and kcat/Km values for H2 were, respectively, 12 μM and 8.58 × 107 M-1 s-1. The optimum reaction pH was 7.8, but its stability was particularly high at pH 4.0-7.0. Results show that HmMBH was remarkably thermostable and oxygen-resistant: its half-life was 75 h at 80 °C under H2, and more than 72 h at 4 °C under air. The air-oxidized HmMBH for 72 h showed only weak EPR signals of Ni-B, suggesting a structural feature in which the active center is not easily oxidized.
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U2 - 10.1016/j.ijhydene.2011.03.049
DO - 10.1016/j.ijhydene.2011.03.049
M3 - Article
AN - SCOPUS:79955893150
VL - 36
SP - 7081
EP - 7088
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
SN - 0360-3199
IS - 12
ER -
