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Okai M, Onoue C, Tsuda R, Ishigami C, Yoshida-Mishima C, Urano N, Kato C, Ishida M. Q301P mutant of Vibrio PR protease affects activities under low-temperature and high-pressure conditions. J Biosci Bioeng 2020; 130:341-346. [PMID: 32611521 DOI: 10.1016/j.jbiosc.2020.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/19/2020] [Accepted: 05/26/2020] [Indexed: 10/24/2022]
Abstract
We characterized a protease of the M4 family from the cold-adapted Vibrio sp. Pr21 that was isolated from seawater at 320-m deep in Sagami Bay, Japan, and named it as PR protease based on the strain name Pr21. The PR protease had activities at 10-60 °C and 0.1-350 MPa, with the optimal temperature and pressure at 40 °C and 250 MPa. The mutant 10C9 (Q301P) obtained by error-prone PCR had higher activities than the wild-type enzyme at 10-60 °C, and the Q301P mutation contributed to the increase of the activity. The specific activity value of 10C9 was also higher than that of the wild-type enzyme at 0.1-200 MPa, but the specific activity ratios (1.28-1.59) of 10C9/wild-type enzyme at 50-200 MPa at 30 °C were smaller than those at 10-60 °C (1.73-4.39) at 0.1 MPa. The catalytic efficiency value of 10C9 was lower than that of the wild-type enzyme at 200 MPa. The homology models of PR protease suggested that the side chain of Q301 was hydrogen-bonded with the carbonyl oxygen atom of the main chain of N234 in the wild-type enzyme, and P301 had no contact with N234 in 10C9. The break of the hydrogen bond in 10C9 might strengthen the increase of the flexibility of the β-sheet near the substrate binding pocket under high-temperature conditions, whereas the flexibility of the β-sheet in 10C9 might be moderately increased compared to that in the wild-type enzyme under high-pressure conditions.
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Affiliation(s)
- Masahiko Okai
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Chiori Onoue
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Ryo Tsuda
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Chihiro Ishigami
- School of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Chie Yoshida-Mishima
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Naoto Urano
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Chiaki Kato
- Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa 237-0061, Japan
| | - Masami Ishida
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan.
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