|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Directed Evolution of Sequence-Regulating Polyhydroxyalkanoate Synthase to Synthesize a Medium-Chain-Length-Short-Chain-Length (MCL-SCL) Block Copolymer
| Title: | Directed Evolution of Sequence-Regulating Polyhydroxyalkanoate Synthase to Synthesize a Medium-Chain-Length-Short-Chain-Length (MCL-SCL) Block Copolymer |
| Authors: | Phan, Hien Thi Browse this author | | Hosoe, Yumi Browse this author | | Guex, Maureen Browse this author | | Tomoi, Masayoshi Browse this author | | Tomita, Hiroya Browse this author →KAKEN DB | | Zinn, Manfred Browse this author | | Matsumoto, Ken'ichiro Browse this author →KAKEN DB |
| Keywords: | PHA synthase | | poly(3-hydroxybutyrate) | | sequence regulation | | sequence regulation | | biodegradable plastic |
| Issue Date: | 7-Jan-2022 |
| Publisher: | American Chemical Society |
| Journal Title: | Biomacromolecules |
| Volume: | 23 |
| Issue: | 3 |
| Start Page: | 1221 |
| End Page: | 1231 |
| Publisher DOI: | 10.1021/acs.biomac.1c01480 |
| Abstract: | Sequence-regulating polyhydroxyalkanoate synthase PhaC(AR) is a chimeric enzyme comprising PhaCs from Aeromonas caviae and Ralstonia eutropha (Cupriavidus necator). It spontaneously synthesizes a short-chain-length (SCL, <= C5) block copolymer poly(2-hydroxybutyrate)-b-poly(3-hydroxybutyrate)[P(2HB)-b-P(3HB)] from a mixture of monomer substrates. In this study, directed evolution of PhaC(AR) was performed to increase its activity toward a medium-chain-length (MCL, C6-12) monomer, 3-hydroxyhexanoyl (3HHx)-coenzyme A (CoA). Random mutagenesis and selection based on P(3HB-co-3HHx) production in Escherichia coli found that beneficial mutations N149D and F314Lincrease the 3HHx fraction. The site-directed saturation mutagenesis at position 314, which is adjacent to the catalytic center C315, demonstrated that F314H synthesizes the P(3HHx) homopolymer. The F314H mutant exhibited increased activity toward 3HHx-CoA compared with the parent enzyme, whereas the activity toward 3HB-CoA decreased. The predicted tertiary structure of PhaC(AR) by AlphaFold2 provided insight into the mechanism of the beneficial mutations. In addition, this finding enabled the synthesis of a new PHA block copolymer, P(3HHx)-b-P(2HB). Solvent fractionation indicated the presence of a covalent linkage between the polymer segments. This novel MCL-SCL block copolymer considerably expands the range of the molecular design of PHA block copolymers. |
| Rights: | This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Biomacromolecules, copyright © American Chemical Society after peer review. To access the final edited and published work, see https://pubs.acs.org/articlesonrequest/AOR-QJB4FXIJJWGIKWKTEIYT. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/87620 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 冨田 宏矢
|
