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Truncation of N- and C-terminal regions of Streptococcus mutans dextranase enhances catalytic activity.
Title: | Truncation of N- and C-terminal regions of Streptococcus mutans dextranase enhances catalytic activity. |
Authors: | Kim, Young-Min Browse this author | Shimizu, Ryoko Browse this author | Nakai, Hiroyuki Browse this author | Mori, Haruhide Browse this author | Okuyama, Masayuki Browse this author | Kang, Min-Sun Browse this author | Fujimoto, Zui Browse this author | Funane, Kazumi Browse this author | Kim, Doman Browse this author | Kimura, Atsuo Browse this author →KAKEN DB |
Keywords: | endo-dextranase | glycoside hydrolase family 66 | limited proteolysis | truncation |
Issue Date: | Jul-2011 |
Publisher: | springer |
Journal Title: | Applied microbiology and biotechnology |
Volume: | 91 |
Issue: | 2 |
Start Page: | 329 |
End Page: | 339 |
Publisher DOI: | 10.1007/s00253-011-3201-y |
PMID: | 21479716 |
Abstract: | Multiple forms of native and recombinant endo-dextranases (Dexs) of the glycoside hydrolase family (GH) 66 exist. The GH 66 Dex gene from Streptococcus mutans ATCC 25175 (SmDex) was expressed in Escherichia coli. The recombinant full-size (95.4 kDa) SmDex protein was digested to form an 89.8 kDa isoform (SmDex90). The purified SmDex90 was proteolytically degraded to more than seven polypeptides (23-70 kDa) during long storage. The protease-insensitive protein was desirable for the biochemical analysis and utilization of SmDex. GH 66 Dex was predicted to comprise four regions from the N- to C-termini: N-terminal variable region (N-VR), conserved region (CR), glucan-binding site (GBS), and C-terminal variable region (C-VR). Five truncated SmDexs were generated by deleting N-VR, GBS, and/or C-VR. Two truncation-mutant enzymes devoid of C-VR (TM-NCGΔ) or N-VR/C-VR (TM-ΔCGΔ) were catalytically active, thereby indicating that N-VR and C-VR were not essential for the catalytic activity. TM-ΔCGΔ did not accept any further protease-degradation during long storage. TM-NCGΔ and TM-ΔCGΔ enhanced substrate hydrolysis, suggesting that N-VR and C-VR induce hindered substrate binding to the active site. |
Type: | article (author version) |
URI: | http://hdl.handle.net/2115/48315 |
Appears in Collections: | 農学院・農学研究院 (Graduate School of Agriculture / Faculty of Agriculture) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 木村 淳夫
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