|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Agriculture / Faculty of Agriculture >
Peer-reviewed Journal Articles, etc >
Effects of mutation of Asn694 in Aspergillus niger α-glucosidase on hydrolysis and transglucosylation
Title: | Effects of mutation of Asn694 in Aspergillus niger α-glucosidase on hydrolysis and transglucosylation |
Authors: | Ma, Min Browse this author | Okuyama, Masayuki Browse this author →KAKEN DB | Sato, Megumi Browse this author | Tagami, Takayoshi Browse this author | Klahan, Patcharapa Browse this author | Kumagai, Yuya Browse this author | Mori, Haruhide Browse this author →KAKEN DB | Kimura, Atsuo Browse this author →KAKEN DB |
Keywords: | α-Glucosidase | Transglucosylation | Isomaltooligosaccharides | Aspergillus niger | Structural element | Site-directed mutagenesis |
Issue Date: | Aug-2017 |
Publisher: | Springer |
Journal Title: | Applied microbiology and biotechnology |
Volume: | 101 |
Issue: | 16 |
Start Page: | 6399 |
End Page: | 6408 |
Publisher DOI: | 10.1007/s00253-017-8402-6 |
PMID: | 28688044 |
Abstract: | Aspergillus niger α-glucosidase (ANG), a member of glycoside hydrolase family 31, catalyzes hydrolysis of alpha-glucosidic linkages at the non-reducing end. In the presence of high concentrations of maltose, the enzyme also catalyzes the formation of α-(1 -> 6)-glucosyl products by transglucosylation and it is used for production of the industrially useful panose and isomaltooligosaccharides. The initial transglucosylation by wild-type ANG in the presence of 100 mM maltose [Glc(α 1-4)Glc] yields both α-(1 -> 6)- and α-(1 -> 4)-glucosidic linkages, the latter constituting similar to 25% of the total transfer reaction product. The maltotriose [Glc(α 1-4)Glc(α 1-4)Glc], α-(1 -> 4)-glucosyl product disappears quickly, whereas the α-(1 -> 6)-glucosyl products panose [Glc(α 1-6)Glc(α 1-4)Glc], isomaltose [Glc(α 1-6)Glc], and isomaltotriose [Glc(α 1-6)Glc(α 1-6)Glc] accumulate. To modify the transglucosylation properties of ANG, residue Asn694, which was predicted to be involved in formation of the plus subsites of ANG, was replaced with Ala, Leu, Phe, and Trp. Except for N694A, the mutations enhanced the initial velocity of the α-(1 -> 4)-transfer reaction to produce maltotriose, which was then degraded at a rate similar to that by wild-type ANG. With increasing reaction time, N694F and N694W mutations led to the accumulation of larger amounts of isomaltose and isomaltotriose than achieved with the wild-type enzyme. In the final stage of the reaction, the major product was panose (N694A and N694L) or isomaltose (N694F and N694W). |
Rights: | The final publication is available at link.springer.com via http://dx.doi.org/10.1007/s00253-017-8402-6 |
Type: | article (author version) |
URI: | http://hdl.handle.net/2115/71157 |
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)
|
Submitter: 奥山 正幸
|