| 研究実績の概要 |
Efficient plant biomass decomposition requires novel biomass-degrading enzymes, which might possess multi-substrate functions and high specific activities. To develop new enzyme cocktails for efficient plant biomass and kelp biomass decomposition, I have focused on multifunctional endoglucanases, Glycoside hydrolase 5 family (GH5), and Glycoside hydrolase 55 family (GH55), respectively.
GH5 hydrolyzes various types of polysaccharides. Our studies and others suggested that some of the subfamilies of this enzyme class are capable of hydrolyzing different polysaccharides such as cellulose, xylan, mannnan by one catalytic domain. These "multifunctional" enzymes were distributed in the GH5 subfamily 4 (GH5_4). To determine their biochemical functions, we extracted all of the available GH5_4 sequences), synthesize genes and enzymes for following assays (Glasgow et al., 2019). Furthermore, we were able to determine around ten crystal structures of those enzymes, and results are under preparation for publication.
GH55 can hydrolyze laminarin found in brown kelp. Brown kelp is consists of laminarin, alginate, mannitol, and fucoidan, and I found previously the bacterial GH55 (SactELam55A) that can decompose laminarin into glucose, gentiobiose, and laminaribiose. I decided to utilize the SactELam55A with different polysaccharide lyases, PL18s, that can hydrolyze alginate polymers. From this research, we were able to determine the synergy of two enzymes, and a combination of SactELam55A and CaPL18 resulted in the highest reactivity to the kelp (in preparation for publication).
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