キムラ　マサヒロ   木村　将大    所属   応用生物学部 応用生物学科    職種   助教
言語種別	英語
発行・発表の年月	2016/11
形態種別	学術論文
査読	査読あり
標題	Acidic mammalian chitinase is a proteases-resistant glycosidase in mouse digestive system.
執筆形態	共著
掲載誌名	Sci Rep
掲載区分	国外
出版社・発行元	Springer Nature
巻・号・頁	6,pp.67756
担当区分	筆頭著者
著者・共著者	Ohno, M., Kimura, M. (equal contribution), Miyazaki, H., Okawa, K., Onuki, R., Nemoto, C., Tabata, E,. Wakita, S., Kashimura, A., Sakaguchi, M,. Sugahara, Y,. Nukina, N,. Bauer, P.O. and Oyama, F.
概要	Chitinases are enzymes that hydrolyze chitin, a polymer of β-1, 4-linked N-acetyl-D-glucosamine (GlcNAc). Chitin has long been considered as a source of dietary fiber that is not digested in the mammalian digestive system. Here, we provide evidence that acidic mammalian chitinase (AMCase) can function as a major digestive enzyme that constitutively degrades chitin substrates and produces (GlcNAc)2 fragments in the mouse gastrointestinal environment. AMCase was resistant to endogenous pepsin C digestion and remained active in the mouse stomach extract at pH 2.0. The AMCase mRNA levels were much higher than those of four major gastric proteins and two housekeeping genes and comparable to the level of pepsinogen C in the mouse stomach tissues. Furthermore, AMCase was expressed in the gastric pepsinogen-synthesizing chief cells. The enzyme was also stable and active in the presence of trypsin and chymotrypsin at pH 7.6, where pepsin C was completely degraded. Mouse AMCase degraded polymeric colloidal and crystalline chitin substrates in the gastrointestinal environments in presence of the proteolytic enzymes. Thus, AMCase can function as a protease-resistant major glycosidase under the conditions of stomach and intestine and degrade chitin substrates to produce (GlcNAc)2, a source of carbon, nitrogen and energy.
外部リンクURL	https://www.nature.com/articles/srep37756