A novel thermophilic exochitinase ChiEn3 from Coprinopsis cinerea exhibits a hyperhydrolytic activity toward 85% deacetylated chitosan and a significant application to preparation of chitooligosaccharides from the chitosan. (1st March 2019)

• Record Type: Journal Article
• Authors: Zhou, Jiangsheng; Dai, Rujuan; Wang, Yanxin; Li, Maomao; Zhu, Yiting; Chen, Lingling; Kang, Liqin; Liu, Zhonghua; Yang, Yao; Yuan, Sheng
• Is Part Of: Carbohydrate polymers. Volume 207(2019)
• Page Start: 729
• Page End: 736
• Publication Date: 2019-03-01
• Subjects: Exochitinase -- Thermophilicity -- 85% deacetylated chitosan -- Chitooligosaccharides -- Anti-oxidant activity; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2018.12.047
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: ChiEn3 was an exochitinase with a processive mode of action. ChiEn3 hydrolyzed only soluble chitin (not insoluble chitin substrates). ChiEn3 showed hyperhydrolytic activity toward 85% deacetylated chitosan. ChiEn3-digested products of 85% deacetylated chitosan had high antioxidant activity. ChiEn3 showed remarkable thermophilicity. Abstract: ChiEn3 from Coprinopsis cinerea was characterized as an exo-acting chitinase with a processivity. ChiEn3 hydrolyzed only soluble chitin and exhibited a hyperhydrolytic activity toward 85% deacetylated chitosan which was 33.6-fold higher than its hydrolytic activity toward glycol chitin. Its maximum hydrolytic activity was observed at 60 °C and retained 66.2% of hydrolytic activity after 60 min incubation at 60 °C. Commercial 85% deacetylated chitosan was degraded by ChiEn3 to a series of COSs with a DP of 2–20 in which COSs with a DP of 3–6 were dominant, whereas, lab-prepared chitosan (FA = 0.65) was degraded by ChiEn3 to COSs with a DP of 2–10 in which the AA dimer was dominant. DPPH-radical-scavenging activity of ChiEn3-digested products of 85% deacetylated chitosan was 3.32-fold higher than that of undigested 85% deacetylated chitosan. Therefore, ChiEn3 shows a valuable advantage for application to the preparation of COSs from commercial 85% deacetylated chitosan.