Improving the catalytic behaviors of Lactobacillus-derived fructansucrases by truncation strategies

Dawei Ni; Onur Kırtel; Dejing Yin; Wei Xu; Qiuming Chen; Ebru Toksoy Öner; Wanmeng Mu

doi:10.1016/j.enzmictec.2021.109857

Improving the catalytic behaviors of Lactobacillus-derived fructansucrases by truncation strategies

Enzyme Microb Technol. 2021 Sep:149:109857. doi: 10.1016/j.enzmictec.2021.109857. Epub 2021 Jun 24.

Authors

Dawei Ni¹, Onur Kırtel², Dejing Yin³, Wei Xu¹, Qiuming Chen¹, Ebru Toksoy Öner², Wanmeng Mu⁴

Affiliations

¹ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
² IBSB-Industrial Biotechnology and Systems Biology Research Group, Department of Bioengineering, Marmara University, Göztepe Campus, Istanbul, Turkey.
³ Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China.
⁴ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu, 214122, China. Electronic address: wmmu@jiangnan.edu.cn.

PMID: 34311894
DOI: 10.1016/j.enzmictec.2021.109857

Abstract

Fructansucrases (FSs), including inulosucrase (IS) and levansucrase (LS), are the members of the Glycoside Hydrolase family 68 (GH68) enzymes. IS and LS catalyze the polymerization of the fructosyl moiety from sucrose to inulin- and levan-type fructans, respectively. Lactobacillus-derived FSs have relatively extended N- and C-terminal sequences. However, the functional roles of these sequences in their enzymatic properties and fructan biosynthesis remain largely unknown. Limosilactobacillus reuteri (basionym: Lactobacillus reuteri) 121 could produce both IS and LS, abbreviated as Lare121-IS and Lare121-LS, respectively. In this study, it was found that the terminal truncation displayed an obvious effect on their activities and the N-terminal truncated variants, Lare121-ISΔ177-701 and Lare121-LSΔ154-686, displayed the highest activities. Melting temperature (T_m) and the thermostability at 50 °C were measured to evaluate the stability of various truncated versions, revealing the different effects of N-terminal on the stability. The average molecular weight and polymerization degree of the fructans produced by different truncated variants did not change considerably, indicating that N-terminal truncation had low influence on fructan biosynthesis. In addition, it was found that N-terminal truncation could also improve the activity of other reported FSs from Lactobacillus species.

Keywords: Inulosucrase; Lactobacillus reuteri; Levansucrase; Terminal truncation.

MeSH terms

Catalysis
Lactobacillus* / genetics
Limosilactobacillus reuteri* / genetics
Molecular Weight
Sucrose

Substances

Sucrose