Efficient biosynthesis of prunin in methanol cosolvent system by an organic solvent-tolerant α-L-rhamnosidase from Spirochaeta thermophila

• Published in: Enzyme and microbial technology 2024-04, Vol.175, p.110410-110410, Article 110410
• Main Authors: Luo, Chen-Mu, Ke, Li-Fan, Huang, Xiang-Yu, Zhuang, Xiao-Yan, Guo, Ze-Wang, Xiao, Qiong, Chen, Jun, Chen, Fu-Quan, Yang, Qiu-Ming, Ru, Yi, Weng, Hui-Fen, Xiao, An-Feng, Zhang, Yong-Hui
• Format: Article
• Language: English
• Subjects: bioactive properties; bioavailability; biosynthesis; Biotransformation; enzymes; hydrolysis; Methanol; molecular dynamics; Naringin; Prunin; simulation models; solvents; space and time; Spirochaeta thermophila; substrate specificity; technology; thermal stability; α-L-rhamnosidase
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2024.110410

Prunin of desirable bioactivity and bioavailability can be transformed from plant-derived naringin by the key enzyme α-L-rhamnosidase. However, the production was limited by unsatisfactory properties of α-L-rhamnosidase such as thermostability and organic solvent tolerance. In this study, biochemical characteristics, and hydrolysis capacity of a novel α-L-rhamnosidase from Spirochaeta thermophila (St-Rha) were investigated, which was the first characterized α-L-rhamnosidase for Spirochaeta genus. St-Rha showed a higher substrate specificity towards naringin and exhibited excellent thermostability and methanol tolerance. The Km of St-Rha in the methanol cosolvent system was decreased 7.2-fold comparing that in the aqueous phase system, while kcat/Km value of St-Rha was enhanced 9.3-fold. Meanwhile, a preliminary conformational study was implemented through comparative molecular dynamics simulation analysis to explore the mechanism underlying the methanol tolerance of St-Rha for the first time. Furthermore, the catalytic ability of St-Rha for prunin preparation in the 20% methanol cosolvent system was explored, and 200 g/L naringin was transformed into 125.5 g/L prunin for 24 h reaction with a corresponding space-time yield of 5.2 g/L/h. These results indicated that St-Rha was a novel α-L-rhamnosidase suitable for hydrolyzing naringin in the methanol cosolvent system and provided a better alternative for improving the efficient production yield of prunin. •A novel α-L-rhamnosidase from Spirochaeta thermophila was characterized.•St-Rha showed excellent thermostability and methanol tolerance.•The highest production yield of prunin was obtained using methanol cosolvent systems.•Mechanism of methanol tolerance for α-L-rhamnosidase was studied for the first time.