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Xi S, Ban X, Kong H, Li C, Gu Z, Li Z. Conserved residues at the family and subfamily levels determine enzyme activity and substrate binding in glycoside hydrolase family 13. Int J Biol Macromol 2023; 253:126980. [PMID: 37729992 DOI: 10.1016/j.ijbiomac.2023.126980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/24/2023] [Accepted: 09/16/2023] [Indexed: 09/22/2023]
Abstract
Site-directed mutagenesis is a valuable strategy for modifying enzymes, but the lack of understanding of conserved residues regulating glycosidase function hinders enzyme design. We analyzed 1662 enzyme sequences to identify conserved amino acids in maltohexaose-forming amylase at both family and subfamily levels. Several conserved residues at the family level (G37, P45, R52, Y57, D101, V103, H106, G230, R232, D234, E264, H330, D331, and G360) were found, mutations of which resulted in reduced enzyme activity or inactivation. At the subfamily level, several conserved residues (L65, E67, F68, D111, E114, R126, R147, F154, W156, F161, G163, D165, W218H, V342, W345, and F346) were identified, which primarily facilitate substrate binding in the enzyme's active site, as shown by molecular dynamics and kinetic assays. Our findings provide critical insights into conserved residues essential for catalysis and can inform targeted enzyme design in protein engineering.
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Affiliation(s)
- Shixia Xi
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Xiaofeng Ban
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Haocun Kong
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Caiming Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Zhengbiao Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Zhaofeng Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, People's Republic of China.
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Liu M, Li Q, Liu X, Zhang P, Zhang H. Improved thermostability of type I pullulanase from Bacillus thermoliquefaciens by error-prone PCR. Enzyme Microb Technol 2023; 169:110290. [PMID: 37473696 DOI: 10.1016/j.enzmictec.2023.110290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/23/2023] [Accepted: 07/12/2023] [Indexed: 07/22/2023]
Abstract
Pullulanase (PulB) is a starch-debranching enzyme. In order to improve its catalytic performance, random mutagenesis was performed on the pullulanase gene derived from Bacillus thermoliquefaciens. Two rounds of error-prone PCR were carried out. Mutant T252S was screened in the first round of error-prone library, which had the highest catalytic activity. During the second round of mutations, mutant enzyme G250P/T252S/G253T/N255K was screened, which had further improved catalytic activity and the best thermostability. Compared with the parent enzyme, the specific activity of mutant enzyme G250P/T252S/G253T/N255K increased by 1.9 times, Km decreased by 22.7 %, kcat increased by 28.7 %, and kcat/Km increased by 68.4 %. The thermostability of the mutant enzyme improved significantly, showing that the half-life at 60 °C was extended to 7.5 h, which was 87.5 % higher than that of the parent enzyme. The mutation sites in these two rounds were concentrated in the 250-255 regions, indicating that this region was an important region affecting the catalytic activity and Thermostability. The reasons for the change of enzymtic properties was also preliminarily analyzed through three-dimensional simulation.
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Affiliation(s)
- Mengmeng Liu
- School of Life Sciences, Henan University, Kaifeng 475004, China; Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng 475004, China
| | - Qiu Li
- School of Life Sciences, Henan University, Kaifeng 475004, China; Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng 475004, China
| | - Xiaoxiao Liu
- School of Life Sciences, Henan University, Kaifeng 475004, China; Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng 475004, China
| | - Pengpai Zhang
- School of Life Sciences, Henan University, Kaifeng 475004, China; Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng 475004, China.
| | - Haiyan Zhang
- School of Life Sciences, Henan University, Kaifeng 475004, China; Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng 475004, China.
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3
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Naik B, Kumar V, Goyal SK, Dutt Tripathi A, Mishra S, Joakim Saris PE, Kumar A, Rizwanuddin S, Kumar V, Rustagi S. Pullulanase: unleashing the power of enzyme with a promising future in the food industry. Front Bioeng Biotechnol 2023; 11:1139611. [PMID: 37449089 PMCID: PMC10337586 DOI: 10.3389/fbioe.2023.1139611] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Pullulanases are the most important industrial group of enzymes in family 13 glycosyl hydrolases. They hydrolyze either α-1,6 and α-1,4 or both glycosidic bonds in pullulan as well as other carbohydrates to produce glucose, maltose, and maltotriose syrups, which have important uses in food and other related sectors. However, very less reports are available on pullulanase production from native strains because of low yield issues. In line with the increasing demands for pullulanase, it has become important to search for novel pullulanase-producing microorganisms with high yields. Moreover, high production costs and low yield are major limitations in the industrial production of pullulanase enzymes. The production cost of pullulanase by using the solid-state fermentation (SSF) process can be minimized by selecting agro-industrial waste. This review summarizes the types, sources, production strategies, and potential applications of pullulanase in different food and other related industries. Researchers should focus on fungal strains producing pullulanase for better yield and low production costs by using agro-waste. It will prove a better enzyme in different food processing industries and will surely reduce the cost of products.
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Affiliation(s)
- Bindu Naik
- Department of Food Science and Technology, Graphic Era (Deemed to be University), Uttarakhand, India
| | - Vijay Kumar
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun, India
| | - S. K. Goyal
- Department of Agricultural Engineering, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India
| | - Abhishek Dutt Tripathi
- Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India
| | - Sadhna Mishra
- Faculty of Agricultural Sciences, GLA University, Mathura, India
| | - Per Erik Joakim Saris
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Akhilesh Kumar
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun, India
| | - Sheikh Rizwanuddin
- Department of Food Science and Technology, Graphic Era (Deemed to be University), Uttarakhand, India
| | - Vivek Kumar
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun, India
| | - Sarvesh Rustagi
- Department of Food Technology, UCLAS, Uttaranchal University, Dehradun, India
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Wu Y, Huang S, Liang X, Han P, Liu Y. Characterization of a novel detergent-resistant type I pullulanase from Bacillus megaterium Y103 and its application in laundry detergent. Prep Biochem Biotechnol 2022:1-7. [PMID: 36271878 DOI: 10.1080/10826068.2022.2134890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study aims to find a moderate pullulanase for detergent industry. The pulY103B gene (2217 bp) from Bacillus megaterium Y103 was cloned and expressed in Escherichia coli. PulY103B contained four conserved regions of glycoside hydrolase family (GH) 13 and the typical sequence of type I pullulanase. The optimal reaction conditions of PulY103B were pH 6.5 and 40 °C. In addition, it remained stable below 40 °C and over 80% of activity was retained at pH ranging from 6.0 to 8.5. The best substrate for the enzyme was pullulan. Furthermore, it exhibited activity toward wheat starch (36.5%) and soluble starch (33.4%) but had no activity toward amylose and glycogen. Maltotriose and maltohexaose were major pullulan hydrolysis products. Soluble starch and amylopectin were mainly hydrolyzed into maltotetraose. These results indicated that PulY103B is a novel type I pullulanase with transglycosylation activity via formation of α-1,4-glucosidic linkages. Moreover, PulY103B was strongly stimulated by nonionic detergents [viz, Tween 20 (10%), Tween 80 (1%), Triton X-100 (20%)] and commercial liquid detergents (3.0 g/L). Wash performance tests demonstrated that the mixture of PulY103B and detergent removed starch-based stains better than using detergent alone (p < 0.05). Therefore, this pullulanase has big potential as a detergent additive.
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Affiliation(s)
- Yongmin Wu
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, China
| | - Shuai Huang
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, China
| | - Xiaobo Liang
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, China
| | - Peng Han
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, China
| | - Yuchun Liu
- Academy of National Food and Strategic Reserves Administration, Beijing, China
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Abstract
Starch and pullulan degrading enzymes are essential industrial biocatalysts. Pullulan-degrading enzymes are grouped into pullulanases (types I and type II) and pullulan hydrolase (types I, II and III). Generally, these enzymes hydrolyse the α-1,6 glucosidic bonds (and α-1,4 for certain enzyme groups) of substrates and form reducing sugars such as glucose, maltose, maltotriose, panose or isopanose. This review covers two main aspects: (i) bibliometric analysis of publications and patents related to pullulan-degrading enzymes and (ii) biological aspects of free and immobilised pullulan-degrading enzymes and protein engineering. The collective data suggest that most publications involved researchers within the same institution or country in the past and current practice. Multi-national interaction shall be improved, especially in tapping the enzymes from unculturable prokaryotes. While the understanding of pullulanases may reach a certain extend of saturation, the discovery of pullulan hydrolases is still limited. In this report, we suggest readers consider using the next-generation sequencing technique to fill the gaps of finding more new sequences encoding pullulan-degrading enzymes to expand the knowledge body of this topic.
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Microbial starch debranching enzymes: Developments and applications. Biotechnol Adv 2021; 50:107786. [PMID: 34147588 DOI: 10.1016/j.biotechadv.2021.107786] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 06/04/2021] [Accepted: 06/15/2021] [Indexed: 12/28/2022]
Abstract
Starch debranching enzymes (SDBEs) hydrolyze the α-1,6 glycosidic bonds in polysaccharides such as starch, amylopectin, pullulan and glycogen. SDBEs are also important enzymes for the preparation of sugar syrup, resistant starch and cyclodextrin. As the synergistic catalysis of SDBEs and other starch-acting hydrolases can effectively improve the raw material utilization and production efficiency during starch processing steps such as saccharification and modification, they have attracted substantial research interest in the past decades. The substrate specificities of the two major members of SDBEs, pullulanases and isoamylases, are quite different. Pullulanases generally require at least two α-1,4 linked glucose units existing on both sugar chains linked by the α-1,6 bond, while isoamylases require at least three units of α-1,4 linked glucose. SDBEs mainly belong to glycoside hydrolase (GH) family 13 and 57. Except for GH57 type II pullulanse, GH13 pullulanases and isoamylases share plenty of similarities in sequence and structure of the core catalytic domains. However, the N-terminal domains, which might be one of the determinants contributing to the substrate binding of SDBEs, are distinct in different enzymes. In order to overcome the current defects of SDBEs in catalytic efficiency, thermostability and expression level, great efforts have been made to develop effective enzyme engineering and fermentation strategies. Herein, the diverse biochemical properties and distinct features in the sequence and structure of pullulanase and isoamylase from different sources are summarized. Up-to-date developments in the enzyme engineering, heterologous production and industrial applications of SDBEs is also reviewed. Finally, research perspective which could help understanding and broadening the applications of SDBEs are provided.
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