1
|
Guo H, Wang H, Chen T, Guo L, Blank LM, Ebert BE, Huo YX. Engineering Critical Amino Acid Residues of Lanosterol Synthase to Improve the Production of Triterpenoids in Saccharomyces cerevisiae. ACS Synth Biol 2022; 11:2685-2696. [PMID: 35921601 DOI: 10.1021/acssynbio.2c00098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Triterpenoids are a subgroup of terpenoids and have wide applications in the food, cosmetics, and pharmaceutical industries. The heterologous production of various triterpenoids in Saccharomyces cerevisiae, as well as other microbes, has been successfully implemented as these production hosts not only produce the precursor of triterpenoids 2,3-oxidosqualene by the mevalonate pathway but also allow simple expression of plant membrane-anchored enzymes. Nevertheless, 2,3-oxidosqualene is natively converted to lanosterol catalyzed by the endogenous lanosterol synthase (Erg7p), causing low production of recombinant triterpenoids. While simple deletion of ERG7 was not effective, in this study, the critical amino acid residues of Erg7p were engineered to lower this critical enzyme activity. The engineered S. cerevisiae indeed accumulated 2,3-oxidosqualene up to 180 mg/L. Engineering triterpenoid synthesis into the ERG7-modified strain resulted in 7.3- and 3-fold increases in the titers of dammarane-type and lupane-type triterpenoids, respectively. This study presents an efficient inducer-free strategy for lowering Erg7p activity, thereby providing 2,3-oxidosqualene for the enhanced production of various triterpenoids.
Collapse
Affiliation(s)
- Hao Guo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China
| | - Huiyang Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China
| | - Tongtong Chen
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China
| | - Liwei Guo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China
| | - Lars M Blank
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University Worringer Weg 1, 52074 Aachen, Germany
| | - Birgitta E Ebert
- Australian Institute for Bioengineering and Nanotechnology The University of Queensland Cnr College Rd & Cooper Rd, St Luci a, QLD 4072, Australia
| | - Yi-Xin Huo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China
| |
Collapse
|
2
|
A conserved mechanism affecting hydride shifting and deprotonation in the synthesis of hopane triterpenes as compositions of wax in oat. Proc Natl Acad Sci U S A 2022; 119:e2118709119. [PMID: 35290128 PMCID: PMC8944845 DOI: 10.1073/pnas.2118709119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Hopanoids are a group of biologically important triterpene scaffolds found in nature, but the discovery of hopane-type triterpene synthases in plants has not been reported. We discovered two types of triterpene synthases synthesizing hopanoid skeletons from monocot and dicot plants and elucidated a mechanism involving the deprotonation at different sites by site-directed mutagenesis experiments and the quantum mechanics and molecular mechanics calculation. Our results provide a genetic element for synthesizing biologically active hopane-type triterpenoids and serve as a foundation for studying the molecular mechanisms of methyl and hydride transfer in the triterpene cyclization mechanism. Triterpenoids are biologically active metabolites synthesized from a common linear precursor catalyzed by 2,3-oxidosqualene cyclases (OSCs) to form diverse triterpenoid skeletons. OSCs corresponding to many discovered triterpene alcohols in nature have not been functionally and mechanistically characterized due to the diversity of chemical structures and complexity of the cyclization mechanism. We carried out a genome-wide investigation of OSCs from Avena strigosa and discovered two triterpene synthases, namely, AsHS1 and AsHS2, using a Nicotiana benthamiana expression system. These synthases produce hopenol B and hop-17(21)-en-3β-ol, which are components of surface wax in oat panicles and sheathes, respectively. We demonstrated that substitutions of two to three amino acid residues in AsHS1 with corresponding residues from AsHS2 allowed it to be completely converted into a hop-17(21)-en-3β-ol synthase. AsHS2 mutants with a substitution at site 410 could synthesize hopenol B alone or mixed with a side product isomotiol. The combined quantum mechanics and molecular mechanics calculation demonstrated that the side chain size of the residue at site 410 regulated the relative orientations between the hopyl C22 cation and Phe257, leading to a difference in deprotonation positions through providing or not providing cation–π interaction between the aromatic ring of F257 and the carbocation intermediate. A similar mechanism could be applied to a hopenol B synthase from a dicotyledonous plant Aquilegia. This study provided mechanistic insight into triterpenoid synthesis and discovered key amino acid residues acting on hydride transfer and a deprotonation site to differentiate between hopane-type scaffolds in diverse plant species.
Collapse
|
3
|
Genome-Wide Identification of OSC Gene Family and Potential Function in the Synthesis of Ursane- and Oleanane-Type Triterpene in Momordica charantia. Int J Mol Sci 2021; 23:ijms23010196. [PMID: 35008620 PMCID: PMC8745088 DOI: 10.3390/ijms23010196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/07/2021] [Accepted: 12/11/2021] [Indexed: 12/12/2022] Open
Abstract
The triterpenes in bitter gourd (Momordica charantia) show a variety of medicinal activities. Oxidosqualene cyclase (OSC) plays an indispensable role in the formation of triterpene skeletons during triterpene biosynthesis. In this study, we identified nine genes encoding OSCs from bitter gourd (McOSC1-9). Analyses of their expression patterns in different tissues suggested that characteristic triterpenoids may be biosynthesized in different tissues and then transported. We constructed a hairy root system in which McOSC7 overexpression led to an increased accumulation of camaldulenic acid, enoxolone, and quinovic acid. Thus, the overexpression of McOSC7 increased the active components content in bitter gourd. Our data provide an important foundation for understanding the roles of McOSCs in triterpenoid synthesis.
Collapse
|
4
|
Liu HR, Ahmad N, Lv B, Li C. Advances in production and structural derivatization of the promising molecule ursolic acid. Biotechnol J 2021; 16:e2000657. [PMID: 34096160 DOI: 10.1002/biot.202000657] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 02/05/2023]
Abstract
Ursolic acid (UA) is a ursane-type pentacyclic triterpenoid compound, naturally produced in plants via specialized metabolism and exhibits vast range of remarkable physiological activities and pharmacological manifestations. Owing to significant safety and efficacy in different medical conditions, UA may serve as a backbone to produce its derivatives with novel therapeutic functions. This review aims to provide ideas for exploring more diverse structures to improve UA pharmacological activity and increasing its biological yield to meet the industrial requirements by systematically reviewing the current research progress of UA. We first provides an overview of the pharmacological activities, acquisition methods and structural modifications of UA. Among them, we focused on the synthetic modifications of UA to yield valuable derivatives with enhanced therapeutic potential. Furthermore, harnessing the essential advances for green synthesis of UA and its derivatives by advent of metabolic engineering and synthetic biology are of great concern. In this regard, all pivotal advances for enhancing the production of UA have been discussed. In combination with the advantages of UA biosynthesis and transformation strategy, large-scale microbial production of UA is a promising platform for further exploration.
Collapse
Affiliation(s)
- Hao-Ran Liu
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Nadeem Ahmad
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Bo Lv
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Chun Li
- Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, P. R. China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China
| |
Collapse
|
5
|
Wang J, Guo Y, Yin X, Wang X, Qi X, Xue Z. Diverse triterpene skeletons are derived from the expansion and divergent evolution of 2,3-oxidosqualene cyclases in plants. Crit Rev Biochem Mol Biol 2021; 57:113-132. [PMID: 34601979 DOI: 10.1080/10409238.2021.1979458] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Triterpenoids are one of the largest groups of secondary metabolites and exhibit diverse structures, which are derived from C30 skeletons that are biosynthesized via the isoprenoid pathway by cyclization of 2,3-oxidosqualene. Triterpenoids have a wide range of biological activities, and are used in functional foods, drugs, and as industrial materials. Due to the low content levels in their native plants and limited feasibility and efficiency of chemical synthesis, heterologous biosynthesis of triterpenoids is the most promising strategy. Herein, we classified 121 triterpene alcohols/ketones according to their conformation and ring numbers, among which 51 skeletons have been experimentally characterized as the products of oxidosqualene cyclases (OSCs). Interestingly, 24 skeletons that have not been reported from nature source were generated by OSCs in heterologous expression. Comprehensive evolutionary analysis of the identified 152 OSCs from 75 species in 25 plant orders show that several pentacyclic triterpene synthases repeatedly originated in multiple plant lineages. Comparative analysis of OSC catalytic reaction revealed that stabilization of intermediate cations, steric hindrance, and conformation of active center amino acid residues are primary factors affecting triterpene formation. Optimization of OSC could be achieved by changing of side-chain orientations of key residues. Recently, methods, such as rationally design of pathways, regulation of metabolic flow, compartmentalization engineering, etc., were introduced in improving chassis for the biosynthesis of triterpenoids. We expect that extensive study of natural variation of large number of OSCs and catalytical mechanism will provide basis for production of high level of triterpenoids by application of synthetic biology strategies.
Collapse
Affiliation(s)
- Jing Wang
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China.,Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, PR China
| | - Yanhong Guo
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
| | - Xue Yin
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
| | - Xiaoning Wang
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xiaoquan Qi
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, PR China
| | - Zheyong Xue
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
| |
Collapse
|
6
|
Diao H, Chen N, Wang K, Zhang F, Wang YH, Wu R. Biosynthetic Mechanism of Lanosterol: A Completed Story. ACS Catal 2020. [DOI: 10.1021/acscatal.9b05221] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hongjuan Diao
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
| | - Nanhao Chen
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Kai Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
| | - Fan Zhang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
| | - Yong-Heng Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, People’s Republic of China
| | - Ruibo Wu
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
| |
Collapse
|
7
|
Molecular Docking and Molecular Dynamics Studies on Selective Synthesis of α-Amyrin and β-Amyrin by Oxidosqualene Cyclases from Ilex Asprella. Int J Mol Sci 2019; 20:ijms20143469. [PMID: 31311103 PMCID: PMC6678101 DOI: 10.3390/ijms20143469] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/02/2019] [Accepted: 07/02/2019] [Indexed: 11/22/2022] Open
Abstract
Amyrins are the immediate precursors of many pharmaceutically important pentacyclic triterpenoids. Although various amyrin synthases have been identified, little is known about the relationship between protein structures and the constituent and content of the products. IaAS1 and IaAS2 identified from Ilex asprella in our previous work belong to multifunctional oxidosqualene cyclases and can produce α-amyrin and β-amyrin at different ratios. More than 80% of total production of IaAS1 is α-amyrin; while IaAS2 mainly produces β-amyrin with a yield of 95%. Here, we present a molecular modeling approach to explore the underlying mechanism for selective synthesis. The structures of IaAS1 and IaAS2 were constructed by homology modeling, and were evaluated by Ramachandran Plot and Verify 3D program. The enzyme-product conformations generated by molecular docking indicated that ASP484 residue plays an important role in the catalytic process; and TRP611 residue of IaAS2 had interaction with β-amyrin through π–σ interaction. MM/GBSA binding free energy calculations and free energy decomposition after 50 ns molecular dynamics simulations were performed. The binding affinity between the main product and corresponding enzyme was higher than that of the by-product. Conserved amino acid residues such as TRP257; TYR259; PHE47; TRP534; TRP612; and TYR728 for IaAS1 (TRP257; TYR259; PHE473; TRP533; TRP611; and TYR727 for IaAS2) had strong interactions with both products. GLN450 and LYS372 had negative contribution to binding affinity between α-amyrin or β-amyrin and IaAS1. LYS372 and ARG261 had strong repulsive effects for the binding of α-amyrin with IaAS2. The importance of Lys372 and TRP612 of IaAS1, and Lys372 and TRP611 of IaAS2, for synthesizing amyrins were confirmed by site-directed mutagenesis. The different patterns of residue–product interactions is the cause for the difference in the yields of two products.
Collapse
|
8
|
Identification of Key Amino Acid Residues Determining Product Specificity of 2,3-Oxidosqualene Cyclase in Siraitia grosvenorii. Catalysts 2018. [DOI: 10.3390/catal8120577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during the initial substrate preorganization step, oxidosqualene cyclases (OSCs) are roughly segregated into a dammarenyl cation group that predominantly catalyzes triterpenoid precursor products and a protosteryl cation group which mostly generates sterol precursor products. The mechanism of conversion between two scaffolds is not well understood. Previously, we have characterized a promiscuous OSC from Siraitia grosvenorii (SgCS) that synthesizes a novel cucurbitane-type triterpene cucurbitadienol as its main product. By integration of homology modeling, molecular docking and site-directed mutagenesis, we discover that five key amino acid residues (Asp486, Cys487, Cys565, Tyr535, and His260) may be responsible for interconversions between chair–boat–chair and chair–chair–chair conformations. The discovery of euphol, dihydrolanosterol, dihydroxyeuphol and tirucallenol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into cucurbitane-type and lanostane-type skeletons, and provide a new strategy to identify key residues determining OSC specificity.
Collapse
|
9
|
Xue Z, Tan Z, Huang A, Zhou Y, Sun J, Wang X, Thimmappa RB, Stephenson MJ, Osbourn A, Qi X. Identification of key amino acid residues determining product specificity of 2,3-oxidosqualene cyclase in Oryza species. THE NEW PHYTOLOGIST 2018; 218:1076-1088. [PMID: 29528490 DOI: 10.1111/nph.15080] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/05/2018] [Indexed: 05/27/2023]
Abstract
Triterpene synthases, also known as 2,3-oxidosqualene cyclases (OSCs), synthesize diverse triterpene skeletons that form the basis of an array of functionally divergent steroids and triterpenoids. Tetracyclic and pentacyclic triterpene skeletons are synthesized via protosteryl and dammarenyl cations, respectively. The mechanism of conversion between two scaffolds is not well understood. Here, we report a promiscuous OSC from rice (Oryza sativa) (OsOS) that synthesizes a novel pentacyclic triterpene orysatinol as its main product. The OsOS gene is widely distributed in indica subspecies of cultivated rice and in wild rice accessions. Previously, we have characterized a different OSC, OsPS, a tetracyclic parkeol synthase found in japonica subspecies. Phylogenetic and protein structural analyses identified three key amino acid residues (#732, #365, #124) amongst 46 polymorphic sites that determine functional conversion between OsPS and OsOS, specifically, the chair-semi(chair)-chair and chair-boat-chair interconversions. The different orientation of a fourth amino acid residue Y257 was shown to be important for functional conversion The discovery of orysatinol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into tetra- and pentacyclic skeletons, and provide a new strategy to identify key residues determining OSC specificity.
Collapse
Affiliation(s)
- Zheyong Xue
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Zhengwei Tan
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China
| | - Ancheng Huang
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Yuan Zhou
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juncong Sun
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoning Wang
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Ramesha B Thimmappa
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Michael J Stephenson
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Anne Osbourn
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Xiaoquan Qi
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| |
Collapse
|
10
|
Hoshino T. β-Amyrin biosynthesis: catalytic mechanism and substrate recognition. Org Biomol Chem 2017; 15:2869-2891. [DOI: 10.1039/c7ob00238f] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the past five years, there have been remarkable advances in the study of β-amyrin synthase. This review outlines the catalytic mechanism and substrate recognition in β-amyrin biosynthesis, which have been attained by the site-directed mutagenesis and substrate analog experiments.
Collapse
Affiliation(s)
- Tsutomu Hoshino
- Graduate School of Science and Technology and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181
- Japan
| |
Collapse
|
11
|
Ito R, Nakada C, Hoshino T. β-Amyrin synthase from Euphorbia tirucalli L. functional analyses of the highly conserved aromatic residues Phe413, Tyr259 and Trp257 disclose the importance of the appropriate steric bulk, and cation-π and CH-π interactions for the efficient catalytic action of the polyolefin cyclization cascade. Org Biomol Chem 2016; 15:177-188. [PMID: 27942657 DOI: 10.1039/c6ob02539k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Many of the functions of the active site residues in β-amyrin synthase and its catalytic mechanism remain unclear. Herein, we examined the functions of the highly conserved Phe413, Tyr259, and Trp257 residues in the β-amyrin synthase of Euphorbia tirucalli. The site-specific mutants F413V and F413M [corrected] showed nearly the same enzymatic activities as the wild type, indicating that π-electrons are not needed for the catalytic reaction. However, the F413A [corrected] mutant yielded a large amount of the tetracyclic dammarane skeleton, with decreased production of β-amyrin. This indicates that the Phe413 [corrected] residue is located near the D-ring formation site and works to position the oxidosqualene substrate correctly within the reaction cavity. On the other hand, the major catalysis-related function of the Tyr259 and Trp257 residues is to yield their π-electrons to the cationic intermediates. The Y259F variant showed nearly equivalent activity to that of the wild type, but aliphatic mutants such as the Ala, Val, and Leu variants showed significantly decreased the activity and yielded the tetracyclic dammarane scaffold, strongly demonstrating that the Tyr259 residue stabilizes the baccharenyl secondary cation via cation-π interaction. The aliphatic variants of Trp257 exhibited remarkably decreased enzymatic activity, and lupeol was produced in a high production ratio, indicating that Trp257 stabilizes the oleanyl cation via cation-π interaction. The aromatic Phe and Tyr mutants exhibited high activities owing to their more increased π-electron density relative to that of the aliphatic mutants, but lupeol was produced in a significantly high yield besides β-amyrin. The Trp residue is likely to be responsible for the robust binding of Me-30 through CH-π interaction. The decreased π-electron density of the Phe and Tyr mutants compared to that of Trp would have resulted in the high production of lupeol.
Collapse
Affiliation(s)
- Ryousuke Ito
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan.
| | - Chika Nakada
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan.
| | - Tsutomu Hoshino
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan.
| |
Collapse
|
12
|
Hoshino T, Miyahara Y, Hanaoka M, Takahashi K, Kaneko I. β-Amyrin Biosynthesis: The Methyl-30 Group of (3S)-2,3-Oxidosqualene Is More Critical to Its Correct Folding To Generate the Pentacyclic Scaffold than the Methyl-24 Group. Chemistry 2015; 21:15769-84. [DOI: 10.1002/chem.201502389] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Indexed: 11/11/2022]
|
13
|
Hoshino T, Yamaguchi Y, Takahashi K, Ito R. β-Amyrin Biosynthesis: The Critical Role of Steric Volume at C-19 of 2,3-Oxidosqualene for Its Correct Folding To Generate the Pentacyclic Scaffold. Org Lett 2014; 16:3548-51. [DOI: 10.1021/ol501498q] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tsutomu Hoshino
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Yuki Yamaguchi
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Kazunari Takahashi
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Ryousuke Ito
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| |
Collapse
|
14
|
Ito R, Masukawa Y, Nakada C, Amari K, Nakano C, Hoshino T. β-Amyrin synthase from Euphorbia tirucalli. Steric bulk, not the π-electrons of Phe, at position 474 has a key role in affording the correct folding of the substrate to complete the normal polycyclization cascade. Org Biomol Chem 2014; 12:3836-46. [DOI: 10.1039/c4ob00064a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The importance of the steric bulk at 474 residue is described for completion of the cyclization cascade, but not the π-electrons of the Phe residue.
Collapse
Affiliation(s)
- Ryousuke Ito
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Yukari Masukawa
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Chika Nakada
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Kanako Amari
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Chiaki Nakano
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Tsutomu Hoshino
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| |
Collapse
|
15
|
Ito R, Hashimoto I, Masukawa Y, Hoshino T. Effect of Cation-π Interactions and Steric Bulk on the Catalytic Action of Oxidosqualene Cyclase: A Case Study of Phe728 of β-Amyrin Synthase fromEuphorbia tirucalli L. Chemistry 2013; 19:17150-8. [DOI: 10.1002/chem.201301917] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 08/31/2013] [Indexed: 11/06/2022]
|
16
|
Ito R, Masukawa Y, Hoshino T. Purification, kinetics, inhibitors and CD for recombinant β-amyrin synthase fromEuphorbia tirucalli L and functional analysis of the DCTA motif, which is highly conserved among oxidosqualene cyclases. FEBS J 2013; 280:1267-80. [DOI: 10.1111/febs.12119] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 12/23/2012] [Accepted: 01/01/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Ryousuke Ito
- Graduate School of Science and Technology; Niigata University; Japan
| | - Yukari Masukawa
- Graduate School of Science and Technology; Niigata University; Japan
| | | |
Collapse
|