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Ganjoo A, Babu V. Recombinant Amidases: Recent Insights and its Applications in the Production of Industrially Important Fine Chemicals. Mol Biotechnol 2024:10.1007/s12033-024-01123-8. [PMID: 38598092 DOI: 10.1007/s12033-024-01123-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/27/2024] [Indexed: 04/11/2024]
Abstract
The current research for the synthesis of industrially important fine chemicals is more inclined towards developing enzyme-based processes. The biotransformation reactions wherein microbial cells/enzymes are used, have become essential in making the process efficient, green, and economical. Amongst industrially important enzymes, amidase is one of the most versatile tools in biocatalysis and biotransformation reactions. It shows broad substrate specificity and sturdy functional characteristics because of its promiscuous nature. Further, advancement in the area led to the development of amidase recombinant systems, which are developed using biotechnology and enzyme engineering tools. Additionally, recombinant amidases may be instrumental in commercializing the synthesis of fine chemicals such as hydroxamic acids that have a significant pharmaceutical market. Hence, the present review focuses on highlighting and assimilating the tools and techniques used in developing recombinant systems followed by their applications.
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Affiliation(s)
- Ananta Ganjoo
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu & Kashmir, 180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Vikash Babu
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu & Kashmir, 180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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Miri S, Yeo J, Abubaker S, Hammami R. Neuromicrobiology, an emerging neurometabolic facet of the gut microbiome? Front Microbiol 2023; 14:1098412. [PMID: 36733917 PMCID: PMC9886687 DOI: 10.3389/fmicb.2023.1098412] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/03/2023] [Indexed: 01/18/2023] Open
Abstract
The concept of the gut microbiome is emerging as a metabolic interactome influenced by diet, xenobiotics, genetics, and other environmental factors that affect the host's absorption of nutrients, metabolism, and immune system. Beyond nutrient digestion and production, the gut microbiome also functions as personalized polypharmacy, where bioactive metabolites that our microbes excrete or conjugate may reach systemic circulation and impact all organs, including the brain. Appreciable evidence shows that gut microbiota produce diverse neuroactive metabolites, particularly neurotransmitters (and their precursors), stimulating the local nervous system (i.e., enteric and vagus nerves) and affecting brain function and cognition. Several studies have demonstrated correlations between the gut microbiome and the central nervous system sparking an exciting new research field, neuromicrobiology. Microbiome-targeted interventions are seen as promising adjunctive treatments (pre-, pro-, post-, and synbiotics), but the mechanisms underlying host-microbiome interactions have yet to be established, thus preventing informed evidence-based therapeutic applications. In this paper, we review the current state of knowledge for each of the major classes of microbial neuroactive metabolites, emphasizing their biological effects on the microbiome, gut environment, and brain. Also, we discuss the biosynthesis, absorption, and transport of gut microbiota-derived neuroactive metabolites to the brain and their implication in mental disorders.
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Affiliation(s)
- Saba Miri
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - JuDong Yeo
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Sarah Abubaker
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Riadh Hammami
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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Wu Z, Liu C, Zhang Z, Zheng R, Zheng Y. Amidase as a versatile tool in amide-bond cleavage: From molecular features to biotechnological applications. Biotechnol Adv 2020; 43:107574. [PMID: 32512219 DOI: 10.1016/j.biotechadv.2020.107574] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/31/2020] [Accepted: 06/01/2020] [Indexed: 12/27/2022]
Abstract
Amidases (EC 3. 5. 1. X) are versatile biocatalysts for synthesis of chiral carboxylic acids, α-amino acids and amides due to their hydrolytic and acyl transfer activity towards the C-N linkages. They have been extensively exploited and studied during the past years for their high specific activity and excellent enantioselectivity involved in various biotechnological applications in pharmaceutical and agrochemical industries. Additionally, they have attracted considerable attentions in biodegradation and bioremediation owing to environmental pressures. Motivated by industrial demands, crystallographic investigations and catalytic mechanisms of amidases based on structural biology have witnessed a dramatic promotion in the last two decades. The protein structures showed that different types of amidases have their typical stuctural elements, such as the conserved AS domains in signature amidases and the typical architecture of metal-associated active sites in acetamidase/formamidase family amidases. This review provides an overview of recent research advances in various amidases, with a focus on their structural basis of phylogenetics, substrate specificities and catalytic mechanisms as well as their biotechnological applications. As more crystal structures of amidases are determined, the structure/function relationships of these enzymes will also be further elucidated, which will facilitate molecular engineering and design of amidases to meet industrial requirements.
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Affiliation(s)
- Zheming Wu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Changfeng Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Zhaoyu Zhang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Renchao Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
| | - Yuguo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China; The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
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An X, Cheng Y, Miao L, Chen X, Zang H, Li C. Characterization and genome functional analysis of an efficient nitrile-degrading bacterium, Rhodococcus rhodochrous BX2, to lay the foundation for potential bioaugmentation for remediation of nitrile-contaminated environments. JOURNAL OF HAZARDOUS MATERIALS 2020; 389:121906. [PMID: 31874764 DOI: 10.1016/j.jhazmat.2019.121906] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 06/10/2023]
Abstract
Nitriles are a class of extremely toxic chemicals with extensive applications, and these compounds pose potential risks to humans and ecosystems. The activated sludge isolate Rhodococcus rhodochrous BX2 efficiently metabolizes aliphatic nitriles. However, the molecular underpinnings of the degradation mechanism of aliphatic nitriles by BX2 remain unknown, and the metabolic fate of aliphatic nitriles also has not been elucidated. Here, strain BX2 was capable of completely mineralizing three aliphatic nitriles. Bioinformatic analysis yielded a deeper insight into the genetic basis of BX2 for efficient degradation of aliphatic nitriles and adaptation to harsh environments. Transcriptional, enzyme activity and metabolite analyses confirmed that the intracellular inducible nitrile hydratase/amidase pathway is the preferred metabolic pathway. Our findings provide an in-depth understanding of the environmental fate of aliphatic nitriles and, most importantly, offer a new perspective on the potential applications of the genus Rhodococcus in bioremediation and the development of degradation enzyme resources.
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Affiliation(s)
- Xuejiao An
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Yi Cheng
- College of Science, China Agricultural University, Beijing 100083, PR China
| | - Lei Miao
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Xi Chen
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Hailian Zang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Chunyan Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
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Zhang X, Xia S, Zhao R, Wang H. Effect of temperature on opportunistic pathogen gene markers and microbial communities in long-term stored roof-harvested rainwater. ENVIRONMENTAL RESEARCH 2020; 181:108917. [PMID: 31759642 DOI: 10.1016/j.envres.2019.108917] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 11/07/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Roof-harvested rainwater (RHRW) has received increasing attention in recent years as an alternative water source for domestic use, yet its biological stability during storage is not fully understood. This study investigated the effects of temperature (4 °C, 20 °C and 30 °C) on the microbiological characteristics of RHRW over a storage period of 60 days by targeting different microbial groups including total bacteria and fecal indictor Escherichia coli, bacterial opportunistic pathogen genera and species (Legionella spp, Legionella pneumophila, Mycobacterium spp, Mycobacterium avium, Pseudomonas aeruginosa), and two amoebas (Acanthamoeba and Vermamoeba vermiformis). The rainwater chemistry demonstrated no obvious change during storage. The highest biomass was observed in RHRW stored at 30 °C, as measured by heterotrophic bacterial counts, adenosine triphosphate, and 16S rRNA gene numbers. Gene markers of E. coli, Legionella spp., P. aeruginosa, and V. vermiformis were detected in fresh RHRW and can persist during RHRW storage; whereas P. aeruginosa was the only species demonstrated significant regrowth at higher storage temperatures (P < 0.05). Acanthamoeba spp. was only detected in RHRW after 50 days of storage at three investigated temperatures, highlighting increased health risks in long-term stored RHRW. Bacterial community compositions were significantly different in RHRW stored at different temperatures, with increased variations among triplicate storage bottles noted at higher temperatures along with storage time. The results provide insights into RHRW storage practices in terms of mitigating microbial contamination risks.
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Affiliation(s)
- Xiaodong Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Renzun Zhao
- Civil, Architectural and Environmental Engineering Department, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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Santoshkumar M, Ismailsab M, Nayak AS, Mashetty SB, Karegoudar T. Purification and characterization of amidase from Paracoccus sp. SKG: Utilization of amidase-inhibited whole cells for bioconversion of acrylonitrile to acrylamide. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ruan LT, Zheng RC, Zheng YG. A novel amidase from Brevibacterium epidermidis ZJB-07021: gene cloning, refolding and application in butyrylhydroxamic acid synthesis. ACTA ACUST UNITED AC 2016; 43:1071-83. [DOI: 10.1007/s10295-016-1786-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 05/21/2016] [Indexed: 10/21/2022]
Abstract
Abstract
A novel amidase gene (bami) was cloned from Brevibacterium epidermidis ZJB-07021 by combination of degenerate PCR and high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR). The deduced amino acid sequence showed low identity (≤55 %) with other reported amidases. The bami gene was overexpressed in Escherichia coli, and the resultant inclusion bodies were refolded and purified to homogeneity with a recovery of 22.6 %. Bami exhibited a broad substrate spectrum towards aliphatic, aromatic and heterocyclic amides, and showed the highest acyl transfer activity towards butyramide with specific activity of 1331.0 ± 24.0 U mg−1. Kinetic analysis demonstrated that purified Bami exhibited high catalytic efficiency (414.9 mM−1 s−1) for acyl transfer of butyramide, with turnover number (K cat) of 3569.0 s−1. Key parameters including pH, substrate/co-substrate concentration, reaction temperature and catalyst loading were investigated and the Bami showed maximum acyl transfer activity at 50 °C, pH 7.5. Enzymatic catalysis of 200 mM butyramide with 15 μg mL−1 purified Bami was completed in 15 min with a BHA yield of 88.1 % under optimized conditions. The results demonstrated the great potential of Bami for the production of a variety of hydroxamic acids.
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Affiliation(s)
- Li-Tao Ruan
- grid.469325.f 000000041761325X Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
- grid.469325.f 000000041761325X Engineering Research Center of Bioconversion and Biopurification of Ministry of Education Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
| | - Ren-Chao Zheng
- grid.469325.f 000000041761325X Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
- grid.469325.f 000000041761325X Engineering Research Center of Bioconversion and Biopurification of Ministry of Education Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
| | - Yu-Guo Zheng
- grid.469325.f 000000041761325X Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
- grid.469325.f 000000041761325X Engineering Research Center of Bioconversion and Biopurification of Ministry of Education Zhejiang University of Technology 310014 Hangzhou People’s Republic of China
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Ramteke PW, Maurice NG, Joseph B, Wadher BJ. Nitrile-converting enzymes: an eco-friendly tool for industrial biocatalysis. Biotechnol Appl Biochem 2014; 60:459-81. [PMID: 23826937 DOI: 10.1002/bab.1139] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/21/2013] [Indexed: 11/10/2022]
Abstract
Nitriles are organic compounds bearing a − C ≡ N group; they are frequently known to occur naturally in both fauna and flora and are also synthesized chemically. They have wide applicability in the fields of medicine, industry, and environmental monitoring. However, the majority of nitrile compounds are considered to be lethal, mutagenic, and carcinogenic in nature and are known to cause potential health problems such as nausea, bronchial irritation, respiratory distress, convulsions, coma, and skeletal deformities in humans. Nitrile-converting enzymes, which are extracted from microorganisms, are commonly termed nitrilases and have drawn the attention of researchers all over the world to combat the toxicity of nitrile compounds. The present review focuses on the utility of nitrile-converting enzymes, sources, classification, structure, properties, and applications, as well as the future perspective on nitrilases.
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Affiliation(s)
- Pramod W Ramteke
- Department of Biological Sciences, Sam Higginbotom Institute of Agriculture, Technology and Sciences, Allahabad, India
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Chen S, Gao H, Chen J, Wu J. Surface modification of polyacrylonitrile fibre by nitrile hydratase from Corynebacterium nitrilophilus. Appl Biochem Biotechnol 2014; 174:2058-66. [PMID: 25163886 DOI: 10.1007/s12010-014-1186-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 08/15/2014] [Indexed: 11/24/2022]
Abstract
Previously, nitrile hydratase (NHase) from Corynebacterium nitrilophilus was obtained and showed potential in polyacrylonitrile (PAN) fibre modification. In the present study, the modification conditions of C. nitrilophilus NHase on PAN were investigated. In the optimal conditions, the wettability and dyeability (anionic and reactive dyes) of PAN treated by C. nitrilophilus NHase reached a similar level of those treated by alkali. In addition, the chemical composition and microscopically observable were changed in the PAN surface after NHase treatment. Meanwhile, it revealed that cutinase combined with NHase facilitates the PAN hydrolysis slightly because of the ester existed in PAN as co-monomer was hydrolyzed. All these results demonstrated that C. nitrilophilus NHase can modify PAN efficiently without textile structure damage, and this study provides a foundation for the further application of C. nitrilophilus NHase in PAN modification industry.
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Affiliation(s)
- Sheng Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Ave., Wuxi, Jiangsu, 214122, China
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Nitrilase superfamily aryl acylamidase from the halotolerant mangrove Streptomyces sp. 211726. Appl Microbiol Biotechnol 2014; 98:8583-90. [DOI: 10.1007/s00253-014-5762-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022]
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Purification of an amide hydrolase DamH from Delftia sp. T3-6 and its gene cloning, expression, and biochemical characterization. Appl Microbiol Biotechnol 2014; 98:7491-9. [DOI: 10.1007/s00253-014-5710-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 03/17/2014] [Indexed: 11/26/2022]
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12
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Duca D, Lorv J, Patten CL, Rose D, Glick BR. Indole-3-acetic acid in plant-microbe interactions. Antonie van Leeuwenhoek 2014; 106:85-125. [PMID: 24445491 DOI: 10.1007/s10482-013-0095-y] [Citation(s) in RCA: 325] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/07/2013] [Indexed: 01/04/2023]
Abstract
Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis.
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Affiliation(s)
- Daiana Duca
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada,
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Kamble AL, Banoth L, Meena VS, Singh A, Chisti Y, Banerjee UC. Nitrile hydratase of Rhodococcus erythropolis: characterization of the enzyme and the use of whole cells for biotransformation of nitriles. 3 Biotech 2013; 3:319-330. [PMID: 28324592 PMCID: PMC3723861 DOI: 10.1007/s13205-012-0104-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 11/28/2012] [Indexed: 11/16/2022] Open
Abstract
The intracellular cobalt-type nitrile hydratase was purified from the bacterium Rhodococcuserythropolis. The pure enzyme consisted of two subunits of 29 and 30 kDa. The molecular weight of the native enzyme was estimated to be 65 kDa. At 25 °C the enzyme had a half-life of 25 h. The Michaelis–Menten constants Km and vmax for the enzyme were 0.624 mM and 5.12 μmol/min/mg, respectively, using 3-cyanopyridine as the substrate. The enzyme-containing freely-suspended bacterial cells and the cells immobilized within alginate beads were evaluated for converting the various nitriles to amides. In a packed bed reactor, alginate beads (2 % alginate; 3 mm bead diameter) containing 200 mg/mL of cells, achieved a conversion of >90 % for benzonitrile and 4-cyanopyridine in 38 h (25 °C, pH 7.0) at a feed substrate concentration of 100 mM. The beads could be reused for up to six reaction cycles.
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Mehta PK, Bhatia SK, Bhatia RK, Bhalla TC. Purification and characterization of a novel thermo-active amidase from Geobacillus subterraneus RL-2a. Extremophiles 2013; 17:637-48. [DOI: 10.1007/s00792-013-0547-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 05/12/2013] [Indexed: 11/30/2022]
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Shen W, Chen H, Jia K, Ni J, Yan X, Li S. Cloning and characterization of a novel amidase from Paracoccus sp. M-1, showing aryl acylamidase and acyl transferase activities. Appl Microbiol Biotechnol 2011; 94:1007-18. [PMID: 22101784 DOI: 10.1007/s00253-011-3704-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 10/04/2011] [Accepted: 11/02/2011] [Indexed: 11/29/2022]
Abstract
A novel amidase gene, designated pamh, was cloned from Paracoccus sp. M-1. Site-directed mutagenesis and bioinformatic analysis showed that the PamH protein belonged to the amidase signature enzyme family. PamH was expressed in Escherichia coli, purified, and characterized. The molecular mass of PamH was determined to be 52 kDa with an isoelectric point of 5.13. PamH displayed its highest enzymatic activity at 45°C and at pH 8.0 and was stable within a pH range of 5.0-10.0. The PamH enzyme exhibited amidase activity, aryl acylamidase activity, and acyl transferase activity, allowing it to function across a very broad substrate spectrum. PamH was highly active on aromatic and short-chain aliphatic amides (benzamide and propionamide), moderately active on amino acid amides, and possessed weak urease activity. Of the anilides examined, only propanil was a good substrate for PamH. For propanil, the k (cat) and K (m) were 2.8 s(-1) and 158 μM, respectively, and the catalytic efficiency value (k (cat)/K (m)) was 0.018 μM(-1) s(-1). In addition, PamH was able to catalyze the acyl transfer reaction to hydroxylamine for both amide and anilide substrates, including acetamide, propanil, and 4-nitroacetanilide; the highest reaction rate was shown with isobutyramide. These characteristics make PamH an excellent candidate for environmental remediation and an important enzyme for the biosynthesis of novel amides.
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Affiliation(s)
- Weiliang Shen
- Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, People's Republic of China
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Discovery and molecular basis of potent noncovalent inhibitors of fatty acid amide hydrolase (FAAH). Proc Natl Acad Sci U S A 2011; 108:7379-84. [PMID: 21502526 DOI: 10.1073/pnas.1016167108] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fatty acid amide hydrolase (FAAH), an amidase-signature family member, is an integral membrane enzyme that degrades lipid amides including the endogenous cannabinoid anandamide and the sleep-inducing molecule oleamide. Both genetic knock out and pharmacological administration of FAAH inhibitors in rodent models result in analgesic, anxiolytic, and antiinflammatory phenotypes. Targeting FAAH activity, therefore, presents a promising new therapeutic strategy for the treatment of pain and other neurological-related or inflammatory disorders. Nearly all FAAH inhibitors known to date attain their binding potency through a reversible or irreversible covalent modification of the nucleophile Ser241 in the unusual Ser-Ser-Lys catalytic triad. Here, we report the discovery and mechanism of action of a series of ketobenzimidazoles as unique and potent noncovalent FAAH inhibitors. Compound 2, a representative of these ketobenzimidazoles, was designed from a series of ureas that were identified from high-throughput screening. While urea compound 1 is characterized as an irreversible covalent inhibitor, the cocrystal structure of FAAH complexed with compound 2 reveals that these ketobenzimidazoles, though containing a carbonyl moiety, do not covalently modify Ser241. These inhibitors achieve potent inhibition of FAAH activity primarily from shape complementarity to the active site and through numerous hydrophobic interactions. These noncovalent compounds exhibit excellent selectivity and good pharmacokinetic properties. The discovery of this distinctive class of inhibitors opens a new avenue for modulating FAAH activity through nonmechanism-based inhibition.
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Lavrov KV, Zalunin IA, Kotlova EK, Yanenko AS. A new acylamidase from Rhodococcus erythropolis TA37 can hydrolyze N-substituted amides. BIOCHEMISTRY (MOSCOW) 2010; 75:1006-13. [DOI: 10.1134/s0006297910080080] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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A new aryl acylamidase from Rhodococcus sp. strain Oct1 acting on ω-lactams: Its characterization and gene expression in Escherichia coli. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2009.09.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yue Y, Lian J, Tian P, Tan T. Cloning of amidase gene from Rhodococcus erythropolis and expression by distinct promoters in Bacillus subtilis. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2008.05.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Understanding structural/functional properties of amidase from Rhodococcus erythropolis by computational approaches. J Mol Model 2008; 15:481-7. [PMID: 19085025 DOI: 10.1007/s00894-008-0406-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2008] [Accepted: 08/24/2008] [Indexed: 10/21/2022]
Abstract
The 3D structure of the amidase from Rhodococcus erythropolis (EC 3.5.1.4) built by homology-based modeling is presented. Propionamide and acetamide are docked to the amidase. The reaction models were used to characterize the explicit enzymatic reaction. The calculated free energy barrier at B3LYP/6-31G* level of Model A (Ser194 + propionamide) is 19.72 kcal mol(-1) in gas (6.47 kcal mol(-1) in solution), and of Model B (Ser194 + Gly193 + propionamide) is 18.71 kcal mol(-1) in gas (4.57 kcal mol(-1) in solution). The docking results reveal that propionamide binds more strongly than acetamide due to the ethyl moiety of propionamide, which makes the carboxyl oxygen center of the substrate slightly more negative, making formation of the positively charged tetrahedral intermediate slightly easier. The quantum mechanics results demonstrate that Ser194 is essential for the acyl-intermediate, and Gly193 plays a secondary role in stabilizing acyl-intermediate formation as the NH groups of Ser194 and Gly193 form hydrogen bonds with the carbonyl oxygen of propionamide. The new structural and mechanistic insights gained from this computational study should be useful in elucidating the detailed structures and mechanisms of amidase and other homologous members of the amidase signature family.
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21
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Ewert C, Lutz-Wahl S, Fischer L. Enantioselective conversion of α-arylnitriles by Klebsiella oxytoca. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.tetasy.2008.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Jin SJ, Zheng RC, Zheng YG, Shen YC. R-enantioselective hydrolysis of 2,2-dimethylcyclopropanecarboxamide by amidase from a newly isolated strainBrevibacterium epidermidisZJB-07021. J Appl Microbiol 2008; 105:1150-7. [DOI: 10.1111/j.1365-2672.2008.03841.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Sari MA, Jaouen M, Saroja NR, Artaud I. Influence of cobalt substitution on the activity of iron-type nitrile hydratase: are cobalt type nitrile hydratases regulated by carbon monoxide? J Inorg Biochem 2006; 101:614-22. [PMID: 17267045 DOI: 10.1016/j.jinorgbio.2006.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/07/2006] [Accepted: 12/08/2006] [Indexed: 11/15/2022]
Abstract
Comamonas testosteroni Ni1 nitrile hydratase is a Fe-type nitrile hydratase whose native and recombinant forms are identical. Here, the iron of Ni1 nitrile hydratase was replaced by cobalt using a chaperone based Escherichia coli expression system. Cobalt (CoNi1) and iron (FeNi1) enzymes share identical Vmax (30 nmol min(-1) mg(-1)) and Km (200 microM) toward their substrate and identical Ki values for the known competitive inhibitors of FeNi1. However, nitrophenols used as inhibitors do display a different inhibition pattern on both enzymes. Furthermore, CoNi1 and FeNi1 are also different in their sensitivity to nitric oxide and carbon monoxide, CO being selective of the cobalt enzyme. These differences are rationalized in relation to the nature of the catalytic metal center in the enzyme.
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Affiliation(s)
- Marie-Agnès Sari
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université René Descartes, UMR 8601 CNRS, 45 Rue des Saint-Pères, 75270 Paris Cedex 06, France.
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Pollmann S, Neu D, Lehmann T, Berkowitz O, Schäfer T, Weiler EW. Subcellular localization and tissue specific expression of amidase 1 from Arabidopsis thaliana. PLANTA 2006; 224:1241-53. [PMID: 16738862 DOI: 10.1007/s00425-006-0304-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Accepted: 04/25/2006] [Indexed: 05/09/2023]
Abstract
Amidase 1 (AMI1) from Arabidopsis thaliana converts indole-3-acetamide (IAM), into indole-3-acetic acid (IAA). AMI1 is part of a small isogene family comprising seven members in A. thaliana encoding proteins which share a conserved glycine- and serine-rich amidase-signature. One member of this family has been characterized as an N-acylethanolamine-cleaving fatty acid amidohydrolase (FAAH) and two other members are part of the preprotein translocon of the outer envelope of chloroplasts (Toc complex) or mitochondria (Tom complex) and presumably lack enzymatic activity. Among the hitherto characterized proteins of this family, AMI1 is the only member with indole-3-acetamide hydrolase activity, and IAM is the preferred substrate while N-acylethanolamines and oleamide are not hydrolyzed significantly, thus suggesting a role of AMI1 in auxin biosynthesis. Whereas the enzymatic function of AMI1 has been determined in vitro, the subcellular localization of the enzyme remained unclear. By using different GFP-fusion constructs and an A. thaliana transient expression system, we show a cytoplasmic localization of AMI1. In addition, RT-PCR and anti-amidase antisera were used to examine tissue specific expression of AMI1 at the transcriptional and translational level, respectively. AMI1-expression is strongest in places of highest IAA content in the plant. Thus, it is concluded that AMI1 may be involved in de novo IAA synthesis in A. thaliana.
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Affiliation(s)
- Stephan Pollmann
- Department of Plant Physiology, Ruhr-University Bochum, Universitaetsstrasse 150, ND 2/27, 44801 Bochum, Germany.
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25
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Ryabchenko LE, Podchernyaev DA, Kotlova EK, Yanenko AS. Cloning the amidase gene from Rhodococcus rhodochrous M8 and its expression in Escherichia coli. RUSS J GENET+ 2006. [DOI: 10.1134/s1022795406080060] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Cameron RA, Sayed M, Cowan DA. Molecular analysis of the nitrile catabolism operon of the thermophile Bacillus pallidus RAPc8. Biochim Biophys Acta Gen Subj 2005; 1725:35-46. [PMID: 15955632 DOI: 10.1016/j.bbagen.2005.03.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 03/24/2005] [Accepted: 03/28/2005] [Indexed: 11/19/2022]
Abstract
The gene cluster containing the nitrile hydratase (NHase) and amidase genes of a moderate thermophile, B. pallidus RAPc8 has been cloned and sequenced. The (5.9 kb) section of cloned DNA contained eight complete open reading frames, encoding (in order), amidase (belonging to the nitrilase related aliphatic amidase family), nitrile hydratase beta and alpha subunits (of the cobalt containing class), a 122-amino acid accessory protein, designated P14K, a homologue of the 2Fe-2S class of ferredoxins and three putative proteins with distinct homology to the cobalt uptake proteins cbiM, cbiN and cbiQ of the S. typhimurium LT2 cobalamin biosynthesis pathway. The amidase and nitrile hydratase genes were subcloned and inducibly expressed in Escherichia coli, to levels of approximately 37 U/mg and 49 U/mg, respectively, without the co-expression of additional flanking genes. However, co-expression of P14K with the NHase structural genes significantly enhanced the specific activity of the recombinant NHase. This is the first description of an accessory protein involved in thermostable NHase expression. Modelling of the P14K protein structure has suggested that this protein functions as a subunit-specific chaperone, aiding in the folding of the NHase alpha subunit prior to alpha-beta subunit association and the formation of alpha(2)beta(2) NHase holoenzyme.
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Affiliation(s)
- Rory A Cameron
- Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Bellville 7535, Cape Town, South Africa
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27
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Hongpattarakere T, Komeda H, Asano Y. Purification, characterization, gene cloning and nucleotide sequencing of D-stereospecific amino acid amidase from soil bacterium: Delftia acidovorans. J Ind Microbiol Biotechnol 2005; 32:567-76. [PMID: 15959727 DOI: 10.1007/s10295-005-0246-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
The D-amino acid amidase-producing bacterium was isolated from soil samples using an enrichment culture technique in medium broth containing D-phenylalanine amide as a sole source of nitrogen. The strain exhibiting the strongest activity was identified as Delftia acidovorans strain 16. This strain produced intracellular D-amino acid amidase constitutively. The enzyme was purified about 380-fold to homogeneity and its molecular mass was estimated to be about 50 kDa, on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme was active preferentially toward D-amino acid amides rather than their L-counterparts. It exhibited strong amino acid amidase activity toward aromatic amino acid amides including D-phenylalanine amide, D-tryptophan amide and D-tyrosine amide, yet it was not specifically active toward low-molecular-weight D-amino acid amides such as D-alanine amide, L-alanine amide and L-serine amide. Moreover, it was not specifically active toward oligopeptides. The enzyme showed maximum activity at 40 degrees C and pH 8.5 and appeared to be very stable, with 92.5% remaining activity after the reaction was performed at 45 degrees C for 30 min. However, it was mostly inactivated in the presence of phenylmethanesulfonyl fluoride or Cd2+, Ag+, Zn2+, Hg2+ and As3+ . The NH2 terminal and internal amino acid sequences of the enzyme were determined; and the gene was cloned and sequenced. The enzyme gene damA encodes a 466-amino-acid protein (molecular mass 49,860.46 Da); and the deduced amino acid sequence exhibits homology to the D-amino acid amidase from Variovorax paradoxus (67.9% identity), the amidotransferase A subunit from Burkholderia fungorum (50% identity) and other enantioselective amidases.
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28
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29
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Inoue A, Komeda H, Asano Y. Asymmetric Synthesis ofL-α-Methylcysteine with the Amidase fromXanthobacter flavus NR303. Adv Synth Catal 2005. [DOI: 10.1002/adsc.200505028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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O'Mahony R, Doran J, Coffey L, Cahill OJ, Black GW, O'Reilly C. Characterisation of the nitrile hydratase gene clusters of Rhodococcus erythropolis strains AJ270 and AJ300 and Microbacterium sp. AJ115 indicates horizontal gene transfer and reveals an insertion of IS1166. Antonie van Leeuwenhoek 2005; 87:221-32. [PMID: 15803388 DOI: 10.1007/s10482-004-3721-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Accepted: 09/23/2004] [Indexed: 10/25/2022]
Abstract
The nitrile metabolising strains AJ270, AJ300 and AJ115 were isolated from the same location. The strains have very similar nitrile metabolising profiles. Sequencing of the 16S rRNA gene indicates that strains AJ270 and AJ300 are novel strains of Rhodococcus erythropolis while strain AJ115 is a novel Microbacterium strain very closely related to Microbacterium oxydans and Microbacterium liquefaciens. Analysis of the structure of the nitrile hydratase/amidase gene clusters in the three strains indicates that this region is identical in these strains and that this structure is different to other nitrile hydratase/amidase gene clusters. The major difference seen is the insertion of a complete copy of the insertion sequence IS1166 in the nhr2 gene. This copy of IS1166 generates a 10 bp direct duplication at the point of insertion and has one ORF encoding a protein of 434 amino acids, with 98% homology to the transposase of IS666 from Mycobacterium avium. A gene oxd, encoding aldoxime dehydratase is found upstream of the nitrile hydratase gene cluster and an open reading frame encoding a protein with homology to GlnQ type ABC transporters is found downstream of the nitrile hydratase/amidase genes. The identity of the nitrile hydratase/amidase gene clusters in the three strains suggests horizontal gene transfer of this region. Analysis of the strains for both linear and circular plasmids indicates that both are present in the strains but hybridisation studies indicate that the nitrile hydratase/amidase gene cluster is chromosomally located. The nitrile hydratase/amidase enzymes of strain AJ270 are inducible with acetonitrile or acetamide. Interestingly although a number of Fe-type nitrile hydratases have been shown to be photosensitive, the enzyme from strain AJ270 is not.
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Affiliation(s)
- Rebecca O'Mahony
- Department of Chemical and Life Sciences, Waterford Institute of Technology, Cork Road, Waterford, Ireland
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31
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Nitrile Degradation by Rhodococcus: Useful Microbial Metabolism for Industrial Productions. ACTA ACUST UNITED AC 2005. [DOI: 10.3209/saj.19.18] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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32
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33
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Reisinger C, Osprian I, Glieder A, Schoemaker HE, Griengl H, Schwab H. Enzymatic hydrolysis of cyanohydrins with recombinant nitrile hydratase and amidase from hodococcus erythropolis. Biotechnol Lett 2004; 26:1675-80. [PMID: 15604819 DOI: 10.1007/s10529-004-3521-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nitrile hydratase and amidase from Rhodococcus erythropolis CIMB11540 were both cloned and expressed in Escherichia coli. Crude cell free extracts were used for the hydrolysis of different aromatic cyanohydrins. Nitrile hydratase expression was increased up to 5-fold by redesign of the expression cassette. The recombinant enzymes were successfully used for the conversion of several cyanohydrins to the corresponding alpha-hydroxy amides and acids while retaining enantiopurity.
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Affiliation(s)
- Ch Reisinger
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, Graz, 8010, Austria
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34
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Gopalakrishna KN, Stewart BH, Kneen MM, Andricopulo AD, Kenyon GL, McLeish MJ. Mandelamide hydrolase from Pseudomonas putida: characterization of a new member of the amidase signature family. Biochemistry 2004; 43:7725-35. [PMID: 15196015 DOI: 10.1021/bi049907q] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A recently discovered enzyme in the mandelate pathway of Pseudomonas putida, mandelamide hydrolase (MAH), catalyzes the hydrolysis of mandelamide to mandelic acid and ammonia. Sequence analysis suggests that MAH is a member of the amidase signature family, which is widespread in nature and contains a novel Ser-cis-Ser-Lys catalytic triad. Here we report the expression in Escherichia coli, purification, and characterization of both wild-type and His(6)-tagged MAH. The recombinant enzyme was stable, exhibited a pH optimum of 7.8, and was able to hydrolyze both enantiomers of mandelamide with little enantiospecificity. The His-tagged variant showed no significant change in kinetic constants. Phenylacetamide was found to be the best substrate, with changes in chain length or replacement of the phenyl group producing greatly decreased values of k(cat)/K(m). As with another member of this family, fatty acid amide hydrolase, MAH has the uncommon ability to hydrolyze esters and amides at similar rates. MAH is even more unusual in that it will only hydrolyze esters and amides with little steric bulk. Ethyl and larger esters and N-ethyl and larger amides are not substrates, suggesting that the MAH active site is very sterically hindered. Mutation of each residue in the putative catalytic triad to alanine resulted in total loss of activity for S204A and K100A, while S180A exhibited a 1500-fold decrease in k(cat) and significant increases in K(m) values. Overall, the MAH data are similar to those of fatty acid amide hydrolase and support the suggestion that there are two distinct subgroups within the amidase signature family.
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Affiliation(s)
- Kota N Gopalakrishna
- College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109-1065, USA
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35
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Komeda H, Harada H, Washika S, Sakamoto T, Ueda M, Asano Y. A novel R-stereoselective amidase from Pseudomonas sp. MCI3434 acting on piperazine-2-tert-butylcarboxamide. ACTA ACUST UNITED AC 2004; 271:1580-90. [PMID: 15066183 DOI: 10.1111/j.1432-1033.2004.04069.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas sp. MCI3434 and characterized. The enzyme acted R-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (R)-piperazine-2-carboxylic acid, and was tentatively named R-amidase. The N-terminal amino acid sequence of the enzyme showed high sequence identity with that deduced from a gene named PA3598 encoding a hypothetical hydrolase in Pseudomonas aeruginosa PAO1. The gene encoding R-amidase was cloned from the genomic DNA of Pseudomonas sp. MCI3434 and sequenced. Analysis of 1332 bp of the genomic DNA revealed the presence of one open reading frame (ramA) which encodes the R-amidase. This enzyme, RamA, is composed of 274 amino acid residues (molecular mass, 30 128 Da), and the deduced amino acid sequence exhibits homology to a carbon-nitrogen hydrolase protein (PP3846) from Pseudomonas putida strain KT2440 (72.6% identity) and PA3598 protein from P. aeruginosa strain PAO1 (65.6% identity) and may be classified into a new subfamily in the carbon-nitrogen hydrolase family consisting of aliphatic amidase, beta-ureidopropionase, carbamylase, nitrilase, and so on. The amount of R-amidase in the supernatant of the sonicated cell-free extract of an Escherichia coli transformant overexpressing the ramA gene was about 30 000 times higher than that of Pseudomonas sp. MCI3434. The intact cells of the E. coli transformant could be used for the R-stereoselective hydrolysis of racemic piperazine-2-tert-butylcarboxamide. The recombinant enzyme was purified to electrophoretic homogeneity from cell-free extract of the E. coli transformant overexpressing the ramA gene. On gel-filtration chromatography, the enzyme appeared to be a monomer. It had maximal activity at 45 degrees C and pH 8.0, and was completely inactivated in the presence of p-chloromercuribenzoate, N-ethylmaleimide, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, or Pb2+. RamA had hydrolyzing activity toward the carboxamide compounds, in which amino or imino group is connected to beta- or gamma-carbon, such as beta-alaninamide, (R)-piperazine-2-carboxamide (R)-piperidine-3-carboxamide, D-glutaminamide and (R)-piperazine-2-tert-butylcarboxamide. The enzyme, however, did not act on the other amide substrates for the aliphatic amidase despite its sequence similarity to RamA.
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Affiliation(s)
- Hidenobu Komeda
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Kosugi, Toyama 939-0398, Japan
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36
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Komeda H, Harada H, Washika S, Sakamoto T, Ueda M, Asano Y. S -Stereoselective piperazine-2-tert-butylcarboxamide hydrolase from Pseudomonas azotoformans IAM 1603 is a novel l-amino acid amidase. ACTA ACUST UNITED AC 2004; 271:1465-75. [PMID: 15066172 DOI: 10.1111/j.1432-1033.2004.04056.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas azotoformans IAM 1603 and characterized. The enzyme acted S-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (S)-piperazine-2-carboxylic acid. N-terminal and internal amino acid sequences of the enzyme were determined. The gene encoding the S-stereoselective piperazine-2-tert-butylcarboxamide amidase was cloned from the chromosomal DNA of the strain and sequenced. Analysis of 2.1 kb of genomic DNA revealed the presence of two ORFs, one of which (laaA) encodes the amidase. This enzyme, LaaA is composed of 310 amino acid residues (molecular mass 34 514 Da), and the deduced amino acid sequence exhibits significant similarity to hypothetical and functionally characterized proline iminopeptidases from several bacteria. The laaA gene modified in the nucleotide sequence upstream from its start codon was overexpressed in Escherichia coli. The activity of the recombinant LaaA enzyme in cell-free extracts of E. coli was 13.1 units.mg(-1) with l-prolinamide as substrate. This enzyme was purified to electrophoretic homogeneity by ammonium sulfate fractionation and two column chromatography steps. On gel-filtration chromatography, the enzyme appeared to be a monomer with a molecular mass of 32 kDa. It had maximal activity at 45 degrees C and pH 9.0, and was completely inactivated in the presence of phenylhydrazine, Zn2+, Ag+, Cd2+ or Hg2+. LaaA had hydrolyzing activity toward L-amino acid amides such as L-prolinamide, L-proline-p-nitroanilide, L-alaninamide and L-methioninamide, but did not act on the peptide substrates for the proline iminopeptidases despite their sequence similarity to LaaA. The enzyme also acted S-stereoselectively on (R,S)-piperidine-2-carboxamide, (R,S)-piperazine-2-carboxamide and (R,S)-piperazine-2-tert-butylcarboxamide. Based on its specificity towards L-amino acid amides, the enzyme was named L-amino acid amidase. E. coli transformants overexpressing the laaA gene could be used for the S-stereoselective hydrolysis of (R,S)-piperazine-2-tert-butylcarboxamide.
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Affiliation(s)
- Hidenobu Komeda
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Kosugi, Toyama 939-0398, Japan
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37
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Brandão PFB, Clapp JP, Bull AT. Diversity of nitrile hydratase and amidase enzyme genes in Rhodococcus erythropolis recovered from geographically distinct habitats. Appl Environ Microbiol 2003; 69:5754-66. [PMID: 14532022 PMCID: PMC201182 DOI: 10.1128/aem.69.10.5754-5766.2003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2003] [Accepted: 07/09/2003] [Indexed: 11/20/2022] Open
Abstract
A molecular screening approach was developed in order to amplify the genomic region that codes for the alpha- and beta-subunits of the nitrile hydratase (NHase) enzyme in rhodococci. Specific PCR primers were designed for the NHase genes from a collection of nitrile-degrading actinomycetes, but amplification was successful only with strains identified as Rhodococcus erythropolis. A hydratase PCR product was also obtained from R. erythropolis DSM 43066(T), which did not grow on nitriles. Southern hybridization of other members of the nitrile-degrading bacterial collection resulted in no positive signals other than those for the R. erythropolis strains used as positive controls. PCR-restriction fragment length polymorphism-single-strand conformational polymorphism (PRS) analysis of the hydratases in the R. erythropolis strains revealed unique patterns that mostly correlated with distinct geographical sites of origin. Representative NHases were sequenced, and they exhibited more than 92.4% similarity to previously described NHases. The phylogenetic analysis and deduced amino acid sequences suggested that the novel R. erythropolis enzymes belonged to the iron-type NHase family. Some different residues in the translated sequences were located near the residues involved in the stabilization of the NHase active site, suggesting that the substitutions could be responsible for the different enzyme activities and substrate specificities observed previously in this group of actinomycetes. A similar molecular screening analysis of the amidase gene was performed, and a correlation between the PRS patterns and the geographical origins identical to the correlation found for the NHase gene was obtained, suggesting that there was coevolution of the two enzymes in R. erythropolis. Our findings indicate that the NHase and amidase genes present in geographically distinct R. erythropolis strains are not globally mixed.
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Affiliation(s)
- Pedro F B Brandão
- Research School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
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38
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McKinney MK, Cravatt BF. Evidence for distinct roles in catalysis for residues of the serine-serine-lysine catalytic triad of fatty acid amide hydrolase. J Biol Chem 2003; 278:37393-9. [PMID: 12734197 DOI: 10.1074/jbc.m303922200] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fatty acid amide hydrolase (FAAH) is a mammalian amidase signature enzyme that inactivates neuromodulatory fatty acid amides, including the endogenous cannabinoid anandamide and the sleep-inducing substance oleamide. The recent determination of the three-dimensional structures of FAAH and two distantly related bacterial amidase signature enzymes indicates that these enzymes employ an unusual serine-serine-lysine triad for catalysis (Ser-241/Ser-217/Lys-142 in FAAH). Mutagenesis of each of the triad residues in FAAH has been shown to severely reduce amidase activity; however, how these residues contribute, both individually and in cooperation, to catalysis remains unclear. Here, through a combination of site-directed mutagenesis, enzyme kinetics, and chemical labeling experiments, we provide evidence that each FAAH triad residue plays a distinct role in catalysis. In particular, the mutation of Lys-142 to alanine indicates that this residue functions as both a base involved in the activation of the Ser-241 nucleophile and an acid that participates in the protonation of the substrate leaving group. This latter property appears to support the unusual ability of FAAH to hydrolyze amides and esters at equivalent rates. Interestingly, although structural evidence indicates that the impact of Lys-142 on catalysis probably occurs through the bridging Ser-217, the mutation of this latter residue to alanine impaired catalytic activity but left the amide/ester hydrolysis ratios of FAAH intact. Collectively, these findings suggest that FAAH possesses a specialized active site structure dedicated to a mechanism for competitive amide and ester hydrolysis where nucleophile attack and leaving group protonation occur in a coordinated manner dependent on Lys-142.
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Affiliation(s)
- Michele K McKinney
- Department of Cell Biology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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39
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Tsujimura M, Odaka M, Nakayama H, Dohmae N, Koshino H, Asami T, Hoshino M, Takio K, Yoshida S, Maeda M, Endo I. A novel inhibitor for Fe-type nitrile hydratase: 2-cyano-2-propyl hydroperoxide. J Am Chem Soc 2003; 125:11532-8. [PMID: 13129355 DOI: 10.1021/ja035018z] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitrile hydratase (NHase) is a non-heme iron or non-corrin cobalt enzyme having two post-translationally modified ligand residues, cysteine-sulfinic acid (alphaCys112-SO(2)H) and -sulfenic acid (alphaCys114-SOH). We studied the interaction between Fe-type NHase and isobutyronitrile (iso-BN) which had been reported as a competitive inhibitor with a K(i) value of 5 microM. From detailed kinetic studies of the inhibitory effect of iso-BN on Fe-type NHase, we found that authentic iso-BN was hydrated normally and that the impurity present in commercially available iso-BN inhibited NHase activity strongly. The inhibitory compound induced significant changes in the UV-vis absorption spectrum of NHase, suggesting its interaction with the iron center. This compound was purified by using reversed-phase HPLC and identified as 2-cyano-2-propyl hydroperoxide (Cpx) by (1)H and PFG-HMBC NMR spectroscopy. Upon addition of a stoichiometric amount of Cpx, NHase was irreversibly inactivated, probably by the oxidation of alphaCys114-SOH to Cys-SO(2)H. This result suggests that the -SOH structure of alphaCys114 is essential for the catalytic activity. The oxygen atom in Cys-SO(2)H is confirmed to come from the solvent H(2)O. The oxidized NHase was found to induce the UV-vis absorption spectral changes by addition of Cpx, suggesting that Cpx strongly interacted with iron(III) in the oxidized NHase to form a stable complex. Thus, Cpx functions as a novel irreversible inhibitor for NHase.
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Affiliation(s)
- Masanari Tsujimura
- Biomolecular Characterization Division, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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40
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Shrestha R, Dixon RA, Chapman KD. Molecular identification of a functional homologue of the mammalian fatty acid amide hydrolase in Arabidopsis thaliana. J Biol Chem 2003; 278:34990-7. [PMID: 12824167 DOI: 10.1074/jbc.m305613200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-Acylethanolamines (NAEs) are endogenous constituents of plant and animal tissues, and in vertebrates their hydrolysis terminates their participation as lipid mediators in the endocannabinoid signaling system. The membrane-bound enzyme responsible for NAE hydrolysis in mammals has been identified at the molecular level (designated fatty acid amide hydrolase, FAAH), and although an analogous enzyme activity was identified in microsomes of cotton seedlings, no molecular information is available for this enzyme in plants. Here we report the identification, the heterologous expression (in Escherichia coli), and the biochemical characterization of an Arabidopsis thaliana FAAH homologue. Candidate Arabidopsis DNA sequences containing a characteristic amidase signature sequence (PS00571) were identified in plant genome data bases, and a cDNA was isolated by reverse transcriptase-PCR using Arabidopsis genome sequences to develop appropriate oligonucleotide primers. The cDNA was sequenced and predicted to encode a protein of 607 amino acids with 37% identity to rat FAAH within the amidase signature domain (18% over the entire length). Residues determined to be important for FAAH catalysis were conserved between the Arabidopsis and rat protein sequences. In addition, a single transmembrane domain near the N terminus was predicted in the Arabidopsis protein sequence, similar to that of the rat FAAH protein. The putative plant FAAH cDNA was expressed as an epitope/His-tagged fusion protein in E. coli and solubilized from cell lysates in the nonionic detergent, dodecyl maltoside. Affinity-purified recombinant protein was indeed active in hydrolyzing a variety of naturally occurring N-acylethanolamine types. Kinetic parameters and inhibition data for the recombinant Arabidopsis protein were consistent with these properties of the enzyme activity characterized previously in plant and animal systems. Collectively these data now provide support at the molecular level for a conserved mechanism between plants and animals for the metabolism of NAEs.
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Affiliation(s)
- Rhidaya Shrestha
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, Texas 76203, USA
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41
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Stevens JM, Belghazi M, Jaouen M, Bonnet D, Schmitter JM, Mansuy D, Sari MA, Artaud I. Post-translational modification of Rhodococcus R312 and Comamonas NI1 nitrile hydratases. JOURNAL OF MASS SPECTROMETRY : JMS 2003; 38:955-961. [PMID: 14505323 DOI: 10.1002/jms.509] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nitrile hydratases (NHases) are industrially significant iron- and cobalt-containing enzymes used in the large-scale synthesis of acrylamide. Previous reports have shown that the active site peptides of NHases are post-translationally modified by oxidation of cysteine residues, and that these modifications are essential for catalysis. We report mass spectrometric evidence of the oxidation states of the active site cysteines in the iron coordination spheres of two iron-containing nitrile hydratases, namely R312 NHase from Rhodococcus rhodochrous strain R312 and NI1 NHase from Comamonas testosteroni. At least one of these cysteines is oxidised to a sulfinic acid (SO(2)H) and there is also evidence suggesting an additional oxidation to a sulfenic acid (SOH). This is the first evidence for the presence of these oxidation states for full-length NHases and for Fe-NHases from different microorganisms. The presence of these covalent modifications was confirmed by performing mass spectrometry on the active site peptide of R312 NHase, under native, reduced and carboxymethylated conditions. We also show the nitrosylation of the iron by mass spectrometry, as well as the release of NO by photoirradiation.
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Affiliation(s)
- Julie M Stevens
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (UMR 8601 CNRS), Université René Descartes Paris V, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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42
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Yamada H, Shimizu S, Kobayashi M. Hydratases involved in nitrile conversion: screening, characterization and application. CHEM REC 2003; 1:152-61. [PMID: 11893064 DOI: 10.1002/tcr.5] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The discovery of new enzymes with greater activity and specificity opens new, simple routes for synthetic processes, and consequently, new methods to solve environmental problems. A number of nitrile-related enzymes have been screened over the past few years for use in developing synthetic applications. Microbial nitrile hydratase (NHase) has great potential as a catalyst in organic chemical processing because the enzyme can convert nitriles to the corresponding higher value amides under mild conditions, and has now been applied to the industrial productions of acrylamide and nicotinamide. Particularly, the former production is the first successful example of a bioconversion process for the manufacture of a commodity chemical. The characterization of the enzyme at the molecular level has provided new insights into how the molecular structure determines the enzyme function, and how the regulatory system controls the expression of the enzyme genes to improve the enzyme and the NHase-dependent process.
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Affiliation(s)
- H Yamada
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan
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43
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Stevens JM, Rao Saroja N, Jaouen M, Belghazi M, Schmitter JM, Mansuy D, Artaud I, Sari MA. Chaperone-assisted expression, purification, and characterization of recombinant nitrile hydratase NI1 from Comamonas testosteroni. Protein Expr Purif 2003; 29:70-6. [PMID: 12729727 DOI: 10.1016/s1046-5928(03)00008-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Nitrile hydratases (NHases) are industrially important iron- and cobalt-containing enzymes that are used in the large-scale synthesis of acrylamide. Heterologous expression of NHases has been complicated by the fact that other proteins (activators or metallochaperones) appear to be required to produce NHases in their catalytically active form. We report a novel heterologous system for the expression of catalytically active iron-containing NI1 NHase in Escherichia coli, involving coexpression with the E. coli GroES and GroEL chaperones. The purified recombinant enzyme was found to be highly similar to the enzyme purified from Comamonas testosteroni according to its spectroscopic features, catalytic properties with various substrates, and post-translational modifications. In addition, we report a rapid and convenient spectrophotometric method to monitor the activity of NI1 NHase during purification.
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Affiliation(s)
- Julie M Stevens
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (UMR 8601 CNRS), Université Paris V, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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44
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McLeish MJ, Kneen MM, Gopalakrishna KN, Koo CW, Babbitt PC, Gerlt JA, Kenyon GL. Identification and characterization of a mandelamide hydrolase and an NAD(P)+-dependent benzaldehyde dehydrogenase from Pseudomonas putida ATCC 12633. J Bacteriol 2003; 185:2451-6. [PMID: 12670968 PMCID: PMC152609 DOI: 10.1128/jb.185.8.2451-2456.2003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The enzymes of the mandelate metabolic pathway permit Pseudomonas putida ATCC 12633 to utilize either or both enantiomers of mandelate as the sole carbon source. The genes encoding the mandelate pathway were found to lie on a single 10.5-kb restriction fragment. Part of that fragment was shown to contain the genes coding for mandelate racemase, mandelate dehydrogenase, and benzoylformate decarboxylase arranged in an operon. Here we report the sequencing of the remainder of the restriction fragment, which revealed three further open reading frames, denoted mdlX, mdlY, and mdlD. All were transcribed in the opposite direction from the genes of the mdlABC operon. Sequence alignments suggested that the open reading frames encoded a regulatory protein (mdlX), a member of the amidase signature family (mdlY), and an NAD(P)(+)-dependent dehydrogenase (mdlD). The mdlY and mdlD genes were isolated and expressed in Escherichia coli, and the purified gene products were characterized as a mandelamide hydrolase and an NAD(P)(+)-dependent benzaldehyde dehydrogenase, respectively.
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Affiliation(s)
- Michael J McLeish
- College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, USA.
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45
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Baek DH, Song JJ, Lee SG, Kwon SJ, Asano Y, Sung MH. New thermostable d-methionine amidase from Brevibacillus borstelensis BCS-1 and its application for d-phenylalanine production. Enzyme Microb Technol 2003. [DOI: 10.1016/s0141-0229(02)00268-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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46
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Trott S, Bürger S, Calaminus C, Stolz A. Cloning and heterologous expression of an enantioselective amidase from Rhodococcus erythropolis strain MP50. Appl Environ Microbiol 2002; 68:3279-86. [PMID: 12089004 PMCID: PMC126760 DOI: 10.1128/aem.68.7.3279-3286.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gene for an enantioselective amidase was cloned from Rhodococcus erythropolis MP50, which utilizes various aromatic nitriles via a nitrile hydratase/amidase system as nitrogen sources. The gene encoded a protein of 525 amino acids which corresponded to a protein with a molecular mass of 55.5 kDa. The deduced complete amino acid sequence showed homology to other enantioselective amidases from different bacterial genera. The nucleotide sequence approximately 2.5 kb upstream and downstream of the amidase gene was determined, but no indications for a structural coupling of the amidase gene with the genes for a nitrile hydratase were found. The amidase gene was carried by an approximately 40-kb circular plasmid in R. erythropolis MP50. The amidase was heterologously expressed in Escherichia coli and shown to hydrolyze 2-phenylpropionamide, alpha-chlorophenylacetamide, and alpha-methoxyphenylacetamide with high enantioselectivity; mandeloamide and 2-methyl-3-phenylpropionamide were also converted, but only with reduced enantioselectivity. The recombinant E. coli strain which synthesized the amidase gene was shown to grow with organic amides as nitrogen sources. A comparison of the amidase activities observed with whole cells or cell extracts of the recombinant E. coli strain suggested that the transport of the amides into the cells becomes the rate-limiting step for amide hydrolysis in recombinant E. coli strains.
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Affiliation(s)
- Sandra Trott
- Institut für Mikrobiologie, Universität Stuttgart, 70569 Stuttgart, Germany
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47
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Harpel MR, Horiuchi KY, Luo Y, Shen L, Jiang W, Nelson DJ, Rogers KC, Decicco CP, Copeland RA. Mutagenesis and mechanism-based inhibition of Streptococcus pyogenes Glu-tRNAGln amidotransferase implicate a serine-based glutaminase site. Biochemistry 2002; 41:6398-407. [PMID: 12009902 DOI: 10.1021/bi012126u] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The absence of Gln-tRNA synthetase in certain bacteria necessitates an alternate pathway for the production of Gln-tRNA(Gln): misacylated Glu-tRNA(Gln) is transamidated by a Gln-dependent amidotransferase (Glu-AdT) via catalysis of Gln hydrolysis, ATP hydrolysis, activation of Glu-tRNA(Gln), and aminolysis of activated tRNA by Gln-derived NH(3). As observed for other Gln-coupled amidotransferases, substrate binding, Gln hydrolysis, and transamidation by Glu-AdT are tightly coordinated [Horiuchi, K. Y., Harpel, M. R., Shen, L., Luo, Y., Rogers, K. C., and Copeland, R. A. (2001) Biochemistry 40, 6450-6457]. However, Glu-AdT does not employ an active-site Cys nucleophile for Gln hydrolysis, as is common in all other glutaminases: some Glu-AdT lack Cys, but all contain a conserved Ser (Ser176 in the A subunit of Streptococcus pyogenes Glu-AdT) within a sequence signature motif of Ser-based amidases. Our current results with S. pyogenes Glu-AdT support this characterization of Glu-AdT as a Ser-based glutaminase. Slow-onset (approximately 50 M(-1) s(-1)), tight-binding (t(1/2) > 2.5 h for complex dissociation), Gln-competitive inhibition of the Glu-tRNA(Gln)/ATP-independent glutaminase activity of Glu-AdT by gamma-Glu boronic acid is consistent with engagement of a Ser nucleophile in the glutaminase active site. Conversion to rapidly reversible, yet still potent (K(i) = 73 nM) and Gln-competitive, inhibition under full transamidation conditions mirrors the coupling between Gln hydrolysis and aminolysis reactions during productive transamidation. Site-directed replacement of Ser176 by Ala abolishes glutaminase and Gln-dependent transamidase activities of Glu-AdT (>300-fold), but retains a wild-type level of NH(3)-dependent transamidation activity. These results demonstrate the essentiality of Ser176 for Gln hydrolysis, provide additional support for coordinated coupling of Gln hydrolysis and transamidase transition states during catalysis, and validate glutaminase-directed inhibition of Glu-AdT as a route for antimicrobial chemotherapy.
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Affiliation(s)
- Mark R Harpel
- Chemical Enzymology Department, Bristol-Myers Squibb Company, Experimental Station, Route 141 and Henry Clay Road, Wilmington, Delaware 19880, USA.
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48
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Fraser JA, Davis MA, Hynes MJ. The genes gmdA, encoding an amidase, and bzuA, encoding a cytochrome P450, are required for benzamide utilization in Aspergillus nidulans. Fungal Genet Biol 2002; 35:135-46. [PMID: 11848676 DOI: 10.1006/fgbi.2001.1307] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two unlinked loci, gmdA and bzuA, have previously been identified as being required for the utilization of benzamide as the sole nitrogen source by Aspergillus nidulans. We have cloned each of these genes via direct complementation. The gmdA gene encodes a predicted product belonging to the amidase signature sequence family that displays similarity to AmdS from A. nidulans. However, identity is significantly higher to the amdS gene from Aspergillus niger. The bzuA gene encodes a protein belonging to the cytochrome P450 superfamily and is orthologous to the benzoate para-hydroxylase-encoding gene bphA of A. niger. The bzuA1 mutation prevents the use of benzoate as a carbon source and intracellular accumulation of benzoate results in growth inhibition on benzamide. Northern blot analysis has shown that gmdA expression is subject solely to AreA-dependent nitrogen metabolite repression while bzuA is strongly benzoate inducible and subject to CreA-mediated carbon catabolite repression and a probable inactivation of benzoate induction by glucose. Fluorescence microscopy of a fusion of the N-terminal end of BzuA to green fluorescent protein revealed that this protein localizes to the endoplasmic reticulum.
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Affiliation(s)
- James A Fraser
- Department of Genetics, University of Melbourne, Parkville, Victoria, 3010, Australia
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49
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Fournand D, Arnaud A. Aliphatic and enantioselective amidases: from hydrolysis to acyl transfer activity. J Appl Microbiol 2001; 91:381-93. [PMID: 11556902 DOI: 10.1046/j.1365-2672.2001.01378.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- D Fournand
- GER de Chimie Biologique, Institut National Agronomique Paris-Grignon, Thiverval-Grignon, France
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50
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Horiuchi KY, Harpel MR, Shen L, Luo Y, Rogers KC, Copeland RA. Mechanistic studies of reaction coupling in Glu-tRNAGln amidotransferase. Biochemistry 2001; 40:6450-7. [PMID: 11371208 DOI: 10.1021/bi002599l] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Organisms lacking Gln-tRNA synthetase produce Gln-tRNA(Gln) from misacylated Glu-tRNA(Gln) through the transamidation activity of Glu-tRNA(Gln) amidotransferase (Glu-AdT). Glu-AdT hydrolyzes Gln to Glu and NH(3), using the latter product to transamidate Glu-tRNA(Gln) in concert with ATP hydrolysis. In the absence of the amido acceptor, Glu-tRNA(Gln), the enzyme has basal glutaminase activity that is unaffected by ATP. However, Glu-tRNA(Gln) activates the glutaminase activity of the enzyme about 10-fold; addition of ATP elicits a further 7-fold increase. These enhanced activities mainly result from increases in k(cat) without significant effects on the K(m) for Gln. To determine if ATP binding is sufficient to induce full activation, we tested a variety of ATP analogues for their ability to stimulate tRNA-dependent glutaminase activity. Despite their binding to Glu-AdT, none of the ATP analogues induced glutaminase activation except ATP-gammaS, which stimulates glutaminase activity to the same level as ATP, but without formation of Gln-tRNA(Gln). ATP-gammaS hydrolysis by Glu-AdT is very low in the absence or presence of Glu-tRNA(Gln) and Gln. In contrast, Glu-tRNA(Gln) stimulates basal ATP hydrolysis slightly, but full activation of ATP hydrolysis requires both Gln and Glu-tRNA(Gln). Simultaneous monitoring of ATP or ATP-gammaS hydrolysis and glutaminase and transamidase activities reveals tight coupling among these activities in the presence of ATP, with all three activities waning in concert when Glu-tRNA(Gln) levels become exhausted. ATP-gammaS stimulates the glutaminase activity to an extent similar to that with ATP, but without concomitant transamidase activity and with a very low level of ATP-gammaS hydrolysis. This uncoupling between ATP-gammaS hydrolysis and glutaminase activities suggests that the activation of glutaminase activity by ATP or ATP-gammaS, together with Glu-tRNA(Gln), results either from an allosteric effect due simply to binding of these analogues to the enzyme or from some structural changes that attend ATP or ATP-gammaS hydrolysis.
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Affiliation(s)
- K Y Horiuchi
- Chemical Enzymology and Antimicrobials Departments, DuPont Pharmaceuticals Company, Experimental Station, Wilmington, Delaware 19880, USA.
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