1
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Sundararaman SA, Miller JJ, Daley EC, O'Brien KA, Kasak P, Daniels AM, Edwards RL, Heidel KM, Bague DA, Wilson MA, Koelper AJ, Kourtoglou EC, White AD, August SA, Apple GA, Rouamba RW, Durand AJ, Esteb JJ, Muller FL, Johnson RJ, Hoops GC, Dowd CS, Odom John AR. Prodrug activation in malaria parasites mediated by an imported erythrocyte esterase, acylpeptide hydrolase (APEH). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.30.610542. [PMID: 39257815 PMCID: PMC11383709 DOI: 10.1101/2024.08.30.610542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
The continued emergence of antimalarial drug resistance highlights the need to develop new antimalarial therapies. Unfortunately, new drug development is often hampered by poor drug-like properties of lead compounds. Prodrugging temporarily masks undesirable compound features, improving bioavailability and target penetration. We have found that lipophilic diester prodrugs of phosphonic acid antibiotics, such as fosmidomycin, exhibit significantly higher antimalarial potency than their parent compounds (1). However, the activating enzymes for these prodrugs were unknown. Here, we show that an erythrocyte enzyme, acylpeptide hydrolase (APEH) is the major activating enzyme of multiple lipophilic ester prodrugs. Surprisingly, this enzyme is taken up by the malaria parasite, Plasmodium falciparum, where it localizes to the parasite cytoplasm and retains enzymatic activity. Using a novel fluorogenic ester library, we characterize the structure activity relationship of APEH, and compare it to that of P. falciparum esterases. We show that parasite-internalized APEH plays an important role in the activation of substrates with branching at the alpha carbon, in keeping with its exopeptidase activity. Our findings highlight a novel mechanism for antimicrobial prodrug activation, relying on a host-derived enzyme to yield activation at a microbial target. Mutations in prodrug activating enzymes are a common mechanism for antimicrobial drug resistance (2-4). Leveraging an internalized host enzyme would circumvent this, enabling the design of prodrugs with higher barriers to drug resistance.
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Affiliation(s)
- S A Sundararaman
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - J J Miller
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - E C Daley
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - K A O'Brien
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - P Kasak
- College of Health Professions, Thomas Jefferson University, Philadelphia, PA, USA
| | - A M Daniels
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, USA
| | - R L Edwards
- Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA
- Omniose, Saint Louis, MO, USA
| | - K M Heidel
- Department of Chemistry, George Washington University, 800 22nd Street NW, Washington DC, USA
| | - D A Bague
- Department of Chemistry, George Washington University, 800 22nd Street NW, Washington DC, USA
| | - M A Wilson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - A J Koelper
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - E C Kourtoglou
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - A D White
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - S A August
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - G A Apple
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - R W Rouamba
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - A J Durand
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - J J Esteb
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - F L Muller
- Lindonlight Collective, Houston, TX, USA
| | - R J Johnson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - G C Hoops
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN, USA
| | - C S Dowd
- Department of Chemistry, George Washington University, 800 22nd Street NW, Washington DC, USA
| | - A R Odom John
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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2
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Goss AL, Shudick RE, Johnson RJ. Shifting Mycobacterial Serine Hydrolase Activity Visualized Using Multi-Layer In-Gel Activity Assays. Molecules 2024; 29:3386. [PMID: 39064965 PMCID: PMC11279797 DOI: 10.3390/molecules29143386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
The ability of Mycobacterium tuberculosis to derive lipids from the host, store them intracellularly, and then break them down into energy requires a battery of serine hydrolases. Serine hydrolases are a large, diverse enzyme family with functional roles in dormant, active, and reactivating mycobacterial cultures. To rapidly measure substrate-dependent shifts in mycobacterial serine hydrolase activity, we combined a robust mycobacterial growth system of nitrogen limitation and variable carbon availability with nimble in-gel fluorogenic enzyme measurements. Using this methodology, we rapidly analyzed a range of ester substrates, identified multiple hydrolases concurrently, observed functional enzyme shifts, and measured global substrate preferences. Within every growth condition, mycobacterial hydrolases displayed the full, dynamic range of upregulated, downregulated, and constitutively active hydrolases independent of the ester substrate. Increasing the alkyl chain length of the ester substrate also allowed visualization of distinct hydrolase activity likely corresponding with lipases most responsible for lipid breakdown. The most robust expression of hydrolase activity was observed under the highest stress growth conditions, reflecting the induction of multiple metabolic pathways scavenging for energy to survive under this high stress. The unique hydrolases present under these high-stress conditions could represent novel drug targets for combination treatment with current front-line therapeutics. Combining diverse fluorogenic esters with in-gel activity measurements provides a rapid, customizable, and sensitive detection method for mycobacterial serine hydrolase activity.
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Affiliation(s)
| | | | - R. Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208, USA
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3
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Harris WT, Altieri I, Gieck I, Johnson RJ. A conserved but structurally divergent loop in acyl protein thioesterase 1 regulates its catalytic activity, ligand binding, and folded stability. Proteins 2024; 92:693-704. [PMID: 38179877 DOI: 10.1002/prot.26661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/06/2024]
Abstract
Human acyl protein thioesterases (APTs) catalyze the depalmitoylation of S-acylated proteins attached to the plasma membrane, facilitating reversible cycles of membrane anchoring and detachment. We previously showed that a bacterial APT homologue, FTT258 from the gram-negative pathogen Francisella tularensis, exists in equilibrium between a closed and open state based on the structural dynamics of a flexible loop overlapping its active site. Although the structural dynamics of this loop are not conserved in human APTs, the amino acid sequence of this loop is highly conserved, indicating essential but divergent functions for this loop in human APTs. Herein, we investigated the role of this loop in regulating the catalytic activity, ligand binding, and protein folding of human APT1, a depalmitoylase connected with cancer, immune, and neurological signaling. Using a combination of substitutional analysis with kinetic, structural, and biophysical characterization, we show that even in its divergent structural location in human APT1 that this loop still regulates the catalytic activity of APT1 through contributions to ligand binding and substrate positioning. We confirmed previously known roles for multiple residues (Phe72 and Ile74) in substrate binding and catalysis while adding new roles in substrate selectivity (Pro69), in catalytic stabilization (Asp73 and Ile75), and in transitioning between the membrane binding β-tongue and substrate-binding loops (Trp71). Even conservative substitution of this tryptophan (Trp71) fulcrum led to complete loss of catalytic activity, a 13°C decrease in total protein stability, and drastic drops in ligand affinity, indicating that the combination of the size, shape, and aromaticity of Trp71 are essential to the proper structure of APT1. Mixing buried hydrophobic surface area with contributions to an exposed secondary surface pocket, Trp71 represents a previously unidentified class of essential tryptophans within α/β hydrolase structure and a potential allosteric binding site within human APTs.
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Affiliation(s)
- William Trey Harris
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Isabelle Altieri
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Isabella Gieck
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - R Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
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4
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Schemenauer D, Pool EH, Raynor SN, Ruiz GP, Goehring LM, Koelper AJ, Wilson MA, Durand AJ, Kourtoglou EC, Larsen EM, Lavis LD, Esteb JJ, Hoops GC, Johnson RJ. Sequence and Structural Motifs Controlling the Broad Substrate Specificity of the Mycobacterial Hormone-Sensitive Lipase LipN. ACS OMEGA 2023; 8:13252-13264. [PMID: 37065048 PMCID: PMC10099132 DOI: 10.1021/acsomega.3c00534] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Mycobacterium tuberculosis has a complex life cycle transitioning between active and dormant growth states depending on environmental conditions. LipN (Rv2970c) is a conserved mycobacterial serine hydrolase with regulated catalytic activity at the interface between active and dormant growth conditions. LipN also catalyzes the xenobiotic degradation of a tertiary ester substrate and contains multiple conserved motifs connected with the ability to catalyze the hydrolysis of difficult tertiary ester substrates. Herein, we expanded a library of fluorogenic ester substrates to include more tertiary and constrained esters and screened 33 fluorogenic substrates for activation by LipN, identifying its unique substrate signature. LipN preferred short, unbranched ester substrates, but had its second highest activity against a heteroaromatic five-membered oxazole ester. Oxazole esters are present in multiple mycobacterial serine hydrolase inhibitors but have not been tested widely as ester substrates. Combined structural modeling, kinetic measurements, and substitutional analysis of LipN showcased a fairly rigid binding pocket preorganized for catalysis of short ester substrates. Substitution of diverse amino acids across the binding pocket significantly impacted the folded stability and catalytic activity of LipN with two conserved motifs (HGGGW and GDSAG) playing interconnected, multidimensional roles in regulating its substrate specificity. Together this detailed substrate specificity profile of LipN illustrates the complex interplay between structure and function in mycobacterial hormone-sensitive lipase homologues and indicates oxazole esters as promising inhibitor and substrate scaffolds for mycobacterial hydrolases.
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Affiliation(s)
- Daniel
E. Schemenauer
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Emily H. Pool
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Stephanie N. Raynor
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Gabriela P. Ruiz
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Leah M. Goehring
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Andrew J. Koelper
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Madeleine A. Wilson
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Anthony J. Durand
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Elexi C. Kourtoglou
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Erik M. Larsen
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Luke D. Lavis
- Howard
Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia 20147, United States
| | - John J. Esteb
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - Geoffrey C. Hoops
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
| | - R. Jeremy Johnson
- Department
of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208, United States
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5
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Jia W, Li H, Wang Q, Zheng K, Lin H, Li X, Huang J, Xu L, Dong W, Shu Z. Screening of perhydrolases to optimize glucose oxidase-perhydrolase-in situ chemical oxidation cascade reaction system and its application in melanin decolorization. J Biotechnol 2021; 328:106-114. [PMID: 33485863 DOI: 10.1016/j.jbiotec.2021.01.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 01/02/2021] [Accepted: 01/12/2021] [Indexed: 10/22/2022]
Abstract
A novel glucose oxidase (GOD)-perhydrolase-in situ chemical oxidation (ISCO) cascade reaction system was designed, optimized, and verified the operation feasibility in this research. Among the determined four perhydrolases, acyltransferase from Mycobacterium smegmatis (MsAcT) displayed the highest specific activity for perhydrolysis reaction (76.4 U/mg) and the lowest Km value to hydrogen peroxide (13.9 mmol/L). GOD-MsAcT cascade reaction system also displayed high catalytic efficiency. Under the optimal parameters (50:1 activity unit ratio of GOD to MsAcT, pH 8.0, 50 mmol/L of β-d-glucose, and 15 mmol/L of glyceryl triacetate), the melanin decolorization rate using GOD-MsAcT-ISCO cascade reaction system reached 86.8 %. Kinetics of GOD-MsAcT-ISCO cascade reaction system for melanin decolorization fitted the kinetic model of Boltzmann sigmoid. As a substitutive skin whitening technology, GOD-MsAcT-ISCO cascade reaction system displayed an excellent application prospect.
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Affiliation(s)
- Wenjing Jia
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Huan Li
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Qian Wang
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Kaixuan Zheng
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China; Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Fujian Normal University, Fuzhou, 350117, China
| | - Hong Lin
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Xin Li
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Jianzhong Huang
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China.
| | - Linting Xu
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Wanqian Dong
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China
| | - Zhengyu Shu
- National & Local United Engineering Research Center of Industrial Microbiology and Fermentation Technology, Ministry of Education, Fujian Normal University, Fuzhou, 350117, China; College of Life Sciences, Fujian Normal University (Qishan Campus), Fuzhou, 350117, China; Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Fujian Normal University, Fuzhou, 350117, China.
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6
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Bun JS, Slack MD, Schemenauer DE, Johnson RJ. Comparative analysis of the human serine hydrolase OVCA2 to the model serine hydrolase homolog FSH1 from S. cerevisiae. PLoS One 2020; 15:e0230166. [PMID: 32182256 PMCID: PMC7077851 DOI: 10.1371/journal.pone.0230166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/20/2020] [Indexed: 11/22/2022] Open
Abstract
Over 100 metabolic serine hydrolases are present in humans with confirmed functions in metabolism, immune response, and neurotransmission. Among potentially clinically-relevant but uncharacterized human serine hydrolases is OVCA2, a serine hydrolase that has been linked with a variety of cancer-related processes. Herein, we developed a heterologous expression system for OVCA2 and determined the comprehensive substrate specificity of OVCA2 against two ester substrate libraries. Based on this analysis, OVCA2 was confirmed as a serine hydrolase with a strong preference for long-chain alkyl ester substrates (>10-carbons) and high selectivity against a variety of short, branched, and substituted esters. Substitutional analysis was used to identify the catalytic residues of OVCA2 with a Ser117-His206-Asp179 classic catalytic triad. Comparison of the substrate specificity of OVCA2 to the model homologue FSH1 from Saccharomyces cerevisiae illustrated the tighter substrate selectivity of OVCA2, but their overlapping substrate preference for extended straight-chain alkyl esters. Conformation of the overlapping biochemical properties of OVCA2 and FSH1 was used to model structural information about OVCA2. Together our analysis provides detailed substrate specificity information about a previously, uncharacterized human serine hydrolase and begins to define the biological properties of OVCA2.
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Affiliation(s)
- Jessica S. Bun
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, United States of America
| | - Michael D. Slack
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, United States of America
| | - Daniel E. Schemenauer
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, United States of America
| | - R. Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, United States of America
- * E-mail:
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7
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Wang Y, Le LTHL, Yoo W, Lee CW, Kim KK, Lee JH, Kim TD. Characterization, immobilization, and mutagenesis of a novel cold-active acetylesterase (EaAcE) from Exiguobacterium antarcticum B7. Int J Biol Macromol 2019; 136:1042-1051. [PMID: 31229546 DOI: 10.1016/j.ijbiomac.2019.06.108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/07/2019] [Accepted: 06/15/2019] [Indexed: 12/17/2022]
Abstract
Cold-active enzymes with distinctive properties from a psychrophilic Exiguobacterium antarcticum B7 could be excellent biocatalysts in industrial and biotechnological processes. Here, the characterization, immobilization, and site-directed mutagenesis of a novel cold-active acetylesterase (EaAcE) from E. antarcticum B7 is reported. EaAcE does not belong to any currently known lipase/esterase family, although there are some sequence similarities with family III and V members. Biochemical characterization of EaAcE was carried out using activity staining, mass spectrometry analysis, circular dichroism spectra, freeze-thaw experiments, kinetic analysis, acetic acid release assays, and enantioselectivity determination. Furthermore, immobilization of EaAcE using four different approaches was explored to enhance its thermal stability and recyclability. Based on a homology model of EaAcE, four mutations (F45A, S118A, S141A, and T216A) within the substrate-binding pocket were investigated to elucidate their roles in EaAcE catalysis and substrate specificity. This work has provided invaluable information on the properties of EaAcE, which can now be used to understand the acetylesterase enzyme family.
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Affiliation(s)
- Ying Wang
- Department of Chemistry, College of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Ly Thi Huong Luu Le
- Department of Chemistry, College of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Wanki Yoo
- Department of Chemistry, College of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea; Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Chang Woo Lee
- Unit of Polar Genomics, Korea Polar Research Institute (KOPRI), Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology (UST), Incheon, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Jun Hyuck Lee
- Unit of Polar Genomics, Korea Polar Research Institute (KOPRI), Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology (UST), Incheon, Republic of Korea
| | - T Doohun Kim
- Department of Chemistry, College of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea.
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8
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Mo HM, Xu Y, Yu XW. Improved Soluble Expression and Catalytic Activity of a Thermostable Esterase Using a High-Throughput Screening System Based on a Split-GFP Assembly. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:12756-12764. [PMID: 30411620 DOI: 10.1021/acs.jafc.8b04646] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The thermostable esterase Aaeo1 displays a low expression level and forms a great amount of inclusion bodies in E. coli. Herein, a split-GFP system was established in which the fluorescence intensity exhibited a good linear correlation with the soluble protein expression level and the esterase activity. In the primary high-throughput screening, the mutant library was screened by flow cytometry via detection of a split-GFP reporter. Then, through a secondary screening against esterase activity, two mutants with improved soluble expression and catalytic activity were obtained. The soluble expression of the mutant enzymes in E. coli was improved by 2-fold. The kcat/ Km values of the mutant enzymes were 2-fold higher than that of the parent. We explored the relationship between the amino acid mutations in the two mutants and the enzyme activity. The enzyme activity of mutant I51V-E170D was 4.5 times higher than that of the parent.
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Affiliation(s)
- Hong-Mei Mo
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
| | - Xiao-Wei Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
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9
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Crystal structure and functional characterization of a cold-active acetyl xylan esterase (PbAcE) from psychrophilic soil microbe Paenibacillus sp. PLoS One 2018; 13:e0206260. [PMID: 30379876 PMCID: PMC6209228 DOI: 10.1371/journal.pone.0206260] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/09/2018] [Indexed: 12/27/2022] Open
Abstract
Cold-active acetyl xylan esterases allow for reduced bioreactor heating costs in bioenergy production. Here, we isolated and characterized a cold-active acetyl xylan esterase (PbAcE) from the psychrophilic soil microbe Paenibacillus sp. R4. The enzyme hydrolyzes glucose penta-acetate and xylan acetate, reversibly producing acetyl xylan from xylan, and it shows higher activity at 4°C than at 25°C. We solved the crystal structure of PbAcE at 2.1-Å resolution to investigate its active site and the reason for its low-temperature activity. Structural analysis showed that PbAcE forms a hexamer with a central substrate binding tunnel, and the inter-subunit interactions are relatively weak compared with those of its mesophilic and thermophilic homologs. PbAcE also has a shorter loop and different residue composition in the β4–α3 and β5–α4 regions near the substrate binding site. Flexible subunit movements and different active site loop conformations may enable the strong low-temperature activity and broad substrate specificity of PbAcE. In addition, PbAcE was found to have strong activity against antibiotic compound substrates, such as cefotaxime and 7-amino cephalosporanic acid (7-ACA). In conclusion, the PbAcE structure and our biochemical results provide the first example of a cold-active acetyl xylan esterase and a starting template for structure-based protein engineering.
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10
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White A, Koelper A, Russell A, Larsen EM, Kim C, Lavis LD, Hoops GC, Johnson RJ. Fluorogenic structure activity library pinpoints molecular variations in substrate specificity of structurally homologous esterases. J Biol Chem 2018; 293:13851-13862. [PMID: 30006352 DOI: 10.1074/jbc.ra118.003972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/11/2018] [Indexed: 01/08/2023] Open
Abstract
Cellular esterases catalyze many essential biological functions by performing hydrolysis reactions on diverse substrates. The promiscuity of esterases complicates assignment of their substrate preferences and biological functions. To identify universal factors controlling esterase substrate recognition, we designed a 32-member structure-activity relationship (SAR) library of fluorogenic ester substrates and used this library to systematically interrogate esterase preference for chain length, branching patterns, and polarity to differentiate common classes of esterase substrates. Two structurally homologous bacterial esterases were screened against this library, refining their previously broad overlapping substrate specificity. Vibrio cholerae esterase ybfF displayed a preference for γ-position thioethers and ethers, whereas Rv0045c from Mycobacterium tuberculosis displayed a preference for branched substrates with and without thioethers. We determined that this substrate differentiation was partially controlled by individual substrate selectivity residues Tyr-119 in ybfF and His-187 in Rv0045c; reciprocal substitution of these residues shifted each esterase's substrate preference. This work demonstrates that the selectivity of esterases is tuned based on transition state stabilization, identifies thioethers as an underutilized functional group for esterase substrates, and provides a rapid method for differentiating structural isozymes. This SAR library could have multifaceted future applications, including in vivo imaging, biocatalyst screening, molecular fingerprinting, and inhibitor design.
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Affiliation(s)
- Alex White
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
| | - Andrew Koelper
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
| | - Arielle Russell
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
| | - Erik M Larsen
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
| | - Charles Kim
- the Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia 20147-2439
| | - Luke D Lavis
- the Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia 20147-2439
| | - Geoffrey C Hoops
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
| | - R Jeremy Johnson
- From the Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana 46208-3443 and
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11
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Bassett B, Waibel B, White A, Hansen H, Stephens D, Koelper A, Larsen EM, Kim C, Glanzer A, Lavis LD, Hoops GC, Johnson RJ. Measuring the Global Substrate Specificity of Mycobacterial Serine Hydrolases Using a Library of Fluorogenic Ester Substrates. ACS Infect Dis 2018; 4:904-911. [PMID: 29648787 PMCID: PMC5993602 DOI: 10.1021/acsinfecdis.7b00263] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Among the proteins required for lipid metabolism in Mycobacterium tuberculosis are a significant number of uncharacterized serine hydrolases, especially lipases and esterases. Using a streamlined synthetic method, a library of immolative fluorogenic ester substrates was expanded to better represent the natural lipidomic diversity of Mycobacterium. This expanded fluorogenic library was then used to rapidly characterize the global structure activity relationship (SAR) of mycobacterial serine hydrolases in M. smegmatis under different growth conditions. Confirmation of fluorogenic substrate activation by mycobacterial serine hydrolases was performed using nonspecific serine hydrolase inhibitors and reinforced the biological significance of the SAR. The hydrolases responsible for the global SAR were then assigned using gel-resolved activity measurements, and these assignments were used to rapidly identify the relative substrate specificity of previously uncharacterized mycobacterial hydrolases. These measurements provide a global SAR of mycobacterial hydrolase activity, a picture of cycling hydrolase activity, and a detailed substrate specificity profile for previously uncharacterized hydrolases.
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Affiliation(s)
- Braden Bassett
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Brent Waibel
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Alex White
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Heather Hansen
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Dominique Stephens
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Andrew Koelper
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Erik M. Larsen
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Charles Kim
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Dr., Ashburn, VA 20147-2439 (USA)
| | - Adam Glanzer
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - Luke D. Lavis
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Dr., Ashburn, VA 20147-2439 (USA)
| | - Geoffrey C. Hoops
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
| | - R. Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208-3443 (USA)
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12
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Smith MA, Phillips WK, Rabin PL, Johnson RJ. A dynamic loop provides dual control over the catalytic and membrane binding activity of a bacterial serine hydrolase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:925-932. [PMID: 29857162 DOI: 10.1016/j.bbapap.2018.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/11/2018] [Accepted: 05/24/2018] [Indexed: 10/16/2022]
Abstract
The bacterial acyl protein thioesterase (APT) homologue FTT258 from the gram-negative pathogen Francisella tularensis exists in equilibrium between a closed and open state. Interconversion between these two states is dependent on structural rearrangement of a dynamic loop overlapping its active site. The dynamics and structural properties of this loop provide a simple model for how the catalytic activity of FTT258 could be spatiotemporally regulated within the cell. Herein, we characterized the dual roles of this dynamic loop in controlling its catalytic and membrane binding activity. Using a comprehensive library of loop variants, we determined the relative importance of each residue in the loop to these two biological functions. For the catalytic activity, a centrally located tryptophan residue (Trp66) was essential, with the resulting alanine variant showing complete ablation of enzyme activity. Detailed analysis of Trp66 showed that its hydrophobicity in combination with spatial arrangement defined its essential role in catalysis. Substitution of other loop residues congregated along the N-terminal side of the loop also significantly impacted catalytic activity, indicating a critical role for this loop in controlling catalytic activity. For membrane binding, the centrally located hydrophobic residues played a surprising minor role in membrane binding. Instead general electrostatic interactions regulated membrane binding with positively charged residues bracketing the dynamic loop controlling membrane binding. Overall for FTT258, this dynamic loop dually controlled its biological activities through distinct residues within the loop and this regulation provides a new model for the spatiotemporal control over FTT258 and potentially homologous APT function.
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Affiliation(s)
- Mackenzie A Smith
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN 46208, USA
| | - Whitney K Phillips
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN 46208, USA
| | - Perry L Rabin
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN 46208, USA
| | - R Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN 46208, USA.
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13
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Adesioye FA, Makhalanyane TP, Vikram S, Sewell BT, Schubert WD, Cowan DA. Structural Characterization and Directed Evolution of a Novel Acetyl Xylan Esterase Reveals Thermostability Determinants of the Carbohydrate Esterase 7 Family. Appl Environ Microbiol 2018; 84:e02695-17. [PMID: 29453256 PMCID: PMC5881061 DOI: 10.1128/aem.02695-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/26/2018] [Indexed: 02/04/2023] Open
Abstract
A hot desert hypolith metagenomic DNA sequence data set was screened in silico for genes annotated as acetyl xylan esterases (AcXEs). One of the genes identified encoded an ∼36-kDa protein (Axe1NaM1). The synthesized gene was cloned and expressed, and the resulting protein was purified. NaM1 was optimally active at pH 8.5 and 30°C and functionally stable at salt concentrations of up to 5 M. The specific activity and catalytic efficiency were 488.9 U mg-1 and 3.26 × 106 M-1 s-1, respectively. The crystal structure of wild-type NaM1 was solved at a resolution of 2.03 Å, and a comparison with the structures and models of more thermostable carbohydrate esterase 7 (CE7) family enzymes and variants of NaM1 from a directed evolution experiment suggests that reduced side-chain volume of protein core residues is relevant to the thermal stability of NaM1. Surprisingly, a single point mutation (N96S) not only resulted in a simultaneous improvement in thermal stability and catalytic efficiency but also increased the acyl moiety substrate range of NaM1.IMPORTANCE AcXEs belong to nine carbohydrate esterase families (CE1 to CE7, CE12, and CE16), of which CE7 enzymes possess a unique and narrow specificity for acetylated substrates. All structurally characterized members of this family are moderately to highly thermostable. The crystal structure of a novel, mesophilic CE7 AcXE (Axe1NaM1), from a soil metagenome, provides a basis for comparisons with thermostable CE7 enzymes. Using error-prone PCR and site-directed mutagenesis, we enhanced both the stability and activity of the mesophilic AcXE. With comparative structural analyses, we have also identified possible thermal stability determinants. These are valuable for understanding the thermal stability of enzymes within this family and as a guide for future protein engineering of CE7 and other α/β hydrolase enzymes.
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Affiliation(s)
- Fiyinfoluwa A Adesioye
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Pretoria, South Africa
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Pretoria, South Africa
| | - Surendra Vikram
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Pretoria, South Africa
| | - Bryan T Sewell
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Pretoria, South Africa
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14
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Singh MK, Shivakumaraswamy S, Gummadi SN, Manoj N. Role of an N-terminal extension in stability and catalytic activity of a hyperthermostable α/β hydrolase fold esterase. Protein Eng Des Sel 2017; 30:559-570. [PMID: 28967962 DOI: 10.1093/protein/gzx049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/25/2017] [Indexed: 12/15/2022] Open
Abstract
The carbohydrate esterase family 7 (CE7) enzymes catalyze the deacetylation of acetyl esters of a broad range of alcohols and is unique in its activity towards cephalosporin C. The CE7 fold contains a conserved N-terminal extension that distinguishes it from the canonical α/β hydrolase fold. The hexameric quaternary structure indicates that the N-terminus may affect activity and specificity by controlling access of substrates to the buried active sites via an entrance tunnel. In this context, we characterized the catalytic parameters, conformation and thermal stability of two truncation variants lacking four and ten residues of the N-terminal region of the hyperthermostable Thermotoga maritima CE7 acetyl esterase (TmAcE). The truncations did not affect the secondary structure or the fold but modulated the oligomerization dynamics. A modest increase was observed in substrate specificity for acetylated xylose compared with acetylated glucose. A drastic reduction of ~30-40°C in the optimum temperature for activity of the variants indicated lower thermal stability. The loss of hyperthermostability appears to be an indirect effect associated with an increase in the conformational flexibility of an otherwise rigid neighboring loop containing a catalytic triad residue. The results suggest that the N-terminal extension was evolutionarily selected to preserve the stability of the enzyme.
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Affiliation(s)
- Mrityunjay K Singh
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Indian Institute of Technology Madras, Chennai 600036, India
| | - Santosh Shivakumaraswamy
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Indian Institute of Technology Madras, Chennai 600036, India
| | - Sathyanarayana N Gummadi
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Indian Institute of Technology Madras, Chennai 600036, India
| | - Narayanan Manoj
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences Indian Institute of Technology Madras, Chennai 600036, India
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15
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Remarkable reactivity of alkoxide/acetato-bridged binuclear copper(II) complex as artificial carboxylesterase. J Biol Inorg Chem 2017; 22:625-635. [PMID: 28364223 DOI: 10.1007/s00775-017-1456-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/28/2017] [Indexed: 10/19/2022]
Abstract
Bromo-containing binuclear Schiff base copper(II) complex, Cu2L(OAc), with an alkoxo/acetato-bridged moiety was employed as a model of carboxylesterases to promote the hydrolytic cleavage of p-nitrophenyl picolinate (PNPP). Furthermore, the reactivity of a mononuclear complex (CuHL) was evaluated for comparing it with that of binuclear one. The results reveal that the as-prepared binuclear Cu2L(OAc) efficiently accelerated the hydrolysis of PNPP, giving rise to excess four orders of magnitude rate enhancement in contrast to the un-catalyzed reaction. Cu2L(OAc) represented an enzyme-like bell-shaped pH-responsive kinetic behavior. Moreover, the binuclear one is more reactive than its mononuclear analogue (CuHL) by two orders of magnitude. The total efficiency of Cu2L(OAc) is about 61-fold than that of its mononuclear analogue, CuHL. In addition, a contrast experiment reveals that binuclear Cu2L(OAc) displayed good activity in the hydrolysis of PNPP as well another active ester, i.e., S-2-benzothiazolyl 2-amino-alpha-(methoxyimino)-4-thiazolethiolacetate (AE-active ester). Noteworthyly, it was found that mononuclear one inspired more obvious rate enhancement in the hydrolysis of AE-active ester relative to PNPP hydrolysis. The estimated pK a1 of bound water on the binuclear Cu2L(OAc) using second derivative method (SDM) is relatively smaller than that for CuHL by a gap of about 0.8 pK unit, which facilitates the hydrolysis of PNPP. Four orders of magnitude rate enhancement was observed for the catalytic hydrolysis of p-nitrophenyl picolinate (PNPP) by one μ-alkoxide/acetato-bridged binuclear copper(II) complex under physiological conditions. Substrate specificity of the resulting binuclear complexes was observed for the hydrolysis of PNPP and AE-active ester.
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16
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Singh MK, Manoj N. Structural role of a conserved active sitecisproline in theThermotoga maritimaacetyl esterase from the carbohydrate esterase family 7. Proteins 2017; 85:694-708. [DOI: 10.1002/prot.25249] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/17/2016] [Accepted: 01/04/2017] [Indexed: 01/24/2023]
Affiliation(s)
- Mrityunjay K. Singh
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 Tamil Nadu India
| | - Narayanan Manoj
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 Tamil Nadu India
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17
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McKary MG, Abendroth J, Edwards TE, Johnson RJ. Structural Basis for the Strict Substrate Selectivity of the Mycobacterial Hydrolase LipW. Biochemistry 2016; 55:7099-7111. [PMID: 27936614 DOI: 10.1021/acs.biochem.6b01057] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complex life cycle of Mycobacterium tuberculosis requires diverse energy mobilization and utilization strategies facilitated by a battery of lipid metabolism enzymes. Among lipid metabolism enzymes, the Lip family of mycobacterial serine hydrolases is essential to lipid scavenging, metabolic cycles, and reactivation from dormancy. On the basis of the homologous rescue strategy for mycobacterial drug targets, we have characterized the three-dimensional structure of full length LipW from Mycobacterium marinum, the first structure of a catalytically active Lip family member. LipW contains a deep, expansive substrate-binding pocket with only a narrow, restrictive active site, suggesting tight substrate selectivity for short, unbranched esters. Structural alignment reinforced this strict substrate selectivity of LipW, as the binding pocket of LipW aligned most closely with the bacterial acyl esterase superfamily. Detailed kinetic analysis of two different LipW homologues confirmed this strict substrate selectivity, as each homologue selected for unbranched propionyl ester substrates, irrespective of the alcohol portion of the ester. Using comprehensive substitutional analysis across the binding pocket, the strict substrate selectivity of LipW for propionyl esters was assigned to a narrow funnel in the acyl-binding pocket capped by a key hydrophobic valine residue. The polar, negatively charged alcohol-binding pocket also contributed to substrate orientation and stabilization of rotameric states in the catalytic serine. Together, the structural, enzymatic, and substitutional analyses of LipW provide a connection between the structure and metabolic properties of a Lip family hydrolase that refines its biological function in active and dormant tuberculosis infection.
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Affiliation(s)
- Magy G McKary
- Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States
| | - Jan Abendroth
- Beryllium Discovery Corporation, Seattle Structural Genomics Center for Infectious Disease (SSGCID) , 7869 Northeast Day Road West, Bainbridge Island, Washington 98110, United States
| | - Thomas E Edwards
- Beryllium Discovery Corporation, Seattle Structural Genomics Center for Infectious Disease (SSGCID) , 7869 Northeast Day Road West, Bainbridge Island, Washington 98110, United States
| | - R Jeremy Johnson
- Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States
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18
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The unusual substrate specificity of a virulence associated serine hydrolase from the highly toxic bacterium, Francisella tularensis. Biochem Biophys Rep 2016; 7:415-422. [PMID: 28955933 PMCID: PMC5613637 DOI: 10.1016/j.bbrep.2016.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 12/26/2022] Open
Abstract
Francisella tularensis is the causative agent of the highly, infectious disease, tularemia. Amongst the genes identified as essential to the virulence of F. tularensis was the proposed serine hydrolase FTT0941c. Herein, we purified FTT0941c to homogeneity and then characterized the folded stability, enzymatic activity, and substrate specificity of FTT0941c. Based on phylogenetic analysis, FTT0941c was classified within a divergent Francisella subbranch of the bacterial hormone sensitive lipase (HSL) superfamily, but with the conserved sequence motifs of a bacterial serine hydrolase. FTT0941c showed broad hydrolase activity against diverse libraries of ester substrates, including significant hydrolytic activity across alkyl ester substrates from 2 to 8 carbons in length. Among a diverse library of fluorogenic substrates, FTT0941c preferred α-cyclohexyl ester substrates, matching with the substrate specificity of structural homologues and the broad open architecture of its modeled binding pocket. By substitutional analysis, FTT0941c was confirmed to have a classic catalytic triad of Ser115, His278, and Asp248 and to remain thermally stable even after substitution. Its overall substrate specificity profile, divergent phylogenetic homology, and preliminary pathway analysis suggested potential biological functions for FTT0941c in diverse metabolic degradation pathways in F. tularensis. FTT0941c is an unstudied virulence associated hydrolase from F. tularensis (74). Classified as a bacterial HSL enzyme within a unique subclade of Francisella (85). Broad substrate specificity for alkyl, unsaturated, tertiary, and cyclic esters (79). Distinct substrate selectivity for α-cyclohexyl esters (54). Proposed metabolic role in cyclohexyl and benzoate ester hydrolysis pathways (76).
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19
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An extended loop in CE7 carbohydrate esterase family is dispensable for oligomerization but required for activity and thermostability. J Struct Biol 2016; 194:434-45. [DOI: 10.1016/j.jsb.2016.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/07/2016] [Accepted: 04/13/2016] [Indexed: 11/20/2022]
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20
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Singh MK, Manoj N. Crystal structure of Thermotoga maritima acetyl esterase complex with a substrate analog: Insights into the distinctive substrate specificity in the CE7 carbohydrate esterase family. Biochem Biophys Res Commun 2016; 476:63-8. [PMID: 27181355 DOI: 10.1016/j.bbrc.2016.05.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 05/11/2016] [Indexed: 11/27/2022]
Abstract
The carbohydrate esterase family 7 (CE7) members are acetyl esterases that possess unusual substrate specificity for cephalosporin C and 7-amino-cephalosporanic acid. This family containing the α/β hydrolase fold has a distinctive substrate profile that allows it to carry out hydrolysis of esters containing diverse alcohol moieties while maintaining narrow specificity for an acetate ester. Here we investigate the structural basis of this preference for small acyl groups using the crystal structure of the thermostable Thermotoga maritima CE7 acetyl esterase (TmAcE) complexed with a non-cognate substrate analog. The structure determined at 1.86 Å resolution provides direct evidence for the location of the largely hydrophobic and rigid substrate binding pocket in this family. Furthermore, a three-helix insertion domain near the catalytic machinery shapes the substrate binding site. The structure reveals two residues (Pro228 and Ile276) which constitute a hydrophobic rigid binding surface for the acyl group of the ester and thus restricts the size of the acyl group that be accommodated. In combination with previous literature on kinetic properties of the enzyme, our studies suggest that these residues determine the unique specificity of the TmAcE for short straight chain esters. The structure provides a template for focused attempts to engineer the CE7 enzymes for enhanced stability, selectivity or activity for biocatalytic applications.
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Affiliation(s)
- Mrityunjay K Singh
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Narayanan Manoj
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India.
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21
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Kowalski JR, Hoops GC, Johnson RJ. Implementation of a Collaborative Series of Classroom-Based Undergraduate Research Experiences Spanning Chemical Biology, Biochemistry, and Neurobiology. CBE LIFE SCIENCES EDUCATION 2016; 15:15/4/ar55. [PMID: 27810870 PMCID: PMC5132352 DOI: 10.1187/cbe.16-02-0089] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 08/23/2016] [Indexed: 05/14/2023]
Abstract
Classroom undergraduate research experiences (CUREs) provide students access to the measurable benefits of undergraduate research experiences (UREs). Herein, we describe the implementation and assessment of a novel model for cohesive CUREs focused on central research themes involving faculty research collaboration across departments. Specifically, we implemented three collaborative CUREs spanning chemical biology, biochemistry, and neurobiology that incorporated faculty members' research interests and revolved around the central theme of visualizing biological processes like Mycobacterium tuberculosis enzyme activity and neural signaling using fluorescent molecules. Each CURE laboratory involved multiple experimental phases and culminated in novel, open-ended, and reiterative student-driven research projects. Course assessments showed CURE participation increased students' experimental design skills, attitudes and confidence about research, perceived understanding of the scientific process, and interest in science, technology, engineering, and mathematics disciplines. More than 75% of CURE students also engaged in independent scientific research projects, and faculty CURE contributors saw substantial increases in research productivity, including increased undergraduate student involvement and academic outputs. Our collaborative CUREs demonstrate the advantages of multicourse CUREs for achieving increased faculty research productivity and traditional CURE-associated student learning and attitude gains. Our collaborative CURE design represents a novel CURE model for ongoing laboratory reform that benefits both faculty and students.
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Affiliation(s)
- Jennifer R Kowalski
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208
| | - Geoffrey C Hoops
- Department of Chemistry, Butler University, Indianapolis, IN 46208
| | - R Jeremy Johnson
- Department of Chemistry, Butler University, Indianapolis, IN 46208
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22
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Mokoena N, Mathiba K, Tsekoa T, Steenkamp P, Rashamuse K. Application of termite hindgut metagenome derived carboxyl ester hydrolases in the modification of cephalosporin substrates. Biochem Biophys Rep 2015; 4:44-51. [PMID: 29124186 PMCID: PMC5668906 DOI: 10.1016/j.bbrep.2015.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 08/20/2015] [Accepted: 08/24/2015] [Indexed: 11/26/2022] Open
Abstract
In the pharmaceutical industry, de-acetylated cephalosporins are highly valuable starting materials for producing semi-synthetic β-lactam antibiotics. In this study a fosmid metagenome library from termite hindgut symbionts was screened for carboxyl ester hydrolases capable of de-acetylating cephalosporins. Recombinant Escherichia coli clones with esterolytic phenotypes on tributyrin agar plates were selected and further tested for de-acetylating activity against Cephalothin and 7-aminocephalosporanic acid (7-ACA). Two clones displaying de-acetylating activity were sequenced and the corresponding two carboxyl ester hydrolase encoding genes (axeA and axeB) belonging to the carbohydrate esterase family 7 (CE7) were identified. The primary structure of both the axeA and axeB revealed the presence of G-X-S-X-G sequence motif and respective subunit molecular masses of 40 kDa. In addition to de-acetylating cephalosporin based molecules, the two enzymes were also shown to be true esterases based on their preferences for short chain length fatty acid esters. Esterases (AxeA and AxeB) contained classical G-X-S-x-G motif and showed deacetylating activities against cephalosporin substrates. AxeA and AxeB can be useful in the biocatalytic modification of cephalosporin molecules.
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Affiliation(s)
- Nobalanda Mokoena
- CSIR Biosciences, Biomanufacturing Technology Competence Area, Brummeria, Pretoria 0001, South Africa
| | - Kgama Mathiba
- CSIR Biosciences, Biomanufacturing Technology Competence Area, Brummeria, Pretoria 0001, South Africa
| | - Tsepo Tsekoa
- CSIR Biosciences, Biomanufacturing Technology Competence Area, Brummeria, Pretoria 0001, South Africa
| | - Paul Steenkamp
- CSIR Biosciences, Biomanufacturing Technology Competence Area, Brummeria, Pretoria 0001, South Africa.,Department of Biochemistry, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
| | - Konanani Rashamuse
- CSIR Biosciences, Biomanufacturing Technology Competence Area, Brummeria, Pretoria 0001, South Africa
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23
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Kim K, Ryu BH, Kim SS, An DR, Ngo TD, Pandian R, Kim KK, Kim TD. Structural and biochemical characterization of a carbohydrate acetylesterase from Sinorhizobium meliloti 1021. FEBS Lett 2015; 589:117-122. [PMID: 25436419 DOI: 10.1016/j.febslet.2014.11.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 12/29/2022]
Abstract
In many microorganisms, carbohydrate acetylesterases remove the acetyl groups from various types of carbohydrates. Sm23 from Sinorhizobium meliloti is a putative member of carbohydrate esterase family 3 (CE3) in the CAZy classification system. Here, we determined the crystal structure of Sm23 at 1.75 Å resolution and investigated functional properties using biochemical methods. Furthermore, immobilized Sm23 exhibited improved stability compared with soluble Sm23, which can be used for the design of plant cell wall degrading-systems.
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Affiliation(s)
- Kyungmin Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Bum Han Ryu
- Department of Applied Chemistry and Biological Engineering, College of Engineering, Ajou University, Suwon 443-741, Republic of Korea
| | - Sung Soo Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Deu Rae An
- Department of Applied Chemistry and Biological Engineering, College of Engineering, Ajou University, Suwon 443-741, Republic of Korea
| | - Tri Duc Ngo
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Ramesh Pandian
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea.
| | - T Doohun Kim
- Department of Applied Chemistry and Biological Engineering, College of Engineering, Ajou University, Suwon 443-741, Republic of Korea.
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24
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Lukowski JK, Savas CP, Gehring AM, McKary MG, Adkins CT, Lavis LD, Hoops GC, Johnson RJ. Distinct substrate selectivity of a metabolic hydrolase from Mycobacterium tuberculosis. Biochemistry 2014; 53:7386-95. [PMID: 25354081 DOI: 10.1021/bi501108u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The transition between dormant and active Mycobacterium tuberculosis infection requires reorganization of its lipid metabolism and activation of a battery of serine hydrolase enzymes. Among these serine hydrolases, Rv0045c is a mycobacterial-specific serine hydrolase with limited sequence homology outside mycobacteria but structural homology to divergent bacterial hydrolase families. Herein, we determined the global substrate specificity of Rv0045c against a library of fluorogenic hydrolase substrates, constructed a combined experimental and computational model for its binding pocket, and performed comprehensive substitutional analysis to develop a structural map of its binding pocket. Rv0045c showed strong substrate selectivity toward short, straight chain alkyl esters with the highest activity toward four atom chains. This strong substrate preference was maintained through the combined action of residues in a flexible loop connecting the cap and α/β hydrolase domains and in residues close to the catalytic triad. Two residues bracketing the substrate-binding pocket (Gly90 and His187) were essential to maintaining the narrow substrate selectivity of Rv0045c toward various acyl ester substituents, as independent conversion of these residues significantly increased its catalytic activity and broadened its substrate specificity. Focused saturation mutagenesis of position 187 implicated this residue, as the differentiation point between the substrate specificity of Rv0045c and the structurally homologous ybfF hydrolase family. Insertion of the analogous tyrosine residue from ybfF hydrolases into Rv0045c increased the catalytic activity of Rv0045 by over 20-fold toward diverse ester substrates. The unique binding pocket structure and selectivity of Rv0045c provide molecular indications of its biological role and evidence for expanded substrate diversity in serine hydrolases from M. tuberculosis.
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Affiliation(s)
- Jessica K Lukowski
- Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States
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Yan QJ, Yang SQ, Duan XJ, Xu HB, Liu Y, Jiang ZQ. Characterization of a novel hormone-sensitive lipase family esterase from Rhizomucor miehei with tertiary alcohol hydrolysis activity. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2014.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Blumer-Schuette SE, Brown SD, Sander KB, Bayer EA, Kataeva I, Zurawski JV, Conway JM, Adams MWW, Kelly RM. Thermophilic lignocellulose deconstruction. FEMS Microbiol Rev 2014; 38:393-448. [DOI: 10.1111/1574-6976.12044] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 08/20/2013] [Accepted: 08/28/2013] [Indexed: 11/28/2022] Open
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Ellis EE, Adkins CT, Galovska NM, Lavis LD, Johnson RJ. Decoupled roles for the atypical, bifurcated binding pocket of the ybfF hydrolase. Chembiochem 2013; 14:1134-44. [PMID: 23670977 DOI: 10.1002/cbic.201300085] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Indexed: 11/08/2022]
Abstract
Serine hydrolases have diverse intracellular substrates, biological functions, and structural plasticity, and are thus important for biocatalyst design. Amongst serine hydrolases, the recently described ybfF enzyme family are promising novel biocatalysts with an unusual bifurcated substrate-binding cleft and the ability to recognize commercially relevant substrates. We characterized in detail the substrate selectivity of a novel ybfF enzyme from Vibrio cholerae (Vc-ybfF) by using a 21-member library of fluorogenic ester substrates. We assigned the roles of the two substrate-binding clefts in controlling the substrate selectivity and folded stability of Vc-ybfF by comprehensive substitution analysis. The overall substrate preference of Vc-ybfF was for short polar chains, but it retained significant activity with a range of cyclic and extended esters. This broad substrate specificity combined with the substitutional analysis demonstrates that the larger binding cleft controls the substrate specificity of Vc-ybfF. Key selectivity residues (Tyr116, Arg120, Tyr209) are also located at the larger binding pocket and control the substrate specificity profile. In the structure of ybfF the narrower binding cleft contains water molecules prepositioned for hydrolysis, but based on substitution this cleft showed only minimal contribution to catalysis. Instead, the residues surrounding the narrow binding cleft and at the entrance to the binding pocket contributed significantly to the folded stability of Vc-ybfF. The relative contributions of each cleft of the binding pocket to the catalytic activity and folded stability of Vc-ybfF provide a valuable map for designing future biocatalysts based on the ybfF scaffold.
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Affiliation(s)
- Elizabeth E Ellis
- Department of Chemistry, Butler University, 4600 Sunset Ave, Indianapolis, IN 46208-3443, USA
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28
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Filippova EV, Weston LA, Kuhn ML, Geissler B, Gehring AM, Armoush N, Adkins CT, Minasov G, Dubrovska I, Shuvalova L, Winsor JR, Lavis LD, Satchell KJF, Becker DP, Anderson WF, Johnson RJ. Large scale structural rearrangement of a serine hydrolase from Francisella tularensis facilitates catalysis. J Biol Chem 2013; 288:10522-35. [PMID: 23430251 DOI: 10.1074/jbc.m112.446625] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tularemia is a deadly, febrile disease caused by infection by the gram-negative bacterium, Francisella tularensis. Members of the ubiquitous serine hydrolase protein family are among current targets to treat diverse bacterial infections. Herein we present a structural and functional study of a novel bacterial carboxylesterase (FTT258) from F. tularensis, a homologue of human acyl protein thioesterase (hAPT1). The structure of FTT258 has been determined in multiple forms, and unexpectedly large conformational changes of a peripheral flexible loop occur in the presence of a mechanistic cyclobutanone ligand. The concomitant changes in this hydrophobic loop and the newly exposed hydrophobic substrate binding pocket suggest that the observed structural changes are essential to the biological function and catalytic activity of FTT258. Using diverse substrate libraries, site-directed mutagenesis, and liposome binding assays, we determined the importance of these structural changes to the catalytic activity and membrane binding activity of FTT258. Residues within the newly exposed hydrophobic binding pocket and within the peripheral flexible loop proved essential to the hydrolytic activity of FTT258, indicating that structural rearrangement is required for catalytic activity. Both FTT258 and hAPT1 also showed significant association with liposomes designed to mimic bacterial or human membranes, respectively, even though similar structural rearrangements for hAPT1 have not been reported. The necessity for acyl protein thioesterases to have maximal catalytic activity near the membrane surface suggests that these conformational changes in the protein may dually regulate catalytic activity and membrane association in bacterial and human homologues.
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Affiliation(s)
- Ekaterina V Filippova
- Center for Structural Genomics of Infectious Diseases and the Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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