1
|
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.
Collapse
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
| |
Collapse
|
2
|
Mikesell LD, Livinghouse T. Base-Catalyzed Phenol-Mannich Condensation of Preformed Cesium Iminodiacetate. The Direct Synthesis of Calcein Blue AM and Related Acyloxymethyl Esters. J Org Chem 2023; 88:12064-12068. [PMID: 37556402 DOI: 10.1021/acs.joc.3c00155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
A rapid and highly practical one-flask procedure for the positionally selective preparation of (acyloxy)methyl N-(2-hydroxybenzyl)iminodiacetate and related diesters from iminodiacetic acid and phenols is described. The key to this multicomponent phenol-Mannich condensation resides in the use of cesium iminodiacetate as the reaction partner. This protocol has been applied in an unusually direct synthesis of the intracellular fluorescent dye Calcein blue AM, for which scant experimental and spectroscopic data are presently available.
Collapse
Affiliation(s)
- Logan D Mikesell
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Tom Livinghouse
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Bowles IE, Pool EH, Lancaster BS, Lawson EK, Savas CP, Kartje ZJ, Severinac L, Cho DH, Macbeth MR, Johnson RJ, Hoops GC. Transition metal cation inhibition of Mycobacterium tuberculosis esterase RV0045C. Protein Sci 2021; 30:1554-1565. [PMID: 33914998 DOI: 10.1002/pro.4089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/16/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022]
Abstract
Mycobacterium tuberculosis virulence is highly metal-dependent with metal availability modulating the shift from the dormant to active states of M. tuberculosis infection. Rv0045c from M. tuberculosis is a proposed metabolic serine hydrolase whose folded stability is dependent on divalent metal concentration. Herein, we measured the divalent metal inhibition profile of the enzymatic activity of Rv0045c and found specific divalent transition metal cations (Cu2+ ≥ Zn2+ > Ni2+ > Co2+ ) strongly inhibited its enzymatic activity. The metal cations bind allosterically, largely affecting values for kcat rather than KM . Removal of the artificial N-terminal 6xHis-tag did not change the metal-dependent inhibition, indicating that the allosteric inhibition site is native to Rv0045c. To isolate the site of this allosteric regulation in Rv0045c, the structures of Rv0045c were determined at 1.8 Å and 2.0 Å resolution in the presence and absence of Zn2+ with each structure containing a previously unresolved dynamic loop spanning the binding pocket. Through the combination of structural analysis with and without zinc and targeted mutagenesis, this metal-dependent inhibition was traced to multiple chelating residues (H202A/E204A) on a flexible loop, suggesting dynamic allosteric regulation of Rv0045c by divalent metals. Although serine hydrolases like Rv0045c are a large and diverse enzyme superfamily, this is the first structural confirmation of allosteric regulation of their enzymatic activity by divalent metals.
Collapse
Affiliation(s)
- Isobel E Bowles
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Emily H Pool
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Benjamin S Lancaster
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Emily K Lawson
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Christopher P Savas
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Zach J Kartje
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Luke Severinac
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - David H Cho
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Mark R Macbeth
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - R Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| | - Geoffrey C Hoops
- Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA
| |
Collapse
|
5
|
Miguel-Ruano V, Rivera I, Rajkovic J, Knapik K, Torrado A, Otero JM, Beneventi E, Becerra M, Sánchez-Costa M, Hidalgo A, Berenguer J, González-Siso MI, Cruces J, Rúa ML, Hermoso JA. Biochemical and Structural Characterization of a novel thermophilic esterase EstD11 provide catalytic insights for the HSL family. Comput Struct Biotechnol J 2021; 19:1214-1232. [PMID: 33680362 PMCID: PMC7905190 DOI: 10.1016/j.csbj.2021.01.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 12/31/2022] Open
Abstract
A novel esterase, EstD11, has been discovered in a hot spring metagenomic library. It is a thermophilic and thermostable esterase with an optimum temperature of 60°C. A detailed substrate preference analysis of EstD11 was done using a library of chromogenic ester substrate that revealed the broad substrate specificity of EstD11 with significant measurable activity against 16 substrates with varied chain length, steric hindrance, aromaticity and flexibility of the linker between the carboxyl and the alcohol moiety of the ester. The tridimensional structures of EstD11 and the inactive mutant have been determined at atomic resolutions. Structural and bioinformatic analysis, confirm that EstD11 belongs to the family IV, the hormone-sensitive lipase (HSL) family, from the α/β-hydrolase superfamily. The canonical α/β-hydrolase domain is completed by a cap domain, composed by two subdomains that can unmask of the active site to allow the substrate to enter. Eight crystallographic complexes were solved with different substrates and reaction products that allowed identification of the hot-spots in the active site underlying the specificity of the protein. Crystallization and/or incubation of EstD11 at high temperature provided unique information on cap dynamics and a first glimpse of enzymatic activity in vivo. Very interestingly, we have discovered a unique Met zipper lining the active site and the cap domains that could be essential in pivotal aspects as thermo-stability and substrate promiscuity in EstD11.
Collapse
Key Words
- CHCA, cyclohexane carboxylic acid
- CMC, critical micellar concentration
- CV, column volume
- Crystal structure
- DMSO, dimethyl sulfoxide
- DSF, Differential scanning fluorimetry
- Enzyme-substrate complex
- FLU, fluorescein
- HSL, hormone-sensitive lipase
- LDAO, N,N-dimethyldodecylamine N-oxide
- MNP, methyl-naproxen
- Metagenomic
- NP, naproxen
- PPL, Porcine Pancreatic Lipase
- Thermophilic esterase
- pNP, 4-nitrophenol
- α/β hydrolase fold
Collapse
Affiliation(s)
- Vega Miguel-Ruano
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry “Rocasolano”, Spanish National Research Council (CSIC), Madrid, Spain
| | - Ivanna Rivera
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry “Rocasolano”, Spanish National Research Council (CSIC), Madrid, Spain
| | - Jelena Rajkovic
- Biochemistry Laboratory, CITACA-Agri-Food Research and Transfer Cluster, Campus Auga, University of Vigo, Ourense, Spain
| | - Kamila Knapik
- EXPRELA Group, University A Coruña, Science Faculty, Advanced Scientific Research Center (CICA), A Coruña, Spain
| | - Ana Torrado
- Biochemistry Laboratory, CITACA-Agri-Food Research and Transfer Cluster, Campus Auga, University of Vigo, Ourense, Spain
| | | | | | - Manuel Becerra
- EXPRELA Group, University A Coruña, Science Faculty, Advanced Scientific Research Center (CICA), A Coruña, Spain
| | - Mercedes Sánchez-Costa
- Department of Molecular Biology, Center for Molecular Biology “Severo Ochoa” (UAM-CSIC), Autonomous University of Madrid, Madrid, Spain
| | - Aurelio Hidalgo
- Department of Molecular Biology, Center for Molecular Biology “Severo Ochoa” (UAM-CSIC), Autonomous University of Madrid, Madrid, Spain
| | - José Berenguer
- Department of Molecular Biology, Center for Molecular Biology “Severo Ochoa” (UAM-CSIC), Autonomous University of Madrid, Madrid, Spain
| | - María-Isabel González-Siso
- EXPRELA Group, University A Coruña, Science Faculty, Advanced Scientific Research Center (CICA), A Coruña, Spain
| | | | - María L. Rúa
- Biochemistry Laboratory, CITACA-Agri-Food Research and Transfer Cluster, Campus Auga, University of Vigo, Ourense, Spain
| | - Juan A. Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry “Rocasolano”, Spanish National Research Council (CSIC), Madrid, Spain
| |
Collapse
|
6
|
Yoo W, Kim B, Jeon S, Kim KK, Kim TD. Identification, characterization, and immobilization of a novel YbfF esterase from Halomonas elongata. Int J Biol Macromol 2020; 165:1139-1148. [PMID: 33031847 DOI: 10.1016/j.ijbiomac.2020.09.247] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/28/2020] [Accepted: 09/28/2020] [Indexed: 12/19/2022]
Abstract
The YbfF esterase family, which has a bifurcated binding pocket for diverse ligands, could serve as excellent biocatalysts in industrial and biotechnological applications. Here, the identification, characterization, and immobilization of a novel YbfF esterase (YbfFHalomonas elongata) from Halomonas elongata DSM 2581 is reported. Biochemical characterization of YbfF was carried out using activity staining, chromatographic analysis, kinetic analysis, activity assay, acetic acid release, and pH-indicator-based hydrolysis. YbfFH.elongata displayed broad substrate specificity, including that for p-nitrophenyl esters, glucose pentaacetate, tert-butyl acetate, and β-lactam-containing compounds, with high efficiency. Based on a homology model of YbfFH.elongata, Trp237 in the substrate-binding pocket, a critical residue for catalytic activity and substrate specificity was identified and characterized. Furthermore, crosslinked enzyme aggregates and nanoflower formation were explored to enhance the chemical stability and recyclability of YbfFH.elongata. The present study is the first report of a YbfF esterase from extremophiles, and explains its protein stability, catalytic activity, substrate specificities and diversities, kinetics, functional residues, amyloid formation, and immobilization.
Collapse
Affiliation(s)
- Wanki Yoo
- Department of Chemistry, Graduate School of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea; Department of Precision Medicine, School of Medicine, SungKyunKwan University, Suwon 16419, Republic of Korea
| | - Booyoung Kim
- Department of Chemistry, Graduate School of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Sangeun Jeon
- Department of Chemistry, Graduate School of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, School of Medicine, SungKyunKwan University, Suwon 16419, Republic of Korea
| | - T Doohun Kim
- Department of Chemistry, Graduate School of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea.
| |
Collapse
|
7
|
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.
Collapse
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:
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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)
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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).
Collapse
|
13
|
MacDonald MJ, Lavis LD, Hilvert D, Gellman SH. Evaluation of the Ser-His Dipeptide, a Putative Catalyst of Amide and Ester Hydrolysis. Org Lett 2016; 18:3518-21. [PMID: 27400366 DOI: 10.1021/acs.orglett.6b01279] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Efficient hydrolysis of amide bonds has long been a reaction of interest for organic chemists. The rate constants of proteases are unmatched by those of any synthetic catalyst. It has been proposed that a dipeptide containing serine and histidine is an effective catalyst of amide hydrolysis, based on an apparent ability to degrade a protein. The capacity of the Ser-His dipeptide to catalyze the hydrolysis of several discrete ester and amide substrates is investigated using previously described conditions. This dipeptide does not catalyze the hydrolysis of amide or unactivated ester groups in any of the substrates under the conditions evaluated.
Collapse
Affiliation(s)
- Melissa J MacDonald
- Department of Chemistry, University of Wisconsin-Madison , Wisconsin 53706, United States
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute , Ashburn, Virginia 20147, United States
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich , 8093 Zürich, Switzerland
| | - Samuel H Gellman
- Department of Chemistry, University of Wisconsin-Madison , Wisconsin 53706, United States
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
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.
Collapse
Affiliation(s)
- Jessica K Lukowski
- Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States
| | | | | | | | | | | | | | | |
Collapse
|