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Karamitros CS, Murray K, Winemiller B, Lamb C, Stone EM, D'Arcy S, Johnson KA, Georgiou G. Leveraging intrinsic flexibility to engineer enhanced enzyme catalytic activity. Proc Natl Acad Sci U S A 2022; 119:e2118979119. [PMID: 35658075 PMCID: PMC9191678 DOI: 10.1073/pnas.2118979119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/01/2022] [Indexed: 11/18/2022] Open
Abstract
Dynamic motions of enzymes occurring on a broad range of timescales play a pivotal role in all steps of the reaction pathway, including substrate binding, catalysis, and product release. However, it is unknown whether structural information related to conformational flexibility can be exploited for the directed evolution of enzymes with higher catalytic activity. Here, we show that mutagenesis of residues exclusively located at flexible regions distal to the active site of Homo sapiens kynureninase (HsKYNase) resulted in the isolation of a variant (BF-HsKYNase) in which the rate of the chemical step toward kynurenine was increased by 45-fold. Mechanistic pre–steady-state kinetic analysis of the wild type and the evolved enzyme shed light on the underlying effects of distal mutations (>10 Å from the active site) on the rate-limiting step of the catalytic cycle. Hydrogen-deuterium exchange coupled to mass spectrometry and molecular dynamics simulations revealed that the amino acid substitutions in BF-HsKYNase allosterically affect the flexibility of the pyridoxal-5′-phosphate (PLP) binding pocket, thereby impacting the rate of chemistry, presumably by altering the conformational ensemble and sampling states more favorable to the catalyzed reaction.
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Affiliation(s)
| | - Kyle Murray
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080
| | - Brent Winemiller
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712
| | - Candice Lamb
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712
| | - Everett M. Stone
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712
- Department of Oncology, Dell Medical School, University of Texas at Austin, Austin, TX 78712
- LiveSTRONG Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX 78712
| | - Sheena D'Arcy
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080
| | - Kenneth A. Johnson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - George Georgiou
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712
- Department of Oncology, Dell Medical School, University of Texas at Austin, Austin, TX 78712
- LiveSTRONG Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX 78712
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712
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PDK2: An Underappreciated Regulator of Liver Metabolism. LIVERS 2021. [DOI: 10.3390/livers1020008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pyruvate metabolism is critical for all mammalian cells. The pyruvate dehydrogenase complex couples the pyruvate formed as the primary product of glycolysis to the formation of acetyl-CoA required as the primary substrate of the citric acid cycle. Dysregulation of this coupling contributes to alterations in metabolic flexibility in obesity, diabetes, cancer, and more. The pyruvate dehydrogenase kinase family of isozymes phosphorylate and inactive the pyruvate dehydrogenase complex in the mitochondria. This function makes them critical mediators of mitochondrial metabolism and drug targets in a number of disease states. The liver expresses multiple PDKs, predominantly PDK1 and PDK2 in the fed state and PDK1, PDK2, and PDK4 in the starved and diabetic states. PDK4 undergoes substantial transcriptional regulation in response to a diverse array of stimuli in most tissues. PDK2 has received less attention than PDK4 potentially due to the dramatic changes in transcriptional gene regulation. However, PDK2 is more responsive than the other PDKs to feedforward and feedback regulation by substrates and products of the pyruvate dehydrogenase complex. Although underappreciated, this makes PDK2 particularly important for the minute-to-minute fine control of the pyruvate dehydrogenase complex and a major contributor to metabolic flexibility. The purpose of this review is to characterize the underappreciated role of PDK2 in liver metabolism. We will focus on known biological actions and physiological roles as well as what roles PDK2 may play in disease states. We will also define current inhibitors and address their potential as therapeutic agents in the future.
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Li Y, Wen L, Qu Y, Lv Y. Metal–Enzyme Hybrid Microspheres Assembled via Mg 2+-Allosteric Effector. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c04721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuan Li
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Liyin Wen
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
- Institute for Medical Device Standard Administration, National Institutes for Food and Drug Control, Beijing 100050, China
| | - Yun Qu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yongqin Lv
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
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Ma X, Qi Y, Lai L. Allosteric sites can be identified based on the residue-residue interaction energy difference. Proteins 2016; 83:1375-84. [PMID: 25185787 DOI: 10.1002/prot.24681] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/20/2014] [Accepted: 08/22/2014] [Indexed: 11/08/2022]
Abstract
Allosteric drugs act at a distance to regulate protein functions. They have several advantages over conventional orthosteric drugs, including diverse regulation types and fewer side effects. However, the rational design of allosteric ligands remains a challenge, especially when it comes to the identification allosteric binding sites. As the binding of allosteric ligands may induce changes in the pattern of residue-residue interactions, we calculated the residue-residue interaction energies within the allosteric site based on the molecular mechanics generalized Born surface area energy decomposition scheme. Using a dataset of 17 allosteric proteins with structural data for both the apo and the ligand-bound state available, we used conformational ensembles generated by molecular dynamics simulations to compute the differences in the residue-residue interaction energies in known allosteric sites from both states. For all the known sites, distinct interaction energy differences (>25%) were observed. We then used CAVITY, a binding site detection program to identify novel putative allosteric sites in the same proteins. This yielded a total of 31 "druggable binding sites," of which 21 exhibited >25% difference in residue interaction energies, and were hence predicted as novel allosteric sites. Three of the predicted allosteric sites were supported by recent experimental studies. All the predicted sites may serve as novel allosteric sites for allosteric ligand design. Our study provides a computational method for identifying novel allosteric sites for allosteric drug design.
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Affiliation(s)
- Xiaomin Ma
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Yifei Qi
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Luhua Lai
- Center for Quantitative Biology, Peking University, Beijing, 100871, China.,BNLMS, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, and Peking-Tsinghua Center for Life Sciences at College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
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Zhang SL, Hu X, Zhang W, Yao H, Tam KY. Development of pyruvate dehydrogenase kinase inhibitors in medicinal chemistry with particular emphasis as anticancer agents. Drug Discov Today 2015; 20:1112-9. [PMID: 25842042 DOI: 10.1016/j.drudis.2015.03.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/10/2015] [Accepted: 03/25/2015] [Indexed: 12/25/2022]
Abstract
Many cancer cells demonstrate a high rate of glucose consumption via glycolysis to provide intermediates for macromolecule biosynthesis. To accomplish this metabolic change, the expression of pyruvate dehydrogenase kinases (PDKs) is rapidly increased in cancer cells. Inhibition of PDKs could promote the function of mitochondria by increasing the oxidative metabolism of pyruvate, resulting in the death of cancer cells. In this review, we provide an overview of the structural information available for PDKs and their connections to known therapeutic effects. We then describe the development of small molecule PDK inhibitors in medicinal chemistry with particular emphasis as anticancer agents. Finally, directions for further development of PDK inhibitors as potential anticancer agents are discussed.
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Affiliation(s)
- Shao-Lin Zhang
- Drug Development Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Xiaohui Hu
- Drug Development Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Wen Zhang
- Drug Development Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Huankai Yao
- Drug Development Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Kin Yip Tam
- Drug Development Core, Faculty of Health Sciences, University of Macau, Macau, China.
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Tao R, Xiong X, Harris RA, White MF, Dong XC. Genetic inactivation of pyruvate dehydrogenase kinases improves hepatic insulin resistance induced diabetes. PLoS One 2013; 8:e71997. [PMID: 23940800 PMCID: PMC3733847 DOI: 10.1371/journal.pone.0071997] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 07/11/2013] [Indexed: 12/12/2022] Open
Abstract
Pyruvate dehydrogenase kinases (PDK1-4) play a critical role in the inhibition of the mitochondrial pyruvate dehydrogenase complex especially when blood glucose levels are low and pyruvate can be conserved for gluconeogenesis. Under diabetic conditions, the Pdk genes, particularly Pdk4, are often induced, and the elevation of the Pdk4 gene expression has been implicated in the increased gluconeogenesis in the liver and the decreased glucose utilization in the peripheral tissues. However, there is no direct evidence yet to show to what extent that the dysregulation of hepatic Pdk genes attributes to hyperglycemia and insulin resistance in vivo. To address this question, we crossed Pdk2 or Pdk4 null mice with a diabetic model that is deficient in hepatic insulin receptor substrates 1 and 2 (Irs1/2). Metabolic analyses reveal that deletion of the Pdk4 gene had better improvement in hyperglycemia and glucose tolerance than knockout of the Pdk2 gene whereas the Pdk2 gene deletion showed better insulin tolerance as compared to the Pdk4 gene inactivation on the Irs1/2 knockout genetic background. To examine the specific hepatic effects of Pdks on diabetes, we also knocked down the Pdk2 or Pdk4 gene using specific shRNAs. The data also indicate that the Pdk4 gene knockdown led to better glucose tolerance than the Pdk2 gene knockdown. In conclusion, our data suggest that hepatic Pdk4 may be critically involved in the pathogenesis of diabetes.
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Affiliation(s)
- Rongya Tao
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Xiwen Xiong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Robert A. Harris
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Richard Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, United States of America
| | - Morris F. White
- Division of Endocrinology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xiaocheng C. Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Walsh JM, Parasuram R, Rajput PR, Rozners E, Ondrechen MJ, Beuning PJ. Effects of non-catalytic, distal amino acid residues on activity of E. coli DinB (DNA polymerase IV). ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:766-776. [PMID: 23034734 DOI: 10.1002/em.21730] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/08/2012] [Accepted: 08/06/2012] [Indexed: 06/01/2023]
Abstract
DinB is one of two Y family polymerases in E. coli and is involved in copying damaged DNA. DinB is specialized to bypass deoxyguanosine adducts that occur at the N(2) position, with its cognate lesion being the furfuryl adduct. Active site residues have been identified that make contact with the substrate and carry out deoxynucleotide triphosphate (dNTP) addition to the growing DNA strand. In DNA polymerases, these include negatively charged aspartate and glutamate residues (D8, D103, and E104 in E. coli DNA polymerase IV DinB). These residues position the essential magnesium ions correctly to facilitate nucleophilic attack by the primer hydroxyl group on the α-phosphate group of the incoming dNTP. To study the contribution of DinB residues to lesion bypass, the computational methods THEMATICS and POOL were employed. These methods correctly predict the known active site residues, as well as other residues known to be important for activity. In addition, these methods predict other residues involved in substrate binding as well as more remote residues. DinB variants with mutations at the predicted positions were constructed and assayed for bypass of the N(2) -furfuryl-dG lesion. We find a wide range of effects of predicted residues, including some mutations that abolish damage bypass. Moreover, most of the DinB variants constructed are unable to carry out the extension step of lesion bypass. The use of computational prediction methods represents another tool that will lead to a more complete understanding of translesion DNA synthesis.
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Affiliation(s)
- Jason M Walsh
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
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Jeoung NH, Rahimi Y, Wu P, Lee WNP, Harris RA. Fasting induces ketoacidosis and hypothermia in PDHK2/PDHK4-double-knockout mice. Biochem J 2012; 443:829-39. [PMID: 22360721 PMCID: PMC4323161 DOI: 10.1042/bj20112197] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The importance of PDHK (pyruvate dehydrogenase kinase) 2 and 4 in regulation of the PDH complex (pyruvate dehydrogenase complex) was assessed in single- and double-knockout mice. PDHK2 deficiency caused higher PDH complex activity and lower blood glucose levels in the fed, but not the fasted, state. PDHK4 deficiency caused similar effects, but only after fasting. Double deficiency intensified these effects in both the fed and fasted states. PDHK2 deficiency had no effect on glucose tolerance, PDHK4 deficiency produced only a modest effect, but double deficiency caused a marked improvement and also induced lower insulin levels and increased insulin sensitivity. In spite of these beneficial effects, the double-knockout mice were more sensitive than wild-type and single-knockout mice to long-term fasting, succumbing to hypoglycaemia, ketoacidosis and hypothermia. Stable isotope flux analysis indicated that hypoglycaemia was due to a reduced rate of gluconeogenesis and that slightly more glucose was converted into ketone bodies in the double-knockout mice. The findings establish that PDHK2 is more important in the fed state, PDHK4 is more important in the fasted state, and survival during long-term fasting depends upon regulation of the PDH complex by both PDHK2 and PDHK4.
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Affiliation(s)
- Nam Ho Jeoung
- Richard Roudebush Veterans Affairs Medical Center, 1481 West Tenth Street, Indianapolis, IN 46202, U.S.A
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - Yasmeen Rahimi
- Richard Roudebush Veterans Affairs Medical Center, 1481 West Tenth Street, Indianapolis, IN 46202, U.S.A
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - Pengfei Wu
- Richard Roudebush Veterans Affairs Medical Center, 1481 West Tenth Street, Indianapolis, IN 46202, U.S.A
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - W. N. Paul Lee
- Department of Pediatrics, Harbor-UCLA Medical Center, 1000 West Carson Street, Torrance, CA 90502, U.S.A
| | - Robert A. Harris
- Richard Roudebush Veterans Affairs Medical Center, 1481 West Tenth Street, Indianapolis, IN 46202, U.S.A
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
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Lee J, Goodey NM. Catalytic contributions from remote regions of enzyme structure. Chem Rev 2011; 111:7595-624. [PMID: 21923192 DOI: 10.1021/cr100042n] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jeeyeon Lee
- Department of Chemistry, 413 Wartik Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Li J, Kato M, Chuang DT. Pivotal role of the C-terminal DW-motif in mediating inhibition of pyruvate dehydrogenase kinase 2 by dichloroacetate. J Biol Chem 2009; 284:34458-67. [PMID: 19833728 DOI: 10.1074/jbc.m109.065557] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial pyruvate dehydrogenase complex (PDC) is down-regulated by phosphorylation catalyzed by pyruvate dehydrogenase kinase (PDK) isoforms 1-4. Overexpression of PDK isoforms and therefore reduced PDC activity prevails in cancer and diabetes. In the present study, we investigated the role of the invariant C-terminal DW-motif in inhibition of human PDK2 by dichloroacetate (DCA). Substitutions were made in the DW-motif (Asp-382 and Trp-383) and its interacting residues (Tyr-145 and Arg-149) in the other subunit of PDK2 homodimer. Single and double mutants show 20-60% residual activities that are not stimulated by the PDC core. The R149A and Y145F/R149A mutants show drastic increases in apparent IC(50) values for DCA, whereas binding affinities for DCA are comparable with wild-type PDK2. Both R149A and Y145F variants exhibit increased similar affinities for ADP and ATP, mimicking the effects of DCA. The R149A and the DW-motif mutations (D382A/W383A) forestall binding of the lipoyl domain of PDC to these mutants, analogous to wild-type PDK2 in the presence of DCA and ADP. In contrast, the binding of a dihydrolipoamide mimetic AZD7545 is largely unaffected in these PDK2 variants. Our results illuminate the pivotal role of the DW-motif in mediating communications between the DCA-, the nucleotide-, and the lipoyl domain-binding sites. This signaling network locks PDK2 in the inactive closed conformation, which is in equilibrium with the active open conformation without DCA and ADP. These results implicate the DW-motif anchoring site as a drug target for the inhibition of aberrant PDK activity in cancer and diabetes.
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Affiliation(s)
- Jun Li
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, USA
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