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Sánchez-Arroyo A, Plaza-Vinuesa L, de Las Rivas B, Mancheño JM, Muñoz R. Structural and functional analysis of the key enzyme responsible for the degradation of ochratoxin A in the Alcaligenes genus. Int J Biol Macromol 2024; 267:131342. [PMID: 38574921 DOI: 10.1016/j.ijbiomac.2024.131342] [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: 12/08/2023] [Revised: 03/01/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
The potential to degrade ochratoxin A (OTA), a highly poisonous mycotoxin, was investigated in cultures from Alcaligenes-type strains. Genome sequence analyses from different Alcaligenes species have permitted us to demonstrate a direct, causal link between the gene coding a known N-acyl-L-amino acid amidohydrolase from A. faecalis (AfOTH) and the OTA-degrading activity of this bacterium. In agreement with this finding, we found the gene coding AfOTH in two additional species included in the Alcaligenes genus, namely, A. pakistanensis, and A. aquatilis, which also degraded OTA. Notably, A. faecalis subsp. faecalis DSM 30030T was able to transform OTα, the product of OTA hydrolysis. AfOTH from A. faecalis subsp. phenolicus DSM 16503T was recombinantly over-produced and enzymatically characterized. AfOTH is a Zn2+-containing metalloenzyme that possesses structural features and conserved residues identified in the M20D family of enzymes. AfOTH is a tetramer in solution that shows both aminoacylase and carboxypeptidase activities. Using diverse potential substrates, namely, N-acetyl-L-amino acids and carbobenzyloxy-L-amino acids, a marked preference towards C-terminal Phe and Tyr residues could be deduced. The structural basis for this specificity has been determined by in silico molecular docking analyses. The amidase activity of AfOTH on C-terminal Phe residues structurally supports its OTA and OTB degradation activity.
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Affiliation(s)
- Ana Sánchez-Arroyo
- Bacterial Biotechnology Laboratory, Institute of Food Science, Technology and Nutrition (ICTAN), CSIC, José Antonio Novais 6, 28040 Madrid, Spain
| | - Laura Plaza-Vinuesa
- Bacterial Biotechnology Laboratory, Institute of Food Science, Technology and Nutrition (ICTAN), CSIC, José Antonio Novais 6, 28040 Madrid, Spain
| | - Blanca de Las Rivas
- Bacterial Biotechnology Laboratory, Institute of Food Science, Technology and Nutrition (ICTAN), CSIC, José Antonio Novais 6, 28040 Madrid, Spain
| | - José Miguel Mancheño
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry Blas Cabrera (IQF), CSIC, Serrano 119, 28006 Madrid, Spain.
| | - Rosario Muñoz
- Bacterial Biotechnology Laboratory, Institute of Food Science, Technology and Nutrition (ICTAN), CSIC, José Antonio Novais 6, 28040 Madrid, Spain.
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2
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Mine S, Nakabayashi M, Ishikawa K. Crystal structure of thermostable acetaldehyde dehydrogenase from the hyperthermophilic archaeon Sulfolobus tokodaii. Acta Crystallogr F Struct Biol Commun 2023; 79:159-165. [PMID: 37227376 PMCID: PMC10231261 DOI: 10.1107/s2053230x23004430] [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: 02/15/2023] [Accepted: 05/22/2023] [Indexed: 05/26/2023] Open
Abstract
Aldehyde dehydrogenase (ALDH) is widely distributed in nature and its characteristics have been examined. ALDH plays an important role in aldehyde detoxification. Sources of aldehydes include incomplete combustion and emissions from paints, linoleum and varnishes in the living environment. Acetaldehyde is also considered to be carcinogenic and toxic. Thermostable ALDH from the hyperthermophilic archaeon Sulfolobus tokodaii exhibits high activity towards acetaldehyde and has potential applications as a biosensor for acetaldehyde. Thermostable ALDH displays a unique and wide adaptability. Therefore, its crystal structure can provide new insights into the catalytic mechanism and potential applications of ALDHs. However, a crystal structure of a thermostable ALDH exhibiting high activity towards acetaldehyde has not been reported to date. In this study, crystals of recombinant thermostable ALDH from S. tokodaii were prepared and the crystal structure of its holo form was determined. A crystal of the enzyme was prepared and its structure in complex with NADP was determined at a resolution of 2.2 Å. This structural analysis may facilitate further studies on catalytic mechanisms and applications.
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Affiliation(s)
- Shohei Mine
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Makoto Nakabayashi
- Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka 584-8540, Japan
| | - Kazuhiko Ishikawa
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
- Rare Sugar and Enzyme Research, Dep. I, R&D, Matsutani Chemical Industry Co. Ltd, 5-3 Kitaitami, Itami City, Hyogo 664-8508, Japan
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3
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Hayashi J, Ichiki Y, Kanda A, Takagi K, Wakayama M. Identification, characterization, and cloning of a novel aminoacylase, L-pipecolic acid acylase from Pseudomonas species. J GEN APPL MICROBIOL 2021; 67:186-194. [PMID: 34176819 DOI: 10.2323/jgam.2020.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
L-Pipecolic acid is utilized as a vital component of specific chemical compounds, such as immunosuppressive drugs, anticancer reagents, and anesthetic reagents. We isolated and characterized a novel L-aminoacylase, N-acetyl-L-pipecolic acid-specific aminoacylase (LpipACY), from Pseudomonas sp. AK2. The subunit molecular mass of LpipACY was 45 kDa and was assumed to be a homooctamer in solution. The enzyme exhibited high substrate specificity toward N-acetyl-L-pipecolic acid and a high activity for N-acetyl-L-pipecolic acid and N-acetyl-L-proline. This enzyme was stable at a high temperature (60°C for 10 min) and under an alkaline pH (6.0-11.5). The N-terminal and internal amino acid sequences of the purified enzyme were STTANTLILRNG and IMASGGV, respectively. These sequences are highly consistent with those of uncharacterized proteins from Pseudomonas species, such as amidohydrolase and peptidase. We also cloned and overexpressed the gene coding LpipACY in Escherichia coli. Moreover, the recombinant LpipACY exhibited properties similar to native enzyme. Our results suggest that LpipACY is a potential enzyme for the enzymatic synthesis of L-pipecolic acid. This study provides the first description of the enzymatic characterization of L-pipecolic acid specific amino acid acylase.
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Affiliation(s)
- Junji Hayashi
- Faculty of Bioscience and Bioindustry, Tokushima University
| | - Yoshiaki Ichiki
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University
| | - Akiko Kanda
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University
| | - Kazuyoshi Takagi
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University
| | - Mamoru Wakayama
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University
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4
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Fernandes GC, Sierra EGM, Brear P, Pereira MR, Lemos EGM. From Data Mining of Chitinophaga sp. Genome to Enzyme Discovery of a Hyperthermophilic Metallocarboxypeptidase. Microorganisms 2021; 9:393. [PMID: 33673011 PMCID: PMC7918520 DOI: 10.3390/microorganisms9020393] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 01/24/2023] Open
Abstract
For several centuries, microorganisms and enzymes have been used for many different applications. Although many enzymes with industrial applications have already been reported, different screening technologies, methods and approaches are constantly being developed in order to allow the identification of enzymes with even more interesting applications. In our work, we have performed data mining on the Chitinophaga sp. genome, a gram-negative bacterium isolated from a bacterial consortium of sugarcane bagasse isolated from an ethanol plant. The analysis of 8 Mb allowed the identification of the chtcp gene, previously annotated as putative Cht4039. The corresponding codified enzyme, denominated as ChtCP, showed the HEXXH conserved motif of family M32 from thermostable carboxypeptidases. After expression in E. coli, the recombinant enzyme was characterized biochemically. ChtCP showed the highest activity versus benziloxicarbonil Ala-Trp at pH 7.5, suggesting a preference for hydrophobic substrates. Surprisingly, the highest activity of ChtCP observed was between 55 °C and 75 °C, and 62% activity was still displayed at 100 °C. We observed that Ca2+, Ba2+, Mn2+ and Mg2+ ions had a positive effect on the activity of ChtCP, and an increase of 30 °C in the melting temperature was observed in the presence of Co2+. These features together with the structure of ChtCP at 1.2 Å highlight the relevance of ChtCP for further biotechnological applications.
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Affiliation(s)
- Gabriela Cabral Fernandes
- Department of Technology, São Paulo State University (UNESP), Jaboticabal, São Paulo State 14884-900, Brazil; (G.C.F.); (E.G.M.S.)
- Graduate Program in Agricultural and Livestock Microbiology, São Paulo State University (UNESP), School of Agricultural and Veterinarian Sciences, Jaboticabal, São Paulo State 14884-900, Brazil
| | - Elwi Guillermo Machado Sierra
- Department of Technology, São Paulo State University (UNESP), Jaboticabal, São Paulo State 14884-900, Brazil; (G.C.F.); (E.G.M.S.)
- Laboratorio de Investigación en Microbiología, Facultad de Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla 080002, Colombia
| | - Paul Brear
- Department of Biochemistry, University of Cambridge, Cambridge CB21GA, UK;
| | - Mariana Rangel Pereira
- Department of Biochemistry, University of Cambridge, Cambridge CB21GA, UK;
- CAPES Foundation, Ministry of Education of Brazil, Brasília-DF 70.040-02, Brazil
| | - Eliana G. M. Lemos
- Department of Technology, São Paulo State University (UNESP), Jaboticabal, São Paulo State 14884-900, Brazil; (G.C.F.); (E.G.M.S.)
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5
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Functional annotation of operome from Methanothermobacter thermautotrophicus ΔH: An insight to metabolic gap filling. Int J Biol Macromol 2018; 123:350-362. [PMID: 30445075 DOI: 10.1016/j.ijbiomac.2018.11.100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/10/2018] [Accepted: 11/12/2018] [Indexed: 12/16/2022]
Abstract
Methanothermobacter thermautotrophicus ΔH (MTH) is a potential methanogen known to reduce CO2 with H2 for producing methane biofuel in thermophilic digesters. The genome of this organism contains ~50.5% conserved hypothetical proteins (HPs; operome) whose function is still not determined precisely. Here, we employed a combined bioinformatics approach to annotate a precise function to HPs and categorize them as enzymes, binding proteins, and transport proteins. Results of our study show that 315 (35.6%) HPs have exhibited well-defined functions contributing imperative roles in diverse cellular metabolism. Some of them are responsible for stress-response mechanisms and cell cycle, membrane transport, and regulatory processes. The genome-neighborhood analysis found five important gene clusters (dsr, ehb, kaiC, cmr, and gas) involving in the energetic metabolism and defense systems. MTH operome contains 223 enzymes with 15 metabolic subsystems, 15 cell cycle proteins, 17 transcriptional regulators and 33 binding proteins. Functional annotation of its operome is thus more fundamental to a profound understanding of the molecular and cellular machinery at systems-level.
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6
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Tomita T. Structure, function, and regulation of enzymes involved in amino acid metabolism of bacteria and archaea. Biosci Biotechnol Biochem 2017; 81:2050-2061. [PMID: 28840778 DOI: 10.1080/09168451.2017.1365593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Amino acids are essential components in all organisms because they are building blocks of proteins. They are also produced industrially and used for various purposes. For example, L-glutamate is used as the component of "umami" taste and lysine has been used as livestock feed. Recently, many kinds of amino acids have attracted attention as biological regulators and are used for a healthy life. Thus, to clarify the mechanism of how amino acids are biosynthesized and how they work as biological regulators will lead to further effective utilization of them. Here, I review the leucine-induced-allosteric activation of glutamate dehydrogenase (GDH) from Thermus thermophilus and the relationship with the allosteric regulation of GDH from mammals. Next, I describe structural insights into the efficient production of L-glutamate by GDH from an excellent L-glutamate producer, Corynebacterium glutamicum. Finally, I review the structural biology of lysine biosynthesis of thermophilic bacterium and archaea.
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Affiliation(s)
- Takeo Tomita
- a Department of Biotechnology, Biotechnology Research Center , The University of Tokyo , Tokyo , Japan
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7
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Takahashi K, Tomita T, Kuzuyama T, Nishiyama M. Determinants of dual substrate specificity revealed by the crystal structure of homoisocitrate dehydrogenase from Thermus thermophilus in complex with homoisocitrate·Mg(2+)·NADH. Biochem Biophys Res Commun 2016; 478:1688-93. [PMID: 27601325 DOI: 10.1016/j.bbrc.2016.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 11/17/2022]
Abstract
HICDH (Homoisocitrate dehydrogenase) is a member of the β-decarboxylating dehydrogenase family that catalyzes the conversion of homoisocitrate to α-ketoadipate using NAD(+) as a coenzyme, which is the fourth reaction involved in lysine biosynthesis through the α-aminoadipate pathway. Although typical HICDHs from fungi and yeast exhibit strict substrate specificities toward homoisocitrate (HIC), HICDH from a thermophilic bacterium Thermus thermophilus (TtHICDH) catalyzes the reactions using both HIC and isocitrate (IC) as substrates at similar efficiencies. We herein determined the crystal structure of the quaternary complex of TtHICDH with HIC, NADH, and Mg(2+) ion at a resolution of 2.5 Å. The structure revealed that the distal carboxyl group of HIC was recognized by the side chains of Ser72 and Arg85 from one subunit, and Asn173 from another subunit of a dimer unit. Model structures were constructed for TtHICDH in complex with IC and also for HICDH from Saccharomyces cerevisiae (ScHICDH) in complex with HIC. TtHICDH recognized the distal carboxyl group of IC by Arg85 in the model. In ScHICDH, the distal carboxyl group of HIC was recognized by the side chains of Ser98 and Ser108 from one subunit and Asn208 from another subunit of a dimer unit. By contrast, in ScHICDH, which lacks an Arg residue at the position corresponding to Arg85 in TtHICDH, these residues may not interact with the distal carboxyl group of shorter IC. These results provide a molecular basis for the differences in substrate specificities between TtHICDH and ScHICDH.
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Affiliation(s)
- Kento Takahashi
- Biotechnology Research Center, The University of Tokyo, Japan
| | - Takeo Tomita
- Biotechnology Research Center, The University of Tokyo, Japan
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8
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Characterization of two β-decarboxylating dehydrogenases from Sulfolobus acidocaldarius. Extremophiles 2016; 20:843-853. [DOI: 10.1007/s00792-016-0872-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 08/25/2016] [Indexed: 11/26/2022]
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9
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Jamdar SN, Are VN, Navamani M, Kumar S, Nagar V, Makde RD. The members of M20D peptidase subfamily from Burkholderia cepacia, Deinococcus radiodurans and Staphylococcus aureus (HmrA) are carboxydipeptidases, primarily specific for Met-X dipeptides. Arch Biochem Biophys 2015; 587:18-30. [DOI: 10.1016/j.abb.2015.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/20/2015] [Accepted: 10/05/2015] [Indexed: 11/28/2022]
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10
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Jia B, Cheong GW, Zhang S. Multifunctional enzymes in archaea: promiscuity and moonlight. Extremophiles 2013; 17:193-203. [PMID: 23283522 DOI: 10.1007/s00792-012-0509-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
Abstract
Enzymes from many archaea colonizing extreme environments are of great interest because of their potential for various biotechnological processes and scientific value of evolution. Many enzymes from archaea have been reported to catalyze promiscuous reactions or moonlight in different functions. Here, we summarize known archaeal enzymes of both groups that include different kinds of proteins. Knowledge of their biochemical properties and three-dimensional structures has proved invaluable in understanding mechanism, application, and evolutionary implications of this manifestation. In addition, the review also summarizes the methods to unravel the extra function which almost was discovered serendipitously. The study of these amazing enzymes will provide clues to optimize protein engineering applications and how enzymes might have evolved on Earth.
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Affiliation(s)
- Baolei Jia
- College of Plant Sciences, Jilin University, Changchun, China.
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11
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Tsirulnikov K, Abuladze N, Vahi R, Hasnain H, Phillips M, Ryan CM, Atanasov I, Faull KF, Kurtz I, Pushkin A. Aminoacylase 3 binds to and cleaves the N-terminus of the hepatitis C virus core protein. FEBS Lett 2012; 586:3799-804. [PMID: 23010594 DOI: 10.1016/j.febslet.2012.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/30/2012] [Accepted: 09/06/2012] [Indexed: 01/13/2023]
Abstract
Aminoacylase 3 (AA3) mediates deacetylation of N-acetyl aromatic amino acids and mercapturic acids. Deacetylation of mercapturic acids of exo- and endobiotics are likely involved in their toxicity. AA3 is predominantly expressed in kidney, and to a lesser extent in liver, brain, and blood. AA3 has been recently reported to interact with the hepatitis C virus core protein (HCVCP) in the yeast two-hybrid system. Here we demonstrate that AA3 directly binds to HCVCP (K(d) ~10 μM) that may by implicated in HCV pathogenesis. AA3 also revealed a weak endopeptidase activity towards the N-terminus of HCVCP.
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Affiliation(s)
- Kirill Tsirulnikov
- Division of Nephrology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, CA 90095, USA.
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12
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Directed evolution of a thermostable l-aminoacylase biocatalyst. J Biotechnol 2011; 155:396-405. [DOI: 10.1016/j.jbiotec.2011.07.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 07/18/2011] [Accepted: 07/25/2011] [Indexed: 11/21/2022]
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13
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Barzantny H, Brune I, Tauch A. Molecular basis of human body odour formation: insights deduced from corynebacterial genome sequences. Int J Cosmet Sci 2011; 34:2-11. [PMID: 21790661 DOI: 10.1111/j.1468-2494.2011.00669.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
During the past few decades, there has been an increased interest in the essential role of commensal skin bacteria in human body odour formation. It is now generally accepted that skin bacteria cause body odour by biotransformation of sweat components secreted in the human axillae. Especially, aerobic corynebacteria have been shown to contribute strongly to axillary malodour, whereas other human skin residents seem to have little influence. Analysis of odoriferous sweat components has shown that the major odour-causing substances in human sweat include steroid derivatives, short volatile branched-chain fatty acids and sulphanylalkanols. In this mini-review, we describe the molecular basis of the four most extensively studied routes of human body odour formation, while focusing on the underlying enzymatic processes. Considering the previously reported role of β-oxidation in odour formation, we analysed the genetic repertoire of eight Corynebacterium species concerning fatty acid metabolism. We particularly focused on the metabolic abilities of the lipophilic axillary isolate Corynebacterium jeikeium K411.
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Affiliation(s)
- H Barzantny
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany.
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14
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Tayyab M, Rashid N, Angkawidjaja C, Kanaya S, Akhtar M. Highly active metallocarboxypeptidase from newly isolated Geobacillus strain SBS-4S: cloning and characterization. J Biosci Bioeng 2010; 111:259-65. [PMID: 21126910 DOI: 10.1016/j.jbiosc.2010.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 11/01/2010] [Accepted: 11/04/2010] [Indexed: 11/29/2022]
Abstract
The carboxypeptidase gene from Geobacillus SBS-4S was cloned and sequenced. The sequence analysis displayed the gene consists of an open reading frame of 1503 nucleotides encoding a protein of 500 amino acids (CBP(SBS)). The amino acid sequence comparison revealed that CBP(SBS) exhibited a highest homology of 41.6% (identity) with carboxypeptidase Taq from Thermus aquaticus among the characterized proteases. CBP(SBS) contained an active site motif (265)HEXXH(269) which is conserved in family-M32 of carboxypeptidases. The gene was expressed with His-Tag utilizing Escherichia coli expression system and purified to apparent homogeneity. The purified CBP(SBS) showed highest activity at pH 7.5 and 70°C. The enzyme activity was metal ion dependent. Among metal ions highest activity was found in the presence of Co(2+). Thermostability studies of CBP(SBS) by circular dichroism spectroscopy demonstrated the melting temperature of the protein around 77°C. The enzyme exhibited K(m) and V(max) values of 14 mM and 10526 μmol min(-1) mg(-1) when carbobenzoxy-alanine-arginine was used as substrate. k(cat) and k(cat)/K(m) valves were 10175 s(-1) and 726 mM(-1) s(-1). To our knowledge this is the highest ever reported enzyme activity of a metallocarboxypeptidase and the first characterization of a metallocarboxypeptidase from genus Geobacillus.
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Affiliation(s)
- Muhammad Tayyab
- School of Biological Sciences, University of Punjab, Quaid-e-Azam Campus, Lahore 54590, Pakistan
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15
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Lindner HA, Alary A, Wilke M, Sulea T. Probing the Acyl-Binding Pocket of Aminoacylase-1. Biochemistry 2008; 47:4266-75. [DOI: 10.1021/bi702156h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Holger A. Lindner
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2
| | - Alain Alary
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2
| | - Marsha Wilke
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2
| | - Traian Sulea
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2
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16
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Tanimoto K, Higashi N, Nishioka M, Ishikawa K, Taya M. Characterization of thermostable aminoacylase from hyperthermophilic archaeon Pyrococcus horikoshii. FEBS J 2008; 275:1140-9. [DOI: 10.1111/j.1742-4658.2008.06274.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Babor M, Gerzon S, Raveh B, Sobolev V, Edelman M. Prediction of transition metal-binding sites from apo protein structures. Proteins 2008; 70:208-17. [PMID: 17657805 DOI: 10.1002/prot.21587] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Metal ions are crucial for protein function. They participate in enzyme catalysis, play regulatory roles, and help maintain protein structure. Current tools for predicting metal-protein interactions are based on proteins crystallized with their metal ions present (holo forms). However, a majority of resolved structures are free of metal ions (apo forms). Moreover, metal binding is a dynamic process, often involving conformational rearrangement of the binding pocket. Thus, effective predictions need to be based on the structure of the apo state. Here, we report an approach that identifies transition metal-binding sites in apo forms with a resulting selectivity >95%. Applying the approach to apo forms in the Protein Data Bank and structural genomics initiative identifies a large number of previously unknown, putative metal-binding sites, and their amino acid residues, in some cases providing a first clue to the function of the protein.
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Affiliation(s)
- Mariana Babor
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, Israel
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18
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Le Coq J, An HJ, Lebrilla C, Viola RE. Characterization of human aspartoacylase: the brain enzyme responsible for Canavan disease. Biochemistry 2006; 45:5878-84. [PMID: 16669630 PMCID: PMC2566822 DOI: 10.1021/bi052608w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aspartoacylase catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate and is the only brain enzyme that has been shown to effectively metabolize NAA. Although the exact role of this enzymatic reaction has not yet been completely elucidated, the metabolism of NAA appears to be necessary in the formation of myelin lipids, and defects in this enzyme lead to Canavan disease, a fatal neurological disorder. The low catalytic activity and inherent instability observed with the Escherichia coli-expressed form of aspartoacylase suggested the need for a suitable eukaryotic expression system that would be capable of producing a fully functional, mature enzyme. Human aspartoacylase has now been successfully expressed in Pichia pastoris. While the expression yields are lower than in E. coli, the purified enzyme is significantly more stable. This enzyme form has the same substrate specificity but is 150-fold more active than the E. coli-expressed enzyme. The molecular weight of the purified enzyme, measured by mass spectrometry, is higher than predicted, suggesting the presence of some post-translational modifications. Deglycosylation of aspartoacylase or mutation at the glycosylation site causes decreased enzyme stability and diminished catalytic activity. A carbohydrate component has been removed and characterized by mass spectrometry. In addition to this carbohydrate moiety, the enzyme has also been shown to contain one zinc atom per subunit. Chelation studies to remove the zinc result in a reversible loss of catalytic activity, thus establishing aspartoacylase as a zinc metalloenzyme.
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Affiliation(s)
| | | | | | - Ronald E. Viola
- To whom correspondence should be addressed: E-Mail: ., Phone: 419-530-1582., Fax: 419-530-1583
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Liljeblad A, Kanerva LT. Biocatalysis as a profound tool in the preparation of highly enantiopure β-amino acids. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.03.109] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Miyazaki K. Bifunctional isocitrate-homoisocitrate dehydrogenase: a missing link in the evolution of beta-decarboxylating dehydrogenase. Biochem Biophys Res Commun 2005; 331:341-6. [PMID: 15845397 DOI: 10.1016/j.bbrc.2005.03.169] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Indexed: 10/25/2022]
Abstract
Beta-decarboxylating dehydrogenases comprise 3-isopropylmalate dehydrogenase, isocitrate dehydrogenase, and homoisocitrate dehydrogenase. They share a high degree of amino acid sequence identity and occupy equivalent positions in the amino acid biosynthetic pathways for leucine, glutamate, and lysine, respectively. Therefore, not only the enzymes but also the whole pathways should have evolved from a common ancestral pathway. In Pyrococcus horikoshii, only one pathway of the three has been identified in the genomic sequence, and PH1722 is the sole beta-decarboxylating dehydrogenase gene. The organism does not require leucine, glutamate, or lysine for growth; the single pathway might play multiple (i.e., ancestral) roles in amino acid biosynthesis. The PH1722 gene was cloned and expressed in Escherichia coli and the substrate specificity of the recombinant enzyme was investigated. It exhibited activities on isocitrate and homoisocitrate at near equal efficiency, but not on 3-isopropylmalate. PH1722 is thus a novel, bifunctional beta-decarboxylating dehydrogenase, which likely plays a dual role in glutamate and lysine biosynthesis in vivo.
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Affiliation(s)
- Kentaro Miyazaki
- Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan.
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21
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Herga S, Brutus A, Vitale RM, Miche H, Perrier J, Puigserver A, Scaloni A, Giardina T. Site-directed mutagenesis and molecular modelling studies show the role of Asp82 and cysteines in rat acylase 1, a member of the M20 family. Biochem Biophys Res Commun 2005; 330:540-6. [PMID: 15796916 DOI: 10.1016/j.bbrc.2005.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Indexed: 11/19/2022]
Abstract
Acylase 1 from rat kidney catalyzes the hydrolysis of acyl-amino acids. Sequence alignment has shown that this enzyme belongs to the metalloprotein family M20. Site-directed mutagenesis experiments led to the identification of one functionally important amino acid residue located near one of the zinc coordinating residues, which play a critical role in the enzymatic activity. The D82N- and D82E-substituted forms showed no significant activity and very low activity, respectively, along with a loss of zinc coordination. Molecular modelling investigations indicated a putative role of D82 in ensuring a proper protonation of catalytic histidine. In addition, none of the five cysteine residues present in the rat kidney acylase 1 sequence seemed involved in the catalytic process: the loss of activity induced by the C294A substitution was probably due to a conformational change in the 3D structure.
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Affiliation(s)
- Sameh Herga
- Institut Méditerranéen de Recherche en Nutrition, Laboratoire de Biochimie et Biologie de la Nutrition, UMR Université Paul Cézanne Aix Marseille III-INRA 1111, service 342, Faculté des Sciences et Techniques Saint-Jérôme, 13397 Marseille Cedex 20, France
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22
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Hernick M, Fierke CA. Zinc hydrolases: the mechanisms of zinc-dependent deacetylases. Arch Biochem Biophys 2005; 433:71-84. [PMID: 15581567 DOI: 10.1016/j.abb.2004.08.006] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 08/04/2004] [Indexed: 11/17/2022]
Abstract
A class of metalloenzymes, known as zinc hydrolases, catalyze a variety of hydrolytic reactions on many different substrates in important metabolic pathways. Deacetylation is an example of one of the types of reactions catalyzed by zinc hydrolases. The biological importance of the reactions catalyzed by many zinc hydrolases, including zinc-dependent deacetylases, has made these enzymes pharmaceutical targets for the development of inhibitors and, therefore, a clear understanding of the mechanisms of these enzymes is warranted. This review focuses on the current understanding of the mechanisms catalyzed by various zinc-dependent deacetylases and, in particular, the reaction mechanism catalyzed by the enzyme UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase, also known as LpxC. In general, the zinc-water functions as the nucleophile with zinc stabilization of the tetrahedral intermediate and general-acid-base catalysis (GABC) provided by enzyme residue(s). Two types of GABC mechanisms have been identified, one that uses a single bifunctional GABC and another that uses a GABC pair.
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Affiliation(s)
- Marcy Hernick
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
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23
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Yasutake Y, Yao M, Sakai N, Kirita T, Tanaka I. Crystal structure of the Pyrococcus horikoshii isopropylmalate isomerase small subunit provides insight into the dual substrate specificity of the enzyme. J Mol Biol 2004; 344:325-33. [PMID: 15522288 DOI: 10.1016/j.jmb.2004.09.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Revised: 09/14/2004] [Accepted: 09/15/2004] [Indexed: 10/26/2022]
Abstract
Recent studies have implied that the isopropylmalate isomerase small subunit of the hyperthermophilic archaea Pyrococcus horikoshii (PhIPMI-s) functions as isopropylmalate isomerase in the leucine biosynthesis pathway, and as homoaconitase (HACN) in the lysine biosynthesis pathway via alpha-aminoadipic acid. PhIPMI is thus considered a key to understanding the fundamental metabolism of the earliest organisms. We describe for the first time the crystal structure of PhIPMI-s, which displays dual substrate specificity. The crystal structure unexpectedly shows that four molecules create an interlocked assembly with intermolecular disulfide linkages having a skewed 222 point-group symmetry. Although the overall fold of the PhIPMI-s monomer is related closely to domain 4 of the aconitase (ACN), one alpha-helix in the ACN structure is replaced by a short loop with relatively high temperature factor values. Because this region is essential for discriminating the structurally similar substrate based on interactions with its diversified gamma-moiety, the loop structure in the PhIPMI-s must be dependent on the presence of a substrate. The flexibility of the loop region might be a structural basis for recognizing both hydrophobic and hydrophilic gamma-moieties of two distinct substrates, isopropylmalate and homocitrate.
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Affiliation(s)
- Yoshiaki Yasutake
- Division of Biological Sciences, Graduate School of Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
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24
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Lombo T, Takaya N, Miyazaki J, Gotoh K, Nishiyama M, Kosuge T, Nakamura A, Hoshino T. Functional analysis of the small subunit of the putative homoaconitase fromPyrococcus horikoshiiin theThermuslysine biosynthetic pathway. FEMS Microbiol Lett 2004. [DOI: 10.1111/j.1574-6968.2004.tb09498.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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25
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Durand A, Giardina T, Villard C, Roussel A, Puigserver A, Perrier J. Rat kidney acylase I: further characterisation and mutation studies on the involvement of Glu 147 in the catalytic process. Biochimie 2003; 85:953-62. [PMID: 14644550 DOI: 10.1016/j.biochi.2003.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Rat kidney acylase I was characterised by performing site-directed mutagenesis and enzymatic analysis in the presence of various chemical inhibitors. Site-directed mutagenesis on E147 and overexpression of the protein in a bacterial system, revealed the importance of this residue in enzymatic activity, it corresponds to the putative catalytic E175 in carboxypeptidase G2 from Pseudomonas aeruginosa. The reactivity of histidine and cysteine residues of acylase I with diethylpyrocarbonate (DEPC) and mercuric chloride, respectively, showed that these two amino acids are required for the enzyme to be fully active. Interestingly, the effects of mercuric chloride on rat kidney acylase I were not as great as those on the porcine enzyme, in agreement with previously observed differences between the two enzymes. Moreover, N-[3-(2-furyl)-acryloyl-L-methionine] (FA-Met) a synthetic substrate of the porcine acylase I was found to be an inhibitor of the rat kidney enzyme. These results strongly suggest the existence of differences between the active site of rat and porcine kidney acylases I. Lastly, the rat kidney enzyme was as sensitive as its porcine counterpart to two metal chelating agents, 1,10-phenanthroline and ethylenediamine tetraacetate (EDTA).
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Affiliation(s)
- Anne Durand
- Faculté des Sciences et Techniques Saint-Jérôme, Institut Méditerranéen de Recherche en Nutrition, Service 342, Umr Université Aix-Marseille III-INRA 1111, avenue Escadrille-Normandie-Niemen, 13397 Marseille cedex 20, France
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26
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Occhipinti E, Martelli PL, Spinozzi F, Corsi F, Formantici C, Molteni L, Amenitsch H, Mariani P, Tortora P, Casadio R. 3D structure of Sulfolobus solfataricus carboxypeptidase developed by molecular modeling is confirmed by site-directed mutagenesis and small angle X-ray scattering. Biophys J 2003; 85:1165-75. [PMID: 12885660 PMCID: PMC1303234 DOI: 10.1016/s0006-3495(03)74552-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Sulfolobus solfataricus carboxypeptidase (CPSso) is a thermostable zinc-metalloenzyme with a M(r) of 43,000. Taking into account the experimentally determined zinc content of one ion per subunit, we developed two alternative 3D models, starting from the available structures of Thermoactinomyces vulgaris carboxypeptidase (Model A) and Pseudomonas carboxypeptidase G2 (Model B). The former enzyme is monomeric and has one metal ion in the active site, while the latter is dimeric and has two bound zinc ions. The two models were computed by exploiting the structural alignment of the one zinc- with the two zinc-containing active sites of the two templates, and with a threading procedure. Both computed structures resembled the respective template, with only one bound zinc with tetrahedric coordination in the active site. With these models, two different quaternary structures can be modeled: one using Model A with a hexameric symmetry, the other from Model B with a tetrameric symmetry. Mutagenesis experiments directed toward the residues putatively involved in metal chelation in either of the models disproved Model A and supported Model B, in which the metal-binding site comprises His(108), Asp(109), and His(168). We also identified Glu(142) as the acidic residue interacting with the water molecule occupying the fourth chelation site. Furthermore, the overall fold and the oligomeric structure of the molecule was validated by small angle x-ray scattering (SAXS). An ab initio original approach was used to reconstruct the shape of the CPSso in solution from the experimental curves. The results clearly support a tetrameric structure. The Monte Carlo method was then used to compare the crystallographic coordinates of the possible quaternary structures for CPSso with the SAXS profiles. The fitting procedure showed that only the model built using the Pseudomonas carboxypeptidase G2 structure as a template fitted the experimental data.
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Affiliation(s)
- Emanuela Occhipinti
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, I-20126 Milano, Italy
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27
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Curley P, van der Does C, Driessen AJM, Kok J, van Sinderen D. Purification and characterisation of a lactococcal aminoacylase. Arch Microbiol 2003; 179:402-8. [PMID: 12682714 DOI: 10.1007/s00203-003-0544-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2002] [Revised: 02/28/2003] [Accepted: 03/10/2003] [Indexed: 11/28/2022]
Abstract
The amd1-encoded aminoacylase from Lactococcus lactis MG1363 was cloned and overexpressed in Escherichia coli and purified. The assumed dimeric enzyme has a subunit molecular mass of about 42 kDa and contains 2.0+/-0.1 g-atoms of zinc and cobalt, in equimolar amounts, per subunit of Amd1. The enzyme was characterised with respect to substrate specificity, pH, temperature and metal dependence. Amd1 exhibited a broad activity range towards N-acetylated- l-amino acids with a strong preference towards those containing neutral aliphatic and aromatic side chains. It hydrolysed N-acetyl- l-alanine most efficiently, and exhibited temperature and pH optima of 30 degrees C and 7.0, respectively. The activity of Amd1 towards N-acetyl- l-alanine was enhanced by the divalent cation Co(2+), while Cd(2+ )inhibited activity. Interestingly, Amd1 was shown to catalyse the hydrolysis of several dipeptides at pH 7.0, although with reduced V(max) values as compared to hydrolysis of N-acetylated- l-amino acids. This characteristic has also biological significance since Amd1 was able to complement a growth deficiency in a L. lactis triple peptidase mutant.
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Affiliation(s)
- Peter Curley
- Department of Microbiology, National University of Ireland, Western Road, Cork, Ireland
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28
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Natsch A, Gfeller H, Gygax P, Schmid J, Acuna G. A specific bacterial aminoacylase cleaves odorant precursors secreted in the human axilla. J Biol Chem 2003; 278:5718-27. [PMID: 12468539 DOI: 10.1074/jbc.m210142200] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human axillary odor is known to be formed upon the action of Corynebacteria sp. on odorless axilla secretions. The known axilla odor determinant 3-methyl-2-hexenoic acid was identified in hydrolyzed axilla secretions along with a chemically related compound, 3-hydroxy-3-methylhexanoic acid. The natural precursors of both these acids were purified from non-hydrolyzed axilla secretions. From liquid chromatography/mass spectrometry analysis, it appeared that the acids are covalently linked to a glutamine residue in fresh axilla secretions, and the corresponding conjugates were synthesized for confirmation. Bacterial isolates obtained from the human axilla and belonging to the Corynebacteria were found to release the acids from these odorless precursors in vitro. A Zn(2+)-dependent aminoacylase mediating this cleavage was purified from Corynebacterium striatum Ax20, and the corresponding gene agaA was cloned and heterologously expressed in Escherichia coli. The enzyme is highly specific for the glutamine residue but has a low specificity for the acyl part of the substrate. agaA is closely related to many genes coding for enzymes involved in the cleavage of N-terminal acyl and aryl substituents from amino acids. This is the first report of the structure elucidation of precursors for human body odorants and the isolation of the bacterial enzyme involved in their cleavage.
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Affiliation(s)
- Andreas Natsch
- Givaudan Dübendorf Ltd., Ueberlandstrasse 138, CH-8600 Duebendorf, Switzerland.
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29
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Affiliation(s)
- William C Nierman
- Institute for Genomic Research, 9712 Medical Center Drive, Rockville, Maryland 20850, USA
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30
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Arndt JW, Hao B, Ramakrishnan V, Cheng T, Chan SI, Chan MK. Crystal structure of a novel carboxypeptidase from the hyperthermophilic archaeon Pyrococcus furiosus. Structure 2002; 10:215-24. [PMID: 11839307 DOI: 10.1016/s0969-2126(02)00698-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The structure of Pyrococcus furiosus carboxypeptidase (PfuCP) has been determined to 2.2 A resolution using multiwavelength anomalous diffraction (MAD) methods. PfuCP represents the first structure of the new M32 family of carboxypeptidases. The overall structure is comprised of a homodimer. Each subunit is mostly helical with its most pronounced feature being a deep substrate binding groove. The active site lies at the bottom of this groove and contains an HEXXH motif that coordinates the metal ion required for catalysis. Surprisingly, the structure is similar to the recently reported rat neurolysin. Comparison of these structures as well as sequence analyses with other homologous proteins reveal several conserved residues. The roles for these conserved residues in the catalytic mechanism are inferred based on modeling and their location.
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Affiliation(s)
- Joseph W Arndt
- Department of Chemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
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31
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Han JS, Kosugi Y, Ishida H, Ishikawa K. Kinetic study of sn-glycerol-1-phosphate dehydrogenase from the aerobic hyperthermophilic archaeon, Aeropyrum pernix K1. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:969-76. [PMID: 11846799 DOI: 10.1046/j.0014-2956.2001.02731.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A gene having high sequence homology (45-49%) with the glycerol-1-phosphate dehydrogenase gene from Methanobacterium thermoautotrophicum was cloned from the aerobic hyperthermophilic archaeon Aeropyrum pernix K1 (JCM 9820). This gene expressed in Escherichia coli with the pET vector system consists of 1113 nucleotides with an ATG initiation codon and a TAG termination codon. The molecular mass of the purified enzyme was estimated to be 38 kDa by SDS/PAGE and 72.4 kDa by gel column chromatography, indicating presence as a dimer. The optimum reaction temperature of this enzyme was observed to be 94-96 degrees C at near neutral pH. This enzyme was subjected to two-substrate kinetic analysis. The enzyme showed substrate specificity for NAD(P)H-dependent dihydroxyacetone phosphate reduction and NAD(+)-dependent glycerol-1-phosphate (Gro1P) oxidation. NADP(+)-dependent Gro1P oxidation was not observed with this enzyme. For the production of Gro1P in A. pernix cells, NADPH is the preferred coenzyme rather than NADH. Gro1P acted as a noncompetitive inhibitor against dihydroxyacetone phosphate and NAD(P)H. However, NAD(P)(+) acted as a competitive inhibitor against NAD(P)H and as a noncompetitive inhibitor against dihydroxyacetone phosphate. This kinetic data indicates that the catalytic reaction by glycerol- 1-phosphate dehydrogenase from A. pernix follows a ordered bi-bi mechanism.
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Affiliation(s)
- Jin-Suk Han
- National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka, Japan
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32
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Story SV, Grunden AM, Adams MW. Characterization of an aminoacylase from the hyperthermophilic archaeon Pyrococcus furiosus. J Bacteriol 2001; 183:4259-68. [PMID: 11418567 PMCID: PMC95316 DOI: 10.1128/jb.183.14.4259-4268.2001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aminoacylase was identified in cell extracts of the hyperthermophilic archaeon Pyrococcus furiosus by its ability to hydrolyze N-acetyl-L-methionine and was purified by multistep chromatography. The enzyme is a homotetramer (42.06 kDa per subunit) and, as purified, contains 1.0 +/- 0.48 g-atoms of zinc per subunit. Treatment of the purified enzyme with EDTA resulted in complete loss of activity. This was restored to 86% of the original value (200 U/mg) by treatment with ZnCl(2) (and to 74% by the addition of CoCl(2)). After reconstitution with ZnCl(2), the enzyme contained 2.85 +/- 0.48 g-atoms of zinc per subunit. Aminoacylase showed broad substrate specificity and hydrolyzed nonpolar N-acylated L amino acids (Met, Ala, Val, and Leu), as well as N-formyl-L-methionine. The high K(m) values for these compounds indicate that the enzyme plays a role in the metabolism of protein growth substrates rather than in the degradation of cellular proteins. Maximal aminoacylase activity with N-acetyl-L-methionine as the substrate occurred at pH 6.5 and a temperature of 100 degrees C. The N-terminal amino acid sequence of the purified aminoacylase was used to identify, in the P. furiosus genome database, a gene that encodes 383 amino acids. The gene was cloned and expressed in Escherichia coli by using two approaches. One involved the T7 lac promoter system, in which the recombinant protein was expressed as inclusion bodies. The second approach used the Trx fusion system, and this produced soluble but inactive recombinant protein. Renaturation and reconstitution experiments with Zn(2+) ions failed to produce catalytically active protein. A survey of databases showed that, in general, organisms that contain a homolog of the P. furiosus aminoacylase (> or = 50% sequence identity) utilize peptide growth substrates, whereas those that do not contain the enzyme are not known to be proteolytic, suggesting a role for the enzyme in primary catabolism.
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Affiliation(s)
- S V Story
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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