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Francis SM, Pattar Kadavan S, Natesh R. Oligomerization states of the Mycobacterium tuberculosis RNA polymerase core and holoenzymes. Arch Microbiol 2024; 206:230. [PMID: 38649511 DOI: 10.1007/s00203-024-03955-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024]
Abstract
During the past few decades, a wealth of knowledge has been made available for the transcription machinery in bacteria from the structural, functional and mechanistic point of view. However, comparatively little is known about the homooligomerization of the multisubunit M. tuberculosis RNA polymerase (RNAP) enzyme and its functional relevance. While E. coli RNAP has been extensively studied, many aspects of RNAP of the deadly pathogenic M. tuberculosis are still unclear. We used biophysical and biochemical methods to study the oligomerization states of the core and holoenzymes of M. tuberculosis RNAP. By size exclusion chromatography and negative staining Transmission Electron Microscopy (TEM) studies and quantitative analysis of the TEM images, we demonstrate that the in vivo reconstituted RNAP core enzyme (α2ββ'ω) can also exist as dimers in vitro. Using similar methods, we also show that the holoenzyme (core + σA) does not dimerize in vitro and exist mostly as monomers. It is tempting to suggest that the oligomeric changes that we see in presence of σA factor might have functional relevance in the cellular process. Although reported previously in E. coli, to our knowledge we report here for the first time the study of oligomeric nature of M. tuberculosis RNAP in presence and absence of σA factor.
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Affiliation(s)
- Sandrea Maureen Francis
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, 695551, India
| | - Shehna Pattar Kadavan
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, 695551, India
| | - Ramanathan Natesh
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, 695551, India.
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Wang S, Dong ZY, Yan YB. Semi holoenzyme optimizes activity and stability of a hyperthermostable iron-superoxide dismutase. Biochem Biophys Res Commun 2019; 519:93-99. [PMID: 31477266 DOI: 10.1016/j.bbrc.2019.08.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 08/24/2019] [Indexed: 10/26/2022]
Abstract
Metal ion coordination is an essential step for the maturation of metalloenzymes. Generally, the metal coordination sites are thought to be fully occupied to achieve the maximum activity and stability. In this research, we compared the structural features, activity and stability of the apo-, semiholo- and holo-forms of a hyperthermostable tetrameric Fe-superoxide dismutase (SOD). Strikingly, the three forms of enzymes had similar compact tetrameric structures. Removal of iron ions destabilized subunit-subunit interactions during guanidine hydrochloride-induced unfolding. The partially metalized semiholoenzyme possessed most of the activity and identical hyperthermostability of the holoenzyme, but weaker propensity to aggregate. Furthermore, both of the iron content and activity of the semiholoenzyme were unaffected by a 200-fold excess iron ions in solutions, suggesting that conformation of the apo-subunits were forced to the close state by the iron-containing subunits. These observations suggest that fully metalized enzyme is probably nonessential for multimeric metalloenzymes and the semiholoenzyme may be a better choice. The unique properties of semiholoenzyme also provide the organisms a compromised solution to survival under metal deficiency conditions.
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Affiliation(s)
- Sha Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100081, China
| | - Zhi-Yang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100081, China
| | - Yong-Bin Yan
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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Hoffman RM, Yang Z, Tan Y, Han Q, Li S, Yagi S. Safety and Toxicity of Recombinant Methioninase and Polyethylene Glycol (PEG) Recombinant Methioninase in Primates. Methods Mol Biol 2019; 1866:211-229. [PMID: 30725418 DOI: 10.1007/978-1-4939-8796-2_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Methionine (MET) is a general metabolic therapeutic target in cancer, whereby cancer cells have an elevated requirement for MET, termed MET dependence. We have developed recombinant L-methionine α-deamino-γ-mercaptomethane lyase (recombinant methioninase [rMETase, EC 4.4.1.11]) as targeted therapy of all cancer types. Pharmacokinetics, MET depletion, antigenicity, and toxicity of rMETase were examined in macaque monkeys. Pharmacokinetic analysis showed that rMETase was eliminated with a T1/2 of 2.49 h. A 2-week i.v. administration of 4000 units/kg every 8 h/day for 2 weeks resulted in a steady-state depletion of plasma MET to less than 2 μM. The only manifest toxicity was decreased food intake and slight weight loss. Serum albumin and red-cell values declined transiently during treatment. Rechallenge on day 28 resulted in anaphylactic shock and death in one animal. Pretreatment with hydrocortisone prevented the anaphylactic reaction. Anti-rMETase antibodies (at 10-3) were found after the first challenge, increased to 10-6 after the fourth challenge, and decreased to 10-2 by 2 months post-therapy. Therefore, the therapeutic potential of rMETase is limited by its short plasma half-life and immunologic effects, including high antibody production in mice and anaphylactic reactions in monkeys. To overcome these limits, rMETase has been coupled to methoxypolyethylene glycol succinimidyl glutarate polyethylene glycol (MEGC-PEG-5000). The pharmacokinetics, antigenicity, and toxicity of MEGC-PEG-rMETase in macaque monkeys were evaluated using an escalating-dose strategy. In pharmacokinetic studies, a single 4000 units/kg dose showed that MEGC-PEG-rMETase holoenzyme activity was eliminated with a biological half-life of 1.3 h, and the MEGC-PEG-rMETase apoenzyme was eliminated with a biological half-life of 90 h, a 36-fold increase compared with non-PEGylated rMETase. The disparity in the T½ of the apoenzyme and the holoenzyme reflects the loss of co-factor pyridoxal-L-phosphate of the circulating MEGC-PEG-rMETase. A 7-day i.v. administration of 4000 units/kg every 12 h resulted in a steady-state depletion of plasma MET to <5 μmol/L. The only manifest toxicity was decreased food intake and slight weight loss. Red cell values and hemoglobin declined transiently. Subsequent challenges did not result in any immunologic reactions. Anti-MEGC-PEG-rMETase antibodies were 100- to 1000-fold less than antibodies elicited by naked rMETase, thereby suggesting clinical potential of MEGC-PEG-rMETase as a broad anticancer agent.
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Affiliation(s)
- Robert M Hoffman
- AntiCancer, Inc., San Diego, CA, USA.
- Department of Surgery, University of California, San Diego, CA, USA.
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Stasyuk N, Gayda G, Zakalskiy A, Zakalska O, Errachid A, Gonchar M. Highly selective apo-arginase based method for sensitive enzymatic assay of manganese (II) and cobalt (II) ions. Spectrochim Acta A Mol Biomol Spectrosc 2018; 193:349-356. [PMID: 29268235 DOI: 10.1016/j.saa.2017.12.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/27/2017] [Accepted: 12/05/2017] [Indexed: 06/07/2023]
Abstract
A novel enzymatic method of manganese (II) and cobalt (II) ions assay, based on using apo-enzyme of Mn2+-dependent recombinant arginase I (arginase) and 2,3-butanedione monoxime (DMO) as a chemical reagent is proposed. The principle of the method is the evaluation of the activity of L-arginine-hydrolyzing of arginase holoenzyme after the specific binding of Mn2+ or Co2+ with apo-arginase. Urea, which is the product of enzymatic hydrolysis of L-arginine (Arg), reacts with DMO and the resulted compound is detected by both fluorometry and visual spectrophotometry. Thus, the content of metal ions in the tested samples can be determined by measuring the level of urea generated after enzymatic hydrolysis of Arg by reconstructed arginase holoenzyme in the presence of tested metal ions. The linearity range of the fluorometric apo-arginase-DMO method in the case of Mn2+ assay is from 4pM to 1.10nM with a limit of detection of 1pM Mn2+, whereas the linearity range of the present method in the case of Co2+ assay is from 8pM to 45nM with a limit of detection of 2.5pM Co2+. The proposed method being highly sensitive, selective, valid and low-cost, may be useful to monitor Mn2+ and Co2+ content in clinical laboratories, food industry and environmental control service.
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Affiliation(s)
- Nataliya Stasyuk
- Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Str. 14/16, Lviv 79005, Ukraine
| | - Galina Gayda
- Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Str. 14/16, Lviv 79005, Ukraine
| | - Andriy Zakalskiy
- Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Str. 14/16, Lviv 79005, Ukraine
| | - Oksana Zakalska
- Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Str. 14/16, Lviv 79005, Ukraine
| | - Abdelhamid Errachid
- Université de Lyon, Analytical Sciences Institute, UMR CNRS 5180, CNRS, Université de Lyon 1, ENS Lyon, 5 rue de la Doua, F-69100 Villeurbanne Cedex, France
| | - Mykhailo Gonchar
- Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Str. 14/16, Lviv 79005, Ukraine.
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Lee SH, Yu HJ, Lee S, Ryu DY. Characterization of the Gly45Asp variant of human cytochrome P450 1A1 using recombinant expression. Toxicol Lett 2015; 239:81-9. [PMID: 26367467 DOI: 10.1016/j.toxlet.2015.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/22/2015] [Accepted: 09/09/2015] [Indexed: 12/11/2022]
Abstract
Cytochrome P450 1A1 (CYP1A1) is a heme-containing enzyme involved in metabolism of xenobiotics. CYP1A1 containing a Gly45Asp substitution has not yet been characterized. Escherichia coli expressing the Gly45Asp variant, as well as the purified variant protein, had lower CYP (i.e., holoenzyme) contents than their wild-type (WT) equivalents. The purified variant protein had reduced heme contents compared with their WT equivalents. Enhanced supplementation of a heme precursor during culture did not increase CYP content in E. coli expressing the variant, but did for the WT. Substitution of Gly45 with other residues, especially those having large side chains, decreased CYP contents of E. coli expressing the variants to a considerable extent. A 3D structure of CYP1A1 indicates that Gly45, along with other residues of the PR region, interacts with Arg77 of β- strand 1-1, which indirectly interacts with heme. Substitution analyses suggest the importance of residues of the PR region and Arg77 in holoenzyme expression. E. coli membrane and mammalian microsomes expressing the Gly45Asp variant, as well as the purified variant protein, had reduced ethoxyresorufin O-dealkylation activities, compared with the WT equivalents. These findings suggest the Gly45Asp substitution results in a structural disturbance of CYP1A1, reducing its holoenzyme formation and catalytic activity.
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Affiliation(s)
- Seung Heon Lee
- College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, South Korea
| | - Hee Jeong Yu
- College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, South Korea
| | - Seungwoo Lee
- College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, South Korea
| | - Doug-Young Ryu
- College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, South Korea.
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Chen D, Yue H, Spiering MM, Benkovic SJ. Insights into Okazaki fragment synthesis by the T4 replisome: the fate of lagging-strand holoenzyme components and their influence on Okazaki fragment size. J Biol Chem 2013; 288:20807-20816. [PMID: 23729670 DOI: 10.1074/jbc.m113.485961] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we employed a circular replication substrate with a low priming site frequency (1 site/1.1 kb) to quantitatively examine the size distribution and formation pattern of Okazaki fragments. Replication reactions by the T4 replisome on this substrate yielded a patterned series of Okazaki fragments whose size distribution shifted through collision and signaling mechanisms as the gp44/62 clamp loader levels changed but was insensitive to changes in the gp43 polymerase concentration, as expected for a processive, recycled lagging-strand polymerase. In addition, we showed that only one gp45 clamp is continuously associated with the replisome and that no additional clamps accumulate on the DNA, providing further evidence that the clamp departs, whereas the polymerase is recycled upon completion of an Okazaki fragment synthesis cycle. We found no support for the participation of a third polymerase in Okazaki fragment synthesis.
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Affiliation(s)
- Danqi Chen
- From 414, Wartik Laboratories, Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Hongjun Yue
- From 414, Wartik Laboratories, Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Michelle M Spiering
- From 414, Wartik Laboratories, Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Stephen J Benkovic
- From 414, Wartik Laboratories, Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802.
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