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Oliveira JD, Rodrigues da Silva GH, de Moura LD, Göethel G, Papini JZB, Casadei BR, Ribeiro LNDM, Cabeça LF, Garcia SC, Martinez EF, Tofoli GR, de Paula E. DoE development of ionic gradient liposomes: A successful approach to improve encapsulation, prolong anesthesia and decrease the toxicity of etidocaine. Int J Pharm 2023; 634:122672. [PMID: 36738810 DOI: 10.1016/j.ijpharm.2023.122672] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 01/19/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Etidocaine (EDC) is a long-acting local anesthetic of the aminoamide family whose use was discontinued in 2008 for alleged toxicity issues. Ionic gradient liposomes (IGL) are nanostructured carriers for which an inner/outer gradient of ions increases drug upload. This work describes IGLEDC, a formulation optimized by Design of Experiments, composed of hydrogenated soy phosphatidylcholine:cholesterol:EDC, and characterized by DLS, NTA, TEM/Cryo-TEM, DSC and 1H NMR. The optimized IGL showed significant encapsulation efficiency (41 %), good shelf stability (180 days) and evidence of EDC interaction with the lipid bilayer (as seen by DSC and 1H NMR results) that confirms its membrane permeation. In vitro (release kinetics and cytotoxicity) tests showed that the encapsulation of EDC into the IGL promoted sustained release for 24 h and decreased by 50 % the intrinsic toxicity of EDC to Schwann cells. In vivo IGLEDC decreased the toxicity of EDC to Caenorhabditis elegans by 25 % and extended its anesthetic effect by one hour, after infiltrative administration, at clinically used (0.5 %) concentration, in rats. Thus, this novel drug delivery system is a promise for the possible reintroduction of EDC in clinics, aiming at the control of operative and postoperative pain.
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Affiliation(s)
- Juliana Damasceno Oliveira
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, SP, Brazil
| | | | - Ludmila David de Moura
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, SP, Brazil
| | - Gabriela Göethel
- Toxicology Laboratory, Pharmacy Faculty, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Juliana Z B Papini
- São Leopoldo Mandic Institute and Research Center, Campinas-São Paulo, Brazil
| | | | | | - Luis Fernando Cabeça
- Department of Chemistry, Federal Technological University of Parana, Londrina, PR, Brazil
| | - Solange Cristina Garcia
- Toxicology Laboratory, Pharmacy Faculty, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | | | | | - Eneida de Paula
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, SP, Brazil.
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Félix LM, Luzio A, Antunes L, Coimbra AM, Valentim AM. Malformations and mortality in zebrafish early stages associated with elevated caspase activity after 24 h exposure to MS-222. Toxicol Appl Pharmacol 2020; 412:115385. [PMID: 33370555 DOI: 10.1016/j.taap.2020.115385] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/30/2020] [Accepted: 12/22/2020] [Indexed: 01/20/2023]
Abstract
Tricaine methanesulfonate (MS-222) is a commonly used anaesthetic agent for immobilization of aquatic species. However, delayed development and malformations have been observed in 24 hpf (hours post-fertilization) zebrafish embryos after long-term immobilization. Still, no comprehensive study has been described regarding zebrafish exposure to MS-222 during the first hours of development, which are one of the most sensitive life stages to toxicants. Therefore, this research aimed to assess the toxicity of a 24 h exposure to MS-222 on zebrafish embryonic development. Based on the MS-222 LC50, early blastula stage embryos (~2 hpf) were exposed to 0, 12.5, 25 and 50 mg L-1 for 24 h and then allowed to develop up to 144 hpf. The chromatographic analysis showed that this anaesthetic agent bioaccumulates in 26 hpf zebrafish larvae in a concentration-dependent manner. In addition, increased mortalities and skeletal abnormalities were observed at 144 hpf, namely in the highest tested concentration. Yet, no craniofacial anomalies were observed either by alcian blue or calcein staining methods. Independently of the tested concentration, decreased speed and distance travelled were perceived in 144 hpf larvae. At the biochemical level, decreased in vivo reactive oxygen species (ROS) generation and apoptosis was observed. Additionally, catalase activity was increased at 26 hpf while results of mRNA expression showed a decreased gclc transcript content at the same time-point. Overall, data obtained highlight the toxicological risk of MS-222 and support ROS-mediated cell death signalling changes through the elevation of catalase activity as an adaptative or protective response.
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Affiliation(s)
- Luís M Félix
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; Laboratory Animal Science, IBMC - Instituto de Biologia Molecular Celular, Universidade do Porto, Porto, Portugal; Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal.
| | - Ana Luzio
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal; School of Life and Environmental Sciences (ECVA), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Luís Antunes
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal; School of Agrarian and Veterinary Sciences (ECAV), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Ana M Coimbra
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal; School of Life and Environmental Sciences (ECVA), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Ana M Valentim
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; Laboratory Animal Science, IBMC - Instituto de Biologia Molecular Celular, Universidade do Porto, Porto, Portugal; Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
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3
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Zeballos JL, Strichartz GR. Tuning Up the Life Saver. Anesth Analg 2019; 128:199-201. [DOI: 10.1213/ane.0000000000003863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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4
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Oliveira JD, Ribeiro LNDM, Rodrigues da Silva GH, Casadei BR, Couto VM, Martinez EF, de Paula E. Sustained Release from Ionic-Gradient Liposomes Significantly Decreases ETIDOCAINE Cytotoxicity. Pharm Res 2018; 35:229. [DOI: 10.1007/s11095-018-2512-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/27/2018] [Indexed: 12/18/2022]
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Encapsulation of ropivacaine in a combined (donor-acceptor, ionic-gradient) liposomal system promotes extended anesthesia time. PLoS One 2017; 12:e0185828. [PMID: 28982145 PMCID: PMC5628885 DOI: 10.1371/journal.pone.0185828] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 09/20/2017] [Indexed: 11/25/2022] Open
Abstract
Ropivacaine is a local anesthetic with similar potency but lower systemic toxicity than bupivacaine, the most commonly used spinal anesthetic. The present study concerns the development of a combined drug delivery system for ropivacaine, comprised of two types of liposomes: donor multivesicular vesicles containing 250 mM (NH4)2SO4 plus the anesthetic, and acceptor large unilamellar vesicles with internal pH of 5.5. Both kinds of liposomes were composed of hydrogenated soy-phosphatidylcholine:cholesterol (2:1 mol%) and were prepared at pH 7.4. Dynamic light scattering, transmission electron microscopy and electron paramagnetic resonance techniques were used to characterize the average particle size, polydispersity, zeta potential, morphology and fluidity of the liposomes. In vitro dialysis experiments showed that the combined liposomal system provided significantly longer (72 h) release of ropivacaine, compared to conventional liposomes (~45 h), or plain ropivacaine (~4 h) (p <0.05). The pre-formulations tested were significantly less toxic to 3T3 cells, with toxicity increasing in the order: combined system < ropivacaine in donor or acceptor liposomes < ropivacaine in conventional liposomes < plain ropivacaine. The combined formulation, containing 2% ropivacaine, increased the anesthesia duration up to 9 h after subcutaneous infiltration in mice. In conclusion, a promising drug delivery system for ropivacaine was described, which can be loaded with large amounts of the anesthetic (2%), with reduced in vitro cytotoxicity and extended anesthesia time.
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Okamoto A, Tanaka M, Sumi C, Oku K, Kusunoki M, Nishi K, Matsuo Y, Takenaga K, Shingu K, Hirota K. The antioxidant N-acetyl cysteine suppresses lidocaine-induced intracellular reactive oxygen species production and cell death in neuronal SH-SY5Y cells. BMC Anesthesiol 2016; 16:104. [PMID: 27776485 PMCID: PMC5078905 DOI: 10.1186/s12871-016-0273-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/14/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The local anesthetic lidocaine can affect intra- and extra-cellular signaling pathways in both neuronal and non-neuronal cells, resulting in long-term modulation of biological functions, including cell growth and death. Indeed, lidocaine was shown to induce necrosis and apoptosis in vitro. While several studies have suggested that lidocaine-induced apoptosis is mitochondrial pathway-dependent, it remains unclear whether reactive oxygen species (ROS) are involved in this process and whether the observed cell death can be prevented by antioxidant treatment. METHODS The effects of lidocaine and antioxidants on cell viability and death were evaluated using SH-SY5Y cells, HeLa cells, and HeLa cell derivatives. Cell viability was examined via MTS/PES ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt]/phenazine ethosulfate) assay. Meanwhile, cell apoptosis and necrosis were evaluated using a cell death detection assay with Annexin V-FITC and PI staining, as well as by assaying for caspase-3/7 and caspase-9 activity, and by measuring the release of lactate dehydrogenase, respectively. Mitochondrial transmembrane potential (ΔΨm) was assessed using the fluorescent probe tetramethylrhodamine ethyl ester. RESULTS Lidocaine treatment resulted in suppression of the mitochondrial electron transport chain and subsequent attenuation of mitochondrial membrane potential, as well as enhanced ROS production, activation of caspase-3/7 and caspase-9, and induction of apoptosis and necrosis in SH-SY5Y cells in a dose- and time-dependent manner. Likewise, the anesthetics mepivacaine and bupivacaine also induced apoptosis in SH-SY5Y cells. Notably, the antioxidants N-acetyl cysteine (NAC) and Trolox successfully scavenged the mitochondria-derived ROS and suppressed local lidocaine-induced cell death. CONCLUSIONS Our findings demonstrate that the local anesthetics lidocaine, mepivacaine, and bupivacaine inhibited the activity of mitochondria and induced apoptosis and necrosis in a dose-dependent manner. Furthermore, they demonstrate that treatment with the antioxidants NAC, Trolox, and GGA resulted in preservation of mitochondrial voltage and inhibition of apoptosis via suppression of caspase activation.
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Affiliation(s)
- Akihisa Okamoto
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Masahiro Tanaka
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Chisato Sumi
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Kanako Oku
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Munenori Kusunoki
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Kenichiro Nishi
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Yoshiyuki Matsuo
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Keizo Takenaga
- Department of Life Science, Shimane University School of Medicine, Izumo, Japan
| | - Koh Shingu
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan
| | - Kiichi Hirota
- Department of Anesthesiology, Kansai Medical University, Hirakata, Japan.
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Keck M, Zeyda M, Burjak S, Kamolz LP, Selig H, Stulnig TM, Frey M. Coenzyme Q10 does not enhance preadipocyte viability in an in vitro lipotransfer model. Aesthetic Plast Surg 2012; 36:453-7. [PMID: 21964747 DOI: 10.1007/s00266-011-9823-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 09/11/2011] [Indexed: 10/17/2022]
Abstract
BACKGROUND Autologous fat is an attractive soft-tissue filler in plastic and reconstructive surgery. The success of the procedure relies strongly on the technique of transferring viable preadipocytes. Among other factors, preadipocyte viability is impaired by local anesthetics. Application of coenzyme Q10 is being performed by aesthetic plastic surgeons to enhance the success of lipotransfer. The aim of this study was to evaluate the effect of Q10 on preadipocyte viability with special regard to impairment after lidocaine treatment. METHODS Preadipocytes were pretreated with coenzyme Q10 or vehicle control followed by incubation with lidocaine for 30 min. Viability and apoptosis were assessed by FACS analysis and Western blot. RESULTS Coenzyme Q10 did not improve viability nor have any effect on investigated apoptosis parameters. Preadipocyte viability was reduced after lidocaine treatment. Surface binding of annexin V, cleavage of caspase-3, and abundance of subdiploid cells were not detectable though, suggesting that necrosis rather than apoptosis is the cause for reduced preadipocyte viability. CONCLUSION Our results indicate that Q10 does not improve preadipocyte viability. Preadipocyte cell death induced by lidocaine is not caused by apoptosis but by necrosis, which cannot be prevented by coenzyme Q10. These findings should be taken into account when searching for solutions to improve preadipocyte viability in the context of soft tissue engineering and autologous fat transfer.
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Peropadre A, Fernández Freire P, Herrero Ó, Pérez Martín JM, Hazen MJ. Cellular Responses Associated with Dibucaine-Induced Phospholipidosis. Chem Res Toxicol 2011; 24:185-92. [DOI: 10.1021/tx100262c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Ana Peropadre
- Cellular Toxicology Group, Laboratory A-110, C/Darwin 2, 28049 Madrid, Spain
- Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, Spain
| | - Paloma Fernández Freire
- Cellular Toxicology Group, Laboratory A-110, C/Darwin 2, 28049 Madrid, Spain
- Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, Spain
| | - Óscar Herrero
- Cellular Toxicology Group, Laboratory A-110, C/Darwin 2, 28049 Madrid, Spain
- Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, Spain
| | - José M. Pérez Martín
- Cellular Toxicology Group, Laboratory A-110, C/Darwin 2, 28049 Madrid, Spain
- Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, Spain
| | - M José Hazen
- Cellular Toxicology Group, Laboratory A-110, C/Darwin 2, 28049 Madrid, Spain
- Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, Spain
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9
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Keck M, Zeyda M, Gollinger K, Burjak S, Kamolz LP, Frey M, Stulnig TM. Local anesthetics have a major impact on viability of preadipocytes and their differentiation into adipocytes. Plast Reconstr Surg 2010; 126:1500-1505. [PMID: 21042106 DOI: 10.1097/prs.0b013e3181ef8beb] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Autologous fat transplantation is a well-established technique in surgery. Moreover, the use of preadipocytes in soft-tissue engineering is currently being intensely investigated. Current efforts focus on identifying maneuvers that may minimize resorption and provide predictable late results. The aim of this study was to investigate the influence of different local anesthetics frequently used in clinical practice on the viability of preadipocytes and their ability to differentiate into adipocytes. METHODS Human preadipocytes were isolated from subcutaneous adipose tissue of 15 patients and treated with bupivacaine, mepivacaine, ropivacaine, articaine/epinephrine, and lidocaine for 30 minutes. Viability was determined directly after treatment and during the ensuing cultivation. Differentiation of preadipocytes was determined by expression of the adipocyte marker adiponectin. RESULTS Although the immediate effects of mepivacaine and ropivacaine were only moderate, treatment with articaine/epinephrine and lidocaine strongly impaired preadipocyte viability. Cells normally attached to the culture dishes and proliferated irrespective of the previous treatment. During long-term cultivation, articaine/epinephrine-treated cell viability decreased markedly, whereas other local anesthetics had no impact. Despite normal phenotypic appearance of cells treated with bupivacaine, mepivacaine, ropivacaine, and lidocaine, all local anesthetics markedly impaired adipocyte differentiation as determined by adiponectin expression. CONCLUSIONS The authors' results show that there is a marked influence of local anesthetics not only on the quantity but also on the quality of viable preadipocytes as determined by their ability to differentiate into mature adipocytes. Therefore, these results should be considered in the context of autologous fat transfer and soft-tissue engineering.
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Affiliation(s)
- Maike Keck
- Vienna, Austria From the Division of Plastic and Reconstructive Surgery, Department of Surgery, and the Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University Vienna
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Werdehausen R, Fazeli S, Braun S, Hermanns H, Essmann F, Hollmann MW, Bauer I, Stevens MF. Apoptosis induction by different local anaesthetics in a neuroblastoma cell line. Br J Anaesth 2009; 103:711-8. [PMID: 19700777 DOI: 10.1093/bja/aep236] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- R Werdehausen
- Department of Anaesthesiology, University of Düsseldorf, Düsseldorf, Germany
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11
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Lazar C, Kluczyk A, Kiyota T, Konishi Y. Drug Evolution Concept in Drug Design: 1. Hybridization Method†. J Med Chem 2004; 47:6973-82. [PMID: 15615546 DOI: 10.1021/jm049637+] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel concept, "drug evolution", is proposed to develop chemical libraries that have a high probability of finding drugs or drug candidates. It converts biological evolution into chemical evolution. In this paper, we present "hybridization" drug evolution, which is the equivalent of sexual recombination of parental genomes in biological evolution. The hybridization essentially shuffles the building blocks of the parent drugs and ought to drug(s); no drug evolution can otherwise occur. We hybridized two drugs, benzocaine and metoclopramide and generated 16 molecules that include the parent drugs, four known drugs, and two molecules whose therapeutic activities are reported. The unusually high number of drugs and drug candidates in the library encourages high expectations of finding new drug(s) or drug candidate(s) within the remaining eight compounds. Interestingly, the therapeutic applications of the eight drugs or drug candidates in the library are fairly diverse as 38 therapeutic applications and 25 molecular targets are counted. Therefore, the library fits as a general chemical library for unspecified therapeutic activities. The hybridization of other two drugs, aspirin and cresotamide, is also described to demonstrate the generality of the method.
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Affiliation(s)
- Carmen Lazar
- Biotechnology Research Institute, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2
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García JJ, Gómez-Puyou A, de Gómez-Puyou MT. Unisite hydrolysis of [gamma 32 P]ATP by soluble mitochondrial F1-ATPase and its release by excess ADP and ATP. Effect of trifluoperazine. J Bioenerg Biomembr 1997; 29:61-70. [PMID: 9067803 DOI: 10.1023/a:1022463822929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Some of the characteristics of unisite hydrolysis of [gamma 32P]ATP as well as the changes that occur on the transition to multisite catalysis were further studied. It was found that a fraction of [gamma 32P]ATP bound at the catalytic sites of F1 under unisite conditions undergoes both hydrolysis and release induced by medium nucleotides upon addition of millimolar concentrations of ADP or ATP. The fraction of [gamma 32P]ATP that undergoes release is similar to the fraction that undergoes hydrolytic cleavage, indicating that the rates of the release and hydrolytic reactions of bound [gamma 32P]ATP are in the same range. As part of studies on the mechanisms through which trifluoperazine inhibits ATP hydrolysis, its effect on unisite hydrolysis of [gamma 32P]ATP was also studied. Trifluoperazine diminishes the rate of unisite hydrolysis by 30-40%. The inhibition is accompanied by a nearly tenfold increase in the ratio of [gamma 32P]ATP/32Pi bound at the catalytic site and a 50% diminution in the rate of 32Pi release from the enzyme into the media. Trifluoperazine also induces heterogeneity of the three catalytic sites of F1 in the sense that in a fraction of F1 molecules, the high-affinity catalytic site has a turnover rate lower than the other two. Trifluoperazine does not modify the release of previously bound [gamma 32P]ATP induced by medium nucleotides. The latter indicates that hindrances in the release of Pi do not necesarily accompany alterations in the release of ATP even though both species lie in the same site.
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Affiliation(s)
- J J García
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. México
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Zhuo S, Paik SR, Register JA, Allison WS. Photoinactivation of the bovine heart mitochondrial F1-ATPase by [14C]dequalinium cross-links phenylalanine-403 or phenylalanine-406 of an alpha subunit to a site or sites contained within residues 440-459 of a beta subunit. Biochemistry 1993; 32:2219-27. [PMID: 8443163 DOI: 10.1021/bi00060a013] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Synthesis of [14C]dequalinium, 1,1'-(1,10-[1,10-14C]decanediyl)bis[4-amino-2-methylquinolinium ], is described, which photoinactivates the bovine heart mitochondrial F1-ATPase (MF1). Maximal photoinactivation occurs on incorporation of about 1.5 mol of [14C]dequalinium/mol of MF1. Three radioactive species were resolved when photoinactivated enzyme was submitted to polyacrylamide gel electrophoresis at pH 4.0 in the presence of tetradecyltrimethylammonium bromide, which correspond to the alpha and beta subunits and a cross-linked species with an M(r) of 116,000. Fractionation of a tryptic digest of photoinactivated enzyme by high-performance liquid chromatography led to isolation of a radioactive peptide which contains residues 399-420 of a alpha subunit. Two fragments containing equal amounts of radioactivity were obtained on fractionation of an endoproteinase Asp-N digest of the isolated radioactive tryptic peptide by high-performance liquid chromatography. Amino acid sequence analysis showed that both fragments contained residues 399-408 of the alpha subunit, but one was missing Phe-alpha 403 and the other was lacking Phe-alpha 406. Fractionation of a cyanogen bromide digest of photoinactivated enzyme followed by trypsin digestion of partially purified cyanogen bromide fragments and fractionation of the resulting radioactive tryptic fragments yielded several radioactive species comprised of residues 399-420 of the alpha subunit cross-linked to residues 440-459 of the beta subunit and a radioactive fragment containing residues 399-420 of the alpha subunit. Partial sequence analyses of the cross-linked fragments suggest that Phe-alpha 403 and Phe-alpha 406 participate in cross-links, whereas no information was obtained on the site or sites of cross-linking in the beta subunit fragment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Zhuo
- Department of Chemistry, University of California, San Diego, La Jolla 92093-0601
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Abstract
Cyclophosphamide (CP; 2.5-10.0 mM) reversibly inhibits acetylcholinesterase (AChE) activity of chicken brain (58-84%) in a concentration-dependent manner, the IC50 (the concentration causing 50% inhibition) being about 2.0 mM. Lineweaver-Burk plots indicated that the nature of this inhibition is mixed; intercept and slope replots are straight lines, showing that the inhibition is complete rather than partial. The value of Km for AChE is found to be 108 microM, while values of KI and Ki are found to be 1.5 and 5.1 mM, respectively, Ki is greater than KI indicating that uncompetitive inhibition is predominant over noncompetitive inhibition.
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Affiliation(s)
- A A al-Jafari
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
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15
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Abstract
Dibucaine-HCl inhibited mitochondrial cytochrome c oxidase activity in intact mitochondria with 50% inhibition occurring at 1.1 mM dibucaine-HCl. Dibucaine-HCl did not prevent the reduction of cytochrome oxidase by ascorbate plus N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD) when measured at 604 nm but prevented 50% of the absorbance change at 445 nm; dithionite reduced the oxidase completely. Dibucaine prevented binding of CO to oxidase reduced with ascorbate plus TMPD by preventing the reduction of cytochrome a3. The midpotenials of cytochrome c and cytochrome oxidase, the visible absorbance wavelength maxima, and the position and intensity of the signals of the EPR spectrum of the oxidase were not affected. Dibucaine-HCl prevented ascorbate plus TMPD-driven reduction of the near infra-red detectable copper center associated with cytochrome a: dithionite subsequently reduced this center. Dibucaine-HCl inhibited cytochrome oxidase activity by interacting between cytochrome a and its associated copper. Since respiration was 8-fold less sensitive in submitochondrial particles, this site of inhibition is on the cytoplasmic side of the membrane.
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Affiliation(s)
- B K Stringer
- Department of Zoology, Oklahoma State University, Stillwater 74078
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16
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Bullough DA, Ceccarelli EA, Roise D, Allison WS. Inhibition of the bovine-heart mitochondrial F1-ATPase by cationic dyes and amphipathic peptides. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 975:377-83. [PMID: 2527062 DOI: 10.1016/s0005-2728(89)80346-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The bovine heart mitochondrial F1-ATPase is inhibited by a number of amphiphilic cations. The order of effectiveness of non-peptidyl inhibitors examined as assessed by the concentration estimated to produce 50% inhibition (I0.5) of the enzyme at pH 8.0 is: dequalinium (8 microM), rhodamine 6G (10 microM), malachite green (14 microM), rosaniline (15 microM) greater than acridine orange (180 microM) greater than rhodamine 123 (270 microM) greater than rhodamine B (475 microM), coriphosphine (480 microM) greater than safranin O (1140 microM) greater than pyronin Y (1650 microM) greater than Nile blue A (greater than 2000 microM). The ATPase activity was also inhibited by the following cationic, amphiphilic peptides: the bee venom peptide, melittin; a synthetic peptide corresponding to the presence of yeast cytochrome oxidase subunit IV (WT), and amphiphilic, synthetic peptides which have been shown (Roise, D., Franziska, T., Horvath, S.J., Tomich, J.M., Richards, J.H., Allison, D.S. and Schatz, G. (1988) EMBO J. 7, 649-653) to function in mitochondrial import when attached to dihydrofolate reductase (delta 11.12, Syn-A2, and Syn-C). The order of effectiveness of the peptide inhibitors as assessed by I0.5 values is: Syn-A2 (40 nM), Syn-C (54 nM) greater than melittin (5 microM) greater than WT (16 microM) greater than delta 11,12 (29 microM). Rhodamines B and 123, dequalinium, melittin, and Syn-A2 showed noncompetitive inhibition, whereas each of the other inhibitors examined (rhodamine 6G, rosaniline, malachite green, coriphosphine, acridine orange, and-Syn-C) showed mixed inhibition. Replots of slopes and intercepts from Lineweaver-Burk plots obtained for dequalinium were hyperbolic indicating partial inhibition. With the exception of Syn-C, for which the slope replot was hyperbolic and the intercept replot was parabolic, steady-state kinetic analyses indicated that inhibition by the other inhibitors was complete. The inhibition constants obtained by steady-state kinetic analyses were in agreement with the I0.5 values estimated for each inhibitor examined. Rhodamine 6G, rosaniline, dequalinium, melittin, Syn-A2, and Syn-C were observed to protect F1 against inactivation by the aziridinium of quinacrine mustard in accord with their experimentally determined I0.5 values.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- D A Bullough
- Department of Chemistry, University of California, San Diego, La Jolla 92093
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Localization of Sites Modified during Inactivation of the Bovine Heart Mitochondrial F1-ATPase by Quinacrine Mustard Using [3H]Aniline as a Probe. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60508-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Gruber HJ, Low PS. Interaction of amphiphiles with integral membrane proteins. I. Structural destabilization of the anion transport protein of the erythrocyte membrane by fatty acids, fatty alcohols, and fatty amines. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 944:414-24. [PMID: 3179297 DOI: 10.1016/0005-2736(88)90512-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effect of model amphiphiles on the structural stability of the anion exchange protein (band 3) of the human erythrocyte membrane was studied by differential scanning calorimetry. The concentration of membranes, as well as the concentration, head group, alkyl chain length, degree of unsaturation, and double bond configuration of a variety of alkane derivatives were all varied in a systematic way. The depression of the denaturation temperature of band 3 per unit membrane concentration of the amphiphile was then determined in order to quantitate the potency of each drug. Saturated fatty acids of chain length C8 to C24 displayed a monotonic decrease in potency up to C20, followed by a dramatic diminution in potency at C22 and C24. Unsaturation caused only minor increases in the abilities of fatty acids to perturb the anion exchanger, and surprisingly, there was neither a trend for the number of double bonds nor a significant cis-trans distinction. Arachidonic acid, as an exception, was much more effective than any other amphiphile in destabilizing band 3. Fatty acids were about three times more potent than fatty amines and fatty alcohols; however, the enhanced partitioning of the latter into the membrane compensated at certain membrane/buffer ratios for its reduced intrinsic potency. A quantitative model interpretation of the data is presented in an accompanying paper.
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Affiliation(s)
- H J Gruber
- Department of Chemistry, Purdue University, West Lafayette, IN
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Vanderkooi G, Adade AB. Stoichiometry and dissociation constants for interaction of tetracaine with mitochondrial adenosinetriphosphatase as determined by fluorescence. Biochemistry 1986; 25:7118-24. [PMID: 2948556 DOI: 10.1021/bi00370a054] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The stoichiometry and dissociation constants for the interaction of tetracaine with chloroform-released ATPase prepared from beef heart mitochondria were determined from the enhancement of tetracaine fluorescence intensity that occurs upon binding. There is a single class of approximately 60 thermodynamically equivalent binding sites on ATPase for tetracaine; these have a microscopic dissociation constant of 4.9 X 10(-4) M at 25 degrees C under solvent conditions that are similar to those used for enzyme assay. Analysis of enzyme kinetic data according to a partial noncompetitive scheme gave an inhibitor constant for tetracaine of 4.8 X 10(-4) M. The numerical agreement between the dissociation constant and the inhibitor constant shows that the filling of the same class of sites is probably responsible for both the enzyme inhibition and the fluorescence enhancement. The sites are hydrophobic, as evidenced by the blue shift and the magnitude of the fluorescence enhancement that occur upon binding.
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