1
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Fordjour E, Liu CL, Yang Y, Bai Z. Recent advances in lycopene and germacrene a biosynthesis and their role as antineoplastic drugs. World J Microbiol Biotechnol 2024; 40:254. [PMID: 38916754 DOI: 10.1007/s11274-024-04057-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/17/2024] [Indexed: 06/26/2024]
Abstract
Sesquiterpenes and tetraterpenes are classes of plant-derived natural products with antineoplastic effects. While plant extraction of the sesquiterpene, germacrene A, and the tetraterpene, lycopene suffers supply chain deficits and poor yields, chemical synthesis has difficulties in separating stereoisomers. This review highlights cutting-edge developments in producing germacrene A and lycopene from microbial cell factories. We then summarize the antineoplastic properties of β-elemene (a thermal product from germacrene A), sesquiterpene lactones (metabolic products from germacrene A), and lycopene. We also elaborate on strategies to optimize microbial-based germacrene A and lycopene production.
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Affiliation(s)
- Eric Fordjour
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- National Engineering Research Center of Cereal Fermentation, and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu , 214122, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Chun-Li Liu
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.
- National Engineering Research Center of Cereal Fermentation, and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu , 214122, China.
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China.
| | - Yankun Yang
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- National Engineering Research Center of Cereal Fermentation, and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu , 214122, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Zhonghu Bai
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- National Engineering Research Center of Cereal Fermentation, and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu , 214122, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
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2
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Planas-Iglesias J, Marques SM, Pinto GP, Musil M, Stourac J, Damborsky J, Bednar D. Computational design of enzymes for biotechnological applications. Biotechnol Adv 2021; 47:107696. [PMID: 33513434 DOI: 10.1016/j.biotechadv.2021.107696] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 12/14/2022]
Abstract
Enzymes are the natural catalysts that execute biochemical reactions upholding life. Their natural effectiveness has been fine-tuned as a result of millions of years of natural evolution. Such catalytic effectiveness has prompted the use of biocatalysts from multiple sources on different applications, including the industrial production of goods (food and beverages, detergents, textile, and pharmaceutics), environmental protection, and biomedical applications. Natural enzymes often need to be improved by protein engineering to optimize their function in non-native environments. Recent technological advances have greatly facilitated this process by providing the experimental approaches of directed evolution or by enabling computer-assisted applications. Directed evolution mimics the natural selection process in a highly accelerated fashion at the expense of arduous laboratory work and economic resources. Theoretical methods provide predictions and represent an attractive complement to such experiments by waiving their inherent costs. Computational techniques can be used to engineer enzymatic reactivity, substrate specificity and ligand binding, access pathways and ligand transport, and global properties like protein stability, solubility, and flexibility. Theoretical approaches can also identify hotspots on the protein sequence for mutagenesis and predict suitable alternatives for selected positions with expected outcomes. This review covers the latest advances in computational methods for enzyme engineering and presents many successful case studies.
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Affiliation(s)
- Joan Planas-Iglesias
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Sérgio M Marques
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Gaspar P Pinto
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Milos Musil
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic; IT4Innovations Centre of Excellence, Faculty of Information Technology, Brno University of Technology, 61266 Brno, Czech Republic
| | - Jan Stourac
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic.
| | - David Bednar
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic.
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3
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Cappiello M, Balestri F, Moschini R, Mura U, Del-Corso A. Intra-site differential inhibition of multi-specific enzymes. J Enzyme Inhib Med Chem 2020; 35:840-846. [PMID: 32208768 PMCID: PMC7144184 DOI: 10.1080/14756366.2020.1743988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/12/2020] [Accepted: 03/12/2020] [Indexed: 12/17/2022] Open
Abstract
The ability to catalyse a reaction acting on different substrates, known as "broad-specificity" or "multi-specificity", and to catalyse different reactions at the same active site ("promiscuity") are common features among the enzymes. These properties appear to go against the concept of extreme specificity of the catalytic action of enzymes and have been re-evaluated in terms of evolution and metabolic adaptation. This paper examines the potential usefulness of a differential inhibitory action in the study of the susceptibility to inhibition of multi-specific or promiscuous enzymes acting on different substrates. Aldose reductase is a multi-specific enzyme that catalyses the reduction of both aldoses and hydrophobic cytotoxic aldehydes and is used here as a concrete case to deal with the differential inhibition approach.
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Affiliation(s)
- Mario Cappiello
- Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Pisa, Italy
| | - Francesco Balestri
- Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Pisa, Italy
| | - Roberta Moschini
- Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Pisa, Italy
| | - Umberto Mura
- Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy
| | - Antonella Del-Corso
- Department of Biology, Biochemistry Unit, University of Pisa, Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Pisa, Italy
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4
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Chiu CH, Tsai TY, Yeh YC, Wang R. Encapsulation of β-Glucosidase within PVA Fibers by CCD-RSM-Guided Coelectrospinning: A Novel Approach for Specific Mogroside Sweetener Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:11790-11801. [PMID: 32991810 DOI: 10.1021/acs.jafc.0c02513] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Siamenoside I is a rare mogroside in Siraitia grosvenorii Swingle and has become one of the target ingredients in natural sweetener production. However, the complex structure of siamenoside I has hindered its production in various ways. Here, a yeast cell that produces a specific β-glucosidase for siamenoside I conversion from mogroside V was constructed, and the enzymes were coelectrospun with poly(vinyl alcohol) followed by phenylboronic acid cross-linking to provide potential usage in the batch production process of Siamenoside I. A central composite design (CCD)-response surface methodology (RSM) was used to find the optimum coelectrospinning parameters. The pH stability and sodium dodecyl sulfate tolerance increased for the entrapped enzymes, and positive correlations between the fiber diameter and enzymatic activity were confirmed. The batch process showed an average siamenoside I production rate of 118 ± 0.08 mg L-1 h-1 per gram of fiber. This is the first research article showing specific siamenoside I production on enzyme-loaded electrospun fibers.
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Affiliation(s)
- Chun-Hui Chiu
- Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Keelung City, Taiwan
- Graduate Institute of Health Industry and Technology, Research Center for Chinese Herbal Medicine and Research Center for Food and Cosmetic Safety, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan City, Taiwan
| | - Tsan-Yu Tsai
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei City, Taiwan
| | - Yi-Cheun Yeh
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei City, Taiwan
| | - Reuben Wang
- Department of Food Science, College of Agriculture, Tunghai University, Taichung City, Taiwan
- Institute of Food Safety and Health, College of Public Health, National Taiwan University, Taipei City, Taiwan
- Master of Public Health Program, College of Public Health, National Taiwan University, Taipei City, Taiwan
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5
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Janzen E, Blanco C, Peng H, Kenchel J, Chen IA. Promiscuous Ribozymes and Their Proposed Role in Prebiotic Evolution. Chem Rev 2020; 120:4879-4897. [PMID: 32011135 PMCID: PMC7291351 DOI: 10.1021/acs.chemrev.9b00620] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
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The ability of enzymes,
including ribozymes, to catalyze side reactions
is believed to be essential to the evolution of novel biochemical
activities. It has been speculated that the earliest ribozymes, whose
emergence marked the origin of life, were low in activity but high
in promiscuity, and that these early ribozymes gave rise to specialized
descendants with higher activity and specificity. Here, we review
the concepts related to promiscuity and examine several cases of highly
promiscuous ribozymes. We consider the evidence bearing on the question
of whether de novo ribozymes would be quantitatively
more promiscuous than later evolved ribozymes or protein enzymes.
We suggest that while de novo ribozymes appear to
be promiscuous in general, they are not obviously more promiscuous
than more highly evolved or active sequences. Promiscuity is a trait
whose value would depend on selective pressures, even during prebiotic
evolution.
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Affiliation(s)
- Evan Janzen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Celia Blanco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Huan Peng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Josh Kenchel
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Irene A Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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6
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Khan M, Seto D, Subramaniam R, Desveaux D. Oh, the places they'll go! A survey of phytopathogen effectors and their host targets. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:651-663. [PMID: 29160935 DOI: 10.1111/tpj.13780] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/03/2017] [Accepted: 11/07/2017] [Indexed: 05/09/2023]
Abstract
Phytopathogens translocate effector proteins into plant cells where they sabotage the host cellular machinery to promote infection. An individual pathogen can translocate numerous distinct effectors during the infection process to target an array of host macromolecules (proteins, metabolites, DNA, etc.) and manipulate them using a variety of enzymatic activities. In this review, we have surveyed the literature for effector targets and curated them to convey the range of functions carried out by phytopathogenic proteins inside host cells. In particular, we have curated the locations of effector targets, as well as their biological and molecular functions and compared these properties across diverse phytopathogens. This analysis validates previous observations about effector functions (e.g. immunosuppression), and also highlights some interesting features regarding effector specificity as well as functional diversification of phytopathogen virulence strategies.
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Affiliation(s)
- Madiha Khan
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Derek Seto
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Rajagopal Subramaniam
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
- Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada, KW Neatby bldg, 960 Carling Ave., Ottawa, ON, K1A 0C6, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
- Centre for the Analysis of Genome Function and Evolution, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
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7
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Ahsan MM, Jeon H, P. Nadarajan S, Chung T, Yoo HW, Kim BG, Patil MD, Yun H. Biosynthesis of the Nylon 12 Monomer, ω-Aminododecanoic Acid with Novel CYP153A, AlkJ, and ω-TA Enzymes. Biotechnol J 2018; 13:e1700562. [DOI: 10.1002/biot.201700562] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/05/2017] [Indexed: 11/11/2022]
Affiliation(s)
| | - Hyunwoo Jeon
- Department of Systems Biotechnology; Konkuk University; 120 Neungdong-ro Gwangjin-gu Seoul-050-29 South Korea
| | - Saravanan P. Nadarajan
- Department of Systems Biotechnology; Konkuk University; 120 Neungdong-ro Gwangjin-gu Seoul-050-29 South Korea
| | - Taeowan Chung
- School of Biotechnology; Yeungnam University; Gyeongsan 38541 South Korea
| | - Hee-Wang Yoo
- School of Chemical and Biological Engineering; Seoul National University; Seoul 08826 South Korea
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering; Seoul National University; Seoul 08826 South Korea
| | - Mahesh D. Patil
- Department of Systems Biotechnology; Konkuk University; 120 Neungdong-ro Gwangjin-gu Seoul-050-29 South Korea
| | - Hyungdon Yun
- Department of Systems Biotechnology; Konkuk University; 120 Neungdong-ro Gwangjin-gu Seoul-050-29 South Korea
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8
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Evolution acting on the same target, but at multiple levels: Proteins as the test case. J Biosci 2017; 42:1-3. [DOI: 10.1007/s12038-017-9672-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Atkins WM. Biological messiness vs. biological genius: Mechanistic aspects and roles of protein promiscuity. J Steroid Biochem Mol Biol 2015; 151:3-11. [PMID: 25218442 PMCID: PMC4920067 DOI: 10.1016/j.jsbmb.2014.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/28/2014] [Accepted: 09/09/2014] [Indexed: 02/06/2023]
Abstract
In contrast to the traditional biological paradigms focused on 'specificity', recent research and theoretical efforts have focused on functional 'promiscuity' exhibited by proteins and enzymes in many biological settings, including enzymatic detoxication, steroid biochemistry, signal transduction and immune responses. In addition, divergent evolutionary processes are apparently facilitated by random mutations that yield promiscuous enzyme intermediates. The intermediates, in turn, provide opportunities for further evolution to optimize new functions from existing protein scaffolds. In some cases, promiscuity may simply represent the inherent plasticity of proteins resulting from their polymeric nature with distributed conformational ensembles. Enzymes or proteins that bind or metabolize noncognate substrates create 'messiness' or noise in the systems they contribute to. With our increasing awareness of the frequency of these promiscuous behaviors it becomes interesting and important to understand the molecular bases for promiscuous behavior and to distinguish between evolutionarily selected promiscuity and evolutionarily tolerated messiness. This review provides an overview of current understanding of these aspects of protein biochemistry and enzymology.
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Affiliation(s)
- William M Atkins
- Department of Medicinal Chemistry, Box 357610, University of Washington, Seattle, WA 98195-7610, USA.
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10
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Monillas ES, Caplan JL, Thévenin AF, Bahnson BJ. Oligomeric state regulated trafficking of human platelet-activating factor acetylhydrolase type-II. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:469-75. [PMID: 25707358 DOI: 10.1016/j.bbapap.2015.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/06/2015] [Accepted: 02/12/2015] [Indexed: 01/19/2023]
Abstract
The intracellular enzyme platelet-activating factor acetylhydrolase type-II (PAFAH-II) hydrolyzes platelet-activating factor and oxidatively fragmented phospholipids. PAFAH-II in its resting state is mainly cytoplasmic, and it responds to oxidative stress by becoming increasingly bound to endoplasmic reticulum and Golgi membranes. Numerous studies have indicated that this enzyme is essential for protecting cells from oxidative stress induced apoptosis. However, the regulatory mechanism of the oxidative stress response by PAFAH-II has not been fully resolved. Here, changes to the oligomeric state of human PAFAH-II were investigated as a potential regulatory mechanism toward enzyme trafficking. Native PAGE analysis in vitro and photon counting histogram within live cells showed that PAFAH-II is both monomeric and dimeric. A Gly-2-Ala site-directed mutation of PAFAH-II demonstrated that the N-terminal myristoyl group is required for homodimerization. Additionally, the distribution of oligomeric PAFAH-II is distinct within the cell; homodimers of PAFAH-II were localized to the cytoplasm while monomers were associated to the membranes of the endoplasmic reticulum and Golgi. We propose that the oligomeric state of PAFAH-II drives functional protein trafficking. PAFAH-II localization to the membrane is critical for substrate acquisition and effective oxidative stress protection. It is hypothesized that the balance between monomer and dimer serves as a regulatory mechanism of a PAFAH-II oxidative stress response.
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Affiliation(s)
- Elizabeth S Monillas
- Department of Chemistry & Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Jeffrey L Caplan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Anastasia F Thévenin
- Department of Chemistry & Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Brian J Bahnson
- Department of Chemistry & Biochemistry, University of Delaware, Newark, DE 19716, USA.
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11
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Chufan EE, Kapoor K, Sim HM, Singh S, Talele TT, Durell SR, Ambudkar SV. Multiple transport-active binding sites are available for a single substrate on human P-glycoprotein (ABCB1). PLoS One 2013; 8:e82463. [PMID: 24349290 PMCID: PMC3857843 DOI: 10.1371/journal.pone.0082463] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/24/2013] [Indexed: 01/07/2023] Open
Abstract
P-glycoprotein (Pgp, ABCB1) is an ATP-Binding Cassette (ABC) transporter that is associated with the development of multidrug resistance in cancer cells. Pgp transports a variety of chemically dissimilar amphipathic compounds using the energy from ATP hydrolysis. In the present study, to elucidate the binding sites on Pgp for substrates and modulators, we employed site-directed mutagenesis, cell- and membrane-based assays, molecular modeling and docking. We generated single, double and triple mutants with substitutions of the Y307, F343, Q725, F728, F978 and V982 residues at the proposed drug-binding site with cys in a cysless Pgp, and expressed them in insect and mammalian cells using a baculovirus expression system. All the mutant proteins were expressed at the cell surface to the same extent as the cysless wild-type Pgp. With substitution of three residues of the pocket (Y307, Q725 and V982) with cysteine in a cysless Pgp, QZ59S-SSS, cyclosporine A, tariquidar, valinomycin and FSBA lose the ability to inhibit the labeling of Pgp with a transport substrate, [125I]-Iodoarylazidoprazosin, indicating these drugs cannot bind at their primary binding sites. However, the drugs can modulate the ATP hydrolysis of the mutant Pgps, demonstrating that they bind at secondary sites. In addition, the transport of six fluorescent substrates in HeLa cells expressing triple mutant (Y307C/Q725C/V982C) Pgp is also not significantly altered, showing that substrates bound at secondary sites are still transported. The homology modeling of human Pgp and substrate and modulator docking studies support the biochemical and transport data. In aggregate, our results demonstrate that a large flexible pocket in the Pgp transmembrane domains is able to bind chemically diverse compounds. When residues of the primary drug-binding site are mutated, substrates and modulators bind to secondary sites on the transporter and more than one transport-active binding site is available for each substrate.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/chemistry
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Adenosine Triphosphatases/metabolism
- Adenosine Triphosphate/metabolism
- Binding Sites
- Cell Line, Tumor
- Fluorescent Dyes/chemistry
- Fluorescent Dyes/metabolism
- Gene Expression
- HeLa Cells
- Humans
- Hydrolysis
- Models, Molecular
- Molecular Docking Simulation
- Mutagenesis, Site-Directed
- Protein Binding
- Protein Conformation
- Protein Interaction Domains and Motifs
- Transduction, Genetic
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Affiliation(s)
- Eduardo E. Chufan
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Khyati Kapoor
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hong-May Sim
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Satyakam Singh
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York, United States of America
| | - Tanaji T. Talele
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York, United States of America
| | - Stewart R. Durell
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Suresh V. Ambudkar
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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