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Shi Y, Lu S, Zhou X, Wang X, Zhang C, Wu N, Dong T, Xing S, Wang Y, Xiao W, Yao M. Systematic metabolic engineering enables highly efficient production of vitamin A in Saccharomyces cerevisiae. Synth Syst Biotechnol 2024; 10:58-67. [PMID: 39247801 PMCID: PMC11380465 DOI: 10.1016/j.synbio.2024.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 08/14/2024] [Accepted: 08/14/2024] [Indexed: 09/10/2024] Open
Abstract
Vitamin A is a micronutrient critical for versatile biological functions and has been widely used in the food, cosmetics, pharmaceutical, and nutraceutical industries. Synthetic biology and metabolic engineering enable microbes, especially the model organism Saccharomyces cerevisiae (generally recognised as safe) to possess great potential for the production of vitamin A. Herein, we first generated a vitamin A-producing strain by mining β-carotene 15,15'-mono(di)oxygenase from different sources and identified two isoenzymes Mbblh and Ssbco with comparable catalytic properties but different catalytic mechanisms. Combinational expression of isoenzymes increased the flux from β-carotene to vitamin A metabolism. To modulate the vitamin A components, retinol dehydrogenase 12 from Homo sapiens was introduced to achieve more than 90 % retinol purity using shake flask fermentation. Overexpressing POS5Δ17 enhanced the reduced nicotinamide adenine dinucleotide phosphate pool, and the titer of vitamin A was elevated by almost 46 %. Multi-copy integration of the key rate-limiting step gene Mbblh further improved the synthesis of vitamin A. Consequently, the titer of vitamin A in the strain harbouring the Ura3 marker was increased to 588 mg/L at the shake-flask level. Eventually, the highest reported titer of 5.21 g/L vitamin A in S. cerevisiae was achieved in a 1-L bioreactor. This study unlocked the potential of S. cerevisiae for synthesising vitamin A in a sustainable and economical way, laying the foundation for the commercial-scale production of bio-based vitamin A.
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Affiliation(s)
- Yi Shi
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Shuhuan Lu
- CABIO Bioengineering (Wuhan) Co., Ltd, Wuhan, 430075, China
| | - Xiao Zhou
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Xinhui Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Chenglong Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Nan Wu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Tianyu Dong
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Shilong Xing
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Ying Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Wenhai Xiao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
- School of Life Sciences, Faculty of Medicine, Tianjin University, China
- Georgia Tech Shenzhen Institute, Tianjin University, Shenzhen, 518071, China
| | - Mingdong Yao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
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Shin KC, Seo MJ, Kim YS, Yeom SJ. Molecular Properties of β-Carotene Oxygenases and Their Potential in Industrial Production of Vitamin A and Its Derivatives. Antioxidants (Basel) 2022; 11:1180. [PMID: 35740077 PMCID: PMC9227343 DOI: 10.3390/antiox11061180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/11/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
β-Carotene 15,15'-oxygenase (BCO1) and β-carotene 9',10'-oxygenase (BCO2) are potential producers of vitamin A derivatives, since they can catalyze the oxidative cleavage of dietary provitamin A carotenoids to retinoids and derivative such as apocarotenal. Retinoids are a class of chemical compounds that are vitamers of vitamin A or are chemically related to it, and are essential nutrients for humans and highly valuable in the food and cosmetics industries. β-carotene oxygenases (BCOs) from various organisms have been overexpressed in heterogeneous bacteria, such as Escherichia coli, and their biochemical properties have been studied. For the industrial production of retinal, there is a need for increased production of a retinal producer and biosynthesis of retinal using biocatalyst systems improved by enzyme engineering. The current review aims to discuss BCOs from animal, plants, and bacteria, and to elaborate on the recent progress in our understanding of their functions, biochemical properties, substrate specificity, and enzyme activities with respect to the production of retinoids in whole-cell conditions. Moreover, we specifically propose ways to integrate BCOs into retinal biosynthetic bacterial systems to improve the performance of retinal production.
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Affiliation(s)
- Kyung-Chul Shin
- Department of Integrative Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea;
| | - Min-Ju Seo
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea
| | - Yeong-Su Kim
- Wild Plants Industrialization Research Division, Baekdudaegan National Arboretum, Bonghwa 36209, Korea
| | - Soo-Jin Yeom
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea
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Chandra P, Enespa, Singh R, Arora PK. Microbial lipases and their industrial applications: a comprehensive review. Microb Cell Fact 2020; 19:169. [PMID: 32847584 PMCID: PMC7449042 DOI: 10.1186/s12934-020-01428-8] [Citation(s) in RCA: 265] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022] Open
Abstract
Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and microbiological. The uses of microbial lipase market is estimated to be USD 425.0 Million in 2018 and it is projected to reach USD 590.2 Million by 2023, growing at a CAGR of 6.8% from 2018. Microbial lipases (EC 3.1.1.3) catalyze the hydrolysis of long chain triglycerides. The microbial origins of lipase enzymes are logically dynamic and proficient also have an extensive range of industrial uses with the manufacturing of altered molecules. The unique lipase (triacylglycerol acyl hydrolase) enzymes catalyzed the hydrolysis, esterification and alcoholysis reactions. Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes. Immobilized enzymes depend on the immobilization technique and the carrier type. The choice of the carrier concerns usually the biocompatibility, chemical and thermal stability, and insolubility under reaction conditions, capability of easy rejuvenation and reusability, as well as cost proficiency. Bacillus spp., Achromobacter spp., Alcaligenes spp., Arthrobacter spp., Pseudomonos spp., of bacteria and Penicillium spp., Fusarium spp., Aspergillus spp., of fungi are screened large scale for lipase production. Lipases as multipurpose biological catalyst has given a favorable vision in meeting the needs for several industries such as biodiesel, foods and drinks, leather, textile, detergents, pharmaceuticals and medicals. This review represents a discussion on microbial sources of lipases, immobilization methods increased productivity at market profitability and reduce logistical liability on the environment and user.
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Affiliation(s)
- Prem Chandra
- Food Microbiology & Toxicology, Department of Microbiology, School for Biomedical and Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University (A Central) University, Lucknow, Uttar Pradesh 226025 India
| | - Enespa
- Department of Plant Pathology, School for Agriculture, SMPDC, University of Lucknow, Lucknow, 226007 U.P. India
| | - Ranjan Singh
- Department of Environmental Science, School for Environmental Science, Babasaheb Bhimrao Ambedkar University (A Central) University, Lucknow, U.P. India
| | - Pankaj Kumar Arora
- Department of Microbiology, School for Biomedical and Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University (A Central) University, Lucknow, U.P. India
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Abstract
Vitamin A and derivatives, the natural retinoids, underpin signaling pathways of cellular differentiation, and are key chromophores in vision. These functions depend on transfer across membranes, and carrier proteins to shuttle retinoids to specific cell compartments. Natural retinoids, ultimately derived from plant carotenoids by metabolism to all-trans retinol, are lipophilic and consist of a cyclohexenyl (β-ionone) moiety linked to a polyene chain. This structure constrains the orientation of retinoids within lipid membranes. Cis-trans isomerization at double bonds of the polyene chain and s-cis/s-trans rotational isomerization at single bonds define the functional dichotomy of retinoids (signaling/vision) and specificities of interactions with specific carrier proteins and receptors. Metabolism of all-trans retinol to 11-cis retinal, transfer to photoreceptors, and removal and recycling of all-trans retinal generated by photoreceptor irradiation, is the key process underlying vision. All-trans retinol transferred into cells is metabolized to all-trans retinoic acid and shuttled to the cell nucleus to regulate gene expression controlling organ, tissue and cell differentiation, and cellular homeostasis. Research methods need to address the potential of photoisomerization in vitro to confound research results, and data should be interpreted in the context of membrane-association properties of retinoids and physiological concentrations in vivo. Despite a century of research, there are many fundamental questions of retinoid cellular biochemistry and molecular biology still to be answered. Computational modeling techniques will have an important role for understanding the nuances of vitamin A signaling and function.
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Affiliation(s)
- Chris P F Redfern
- School of Natural & Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.
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Green AS, Fascetti AJ. Meeting the Vitamin A Requirement: The Efficacy and Importance of β-Carotene in Animal Species. ScientificWorldJournal 2016; 2016:7393620. [PMID: 27833936 PMCID: PMC5090096 DOI: 10.1155/2016/7393620] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/29/2016] [Indexed: 02/08/2023] Open
Abstract
Vitamin A is essential for life in all vertebrate animals. Vitamin A requirement can be met from dietary preformed vitamin A or provitamin A carotenoids, the most important of which is β-carotene. The metabolism of β-carotene, including its intestinal absorption, accumulation in tissues, and conversion to vitamin A, varies widely across animal species and determines the role that β-carotene plays in meeting vitamin A requirement. This review begins with a brief discussion of vitamin A, with an emphasis on species differences in metabolism. A more detailed discussion of β-carotene follows, with a focus on factors impacting bioavailability and its conversion to vitamin A. Finally, the literature on how animals utilize β-carotene is reviewed individually for several species and classes of animals. We conclude that β-carotene conversion to vitamin A is variable and dependent on a number of factors, which are important to consider in the formulation and assessment of diets. Omnivores and herbivores are more efficient at converting β-carotene to vitamin A than carnivores. Absorption and accumulation of β-carotene in tissues vary with species and are poorly understood. More comparative and mechanistic studies are required in this area to improve the understanding of β-carotene metabolism.
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Affiliation(s)
- Alice S. Green
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Andrea J. Fascetti
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Hong SH, Kim KR, Oh DK. Biochemical properties of retinoid-converting enzymes and biotechnological production of retinoids. Appl Microbiol Biotechnol 2015; 99:7813-26. [DOI: 10.1007/s00253-015-6830-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/06/2015] [Accepted: 07/08/2015] [Indexed: 10/23/2022]
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Zhang R, Wang Y, Li R, Chen G. Transcriptional Factors Mediating Retinoic Acid Signals in the Control of Energy Metabolism. Int J Mol Sci 2015; 16:14210-44. [PMID: 26110391 PMCID: PMC4490549 DOI: 10.3390/ijms160614210] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 02/07/2023] Open
Abstract
Retinoic acid (RA), an active metabolite of vitamin A (VA), is important for many physiological processes including energy metabolism. This is mainly achieved through RA-regulated gene expression in metabolically active cells. RA regulates gene expression mainly through the activation of two subfamilies in the nuclear receptor superfamily, retinoic acid receptors (RARs) and retinoid X receptors (RXRs). RAR/RXR heterodimers or RXR/RXR homodimers bind to RA response element in the promoters of RA target genes and regulate their expressions upon ligand binding. The development of metabolic diseases such as obesity and type 2 diabetes is often associated with profound changes in the expressions of genes involved in glucose and lipid metabolism in metabolically active cells. RA regulates some of these gene expressions. Recently, in vivo and in vitro studies have demonstrated that status and metabolism of VA regulate macronutrient metabolism. Some studies have shown that, in addition to RARs and RXRs, hepatocyte nuclear factor 4α, chicken ovalbumin upstream promoter-transcription factor II, and peroxisome proliferator activated receptor β/δ may function as transcriptional factors mediating RA response. Herein, we summarize current progresses regarding the VA metabolism and the role of nuclear receptors in mediating RA signals, with an emphasis on their implication in energy metabolism.
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Affiliation(s)
- Rui Zhang
- State Food and Drug Administration Hubei Center for Medical Equipment Quality Supervision and Testing, 666 High-Tech Avenue, Wuhan 430000, China.
| | - Yueqiao Wang
- Department of Nutrition and Food Hygiene, Wuhan University, 185 East Lake Road, Wuhan 430071, China.
| | - Rui Li
- Department of Nutrition and Food Hygiene, Wuhan University, 185 East Lake Road, Wuhan 430071, China.
| | - Guoxun Chen
- Department of Nutrition, University of Tennessee at Knoxville, 1215 West Cumberland Avenue, Knoxville, TN 37996, USA.
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9
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Sui X, Kiser PD, von Lintig J, Palczewski K. Structural basis of carotenoid cleavage: from bacteria to mammals. Arch Biochem Biophys 2013; 539:203-13. [PMID: 23827316 PMCID: PMC3818509 DOI: 10.1016/j.abb.2013.06.012] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 10/26/2022]
Abstract
Carotenoids and their metabolic derivatives serve critical functions in both prokaryotic and eukaryotic cells, including pigmentation, photoprotection and photosynthesis as well as cell signaling. These organic compounds are also important for visual function in vertebrate and non-vertebrate organisms. Enzymatic transformations of carotenoids to various apocarotenoid products are catalyzed by a family of evolutionarily conserved, non-heme iron-containing enzymes named carotenoid cleavage oxygenases (CCOs). Studies have revealed that CCOs are critically involved in carotenoid homeostasis and essential for the health of organisms including humans. These enzymes typically display a high degree of regio- and stereo-selectivity, acting on specific positions of the polyene backbone located in their substrates. By oxidatively cleaving and/or isomerizing specific double bonds, CCOs generate a variety of apocarotenoid isomer products. Recent structural studies have helped illuminate the mechanisms by which CCOs mobilize their lipophilic substrates from biological membranes to perform their characteristic double bond cleavage and/or isomerization reactions. In this review, we aim to integrate structural and biochemical information about CCOs to provide insights into their catalytic mechanisms.
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Affiliation(s)
- Xuewu Sui
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 2109 Adelbert Rd, Cleveland, OH 44106-4965, USA
| | - Philip D. Kiser
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 2109 Adelbert Rd, Cleveland, OH 44106-4965, USA
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 2109 Adelbert Rd, Cleveland, OH 44106-4965, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 2109 Adelbert Rd, Cleveland, OH 44106-4965, USA
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dela Seña C, Narayanasamy S, Riedl KM, Curley RW, Schwartz SJ, Harrison EH. Substrate specificity of purified recombinant human β-carotene 15,15'-oxygenase (BCO1). J Biol Chem 2013; 288:37094-103. [PMID: 24187135 DOI: 10.1074/jbc.m113.507160] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Humans cannot synthesize vitamin A and thus must obtain it from their diet. β-Carotene 15,15'-oxygenase (BCO1) catalyzes the oxidative cleavage of provitamin A carotenoids at the central 15-15' double bond to yield retinal (vitamin A). In this work, we quantitatively describe the substrate specificity of purified recombinant human BCO1 in terms of catalytic efficiency values (kcat/Km). The full-length open reading frame of human BCO1 was cloned into the pET-28b expression vector with a C-terminal polyhistidine tag, and the protein was expressed in the Escherichia coli strain BL21-Gold(DE3). The enzyme was purified using cobalt ion affinity chromatography. The purified enzyme preparation catalyzed the oxidative cleavage of β-carotene with a Vmax = 197.2 nmol retinal/mg BCO1 × h, Km = 17.2 μM and catalytic efficiency kcat/Km = 6098 M(-1) min(-1). The enzyme also catalyzed the oxidative cleavage of α-carotene, β-cryptoxanthin, and β-apo-8'-carotenal to yield retinal. The catalytic efficiency values of these substrates are lower than that of β-carotene. Surprisingly, BCO1 catalyzed the oxidative cleavage of lycopene to yield acycloretinal with a catalytic efficiency similar to that of β-carotene. The shorter β-apocarotenals (β-apo-10'-carotenal, β-apo-12'-carotenal, β-apo-14'-carotenal) do not show Michaelis-Menten behavior under the conditions tested. We did not detect any activity with lutein, zeaxanthin, and 9-cis-β-carotene. Our results show that BCO1 favors full-length provitamin A carotenoids as substrates, with the notable exception of lycopene. Lycopene has previously been reported to be unreactive with BCO1, and our findings warrant a fresh look at acycloretinal and its alcohol and acid forms as metabolites of lycopene in future studies.
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Eroglu A, Harrison EH. Carotenoid metabolism in mammals, including man: formation, occurrence, and function of apocarotenoids. J Lipid Res 2013; 54:1719-30. [PMID: 23667178 PMCID: PMC3679377 DOI: 10.1194/jlr.r039537] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Indexed: 12/22/2022] Open
Abstract
Vitamin A was recognized as an essential nutrient 100 years ago. In the 1930s, it became clear that dietary β-carotene was cleaved at its central double to yield vitamin A (retinal or β-apo-15'-carotenal). Thus a great deal of research has focused on the central cleavage of provitamin A carotenoids to form vitamin A (retinoids). The mechanisms of formation and the physiological role(s) of noncentral (eccentric) cleavage of both provitamin A carotenoids and nonprovitamin A carotenoids has been less clear. It is becoming apparent that the apocarotenoids exert unique biological activities themselves. These compounds are found in the diet and thus may be absorbed in the intestine, or they may form from enzymatic or nonenzymatic cleavage of the parent carotenoids. The mechanism of action of apocarotenoids in mammals is not fully worked out. However, as detailed in this review, they have profound effects on gene expression and work, at least in part, through the modulation of ligand-activated nuclear receptors. Understanding the interactions of apocarotenoids with other lipid-binding proteins, chaperones, and metabolizing enzymes will undoubtedly increase our understanding of the biological roles of these carotenoid metabolites.
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Affiliation(s)
| | - Earl H. Harrison
- Department of Human Nutrition, Ohio State University, Columbus, OH
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Harrison EH. Mechanisms involved in the intestinal absorption of dietary vitamin A and provitamin A carotenoids. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1821:70-7. [PMID: 21718801 PMCID: PMC3525326 DOI: 10.1016/j.bbalip.2011.06.002] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 04/29/2011] [Accepted: 06/01/2011] [Indexed: 01/15/2023]
Abstract
Vitamin A is an essential nutrient for humans and is converted to the visual chromophore, 11-cis-retinal, and to the hormone, retinoic acid. Vitamin A in animal-derived foods is found as long chain acyl esters of retinol and these are digested to free fatty acids and retinol before uptake by the intestinal mucosal cell. The retinol is then reesterified to retinyl esters for incorporation into chlylomicrons and absorbed via the lymphatics or effluxed into the portal circulation facilitated by the lipid transporter, ABCA1. Provitamin A carotenoids such as β-carotene are found in plant-derived foods. These and other carotenoids are transported into the mucosal cell by scavenger receptor class B type I (SR-BI). Provitamin A carotenoids are partly converted to retinol by oxygenase and reductase enzymes and the retinol so produced is available for absorption via the two pathways described above. The efficiency of vitamin A and carotenoid intestinal absorption is determined by the regulation of a number of proteins involved in the process. Polymorphisms in genes for these proteins lead to individual variability in the metabolism and transport of vitamin A and carotenoids. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.
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Affiliation(s)
- Earl H Harrison
- Department of Human Nutrition, The Ohio State University, 350 Campell Hall, 1787 Neil Avenue, Columbus, OH 43210, USA.
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Lietz G, Lange J, Rimbach G. Molecular and dietary regulation of β,β-carotene 15,15′-monooxygenase 1 (BCMO1). Arch Biochem Biophys 2010; 502:8-16. [DOI: 10.1016/j.abb.2010.06.032] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/25/2010] [Accepted: 06/28/2010] [Indexed: 11/28/2022]
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Kim YS, Oh DK. Biotransformation of carotenoids to retinal by carotenoid 15,15'-oxygenase. Appl Microbiol Biotechnol 2010; 88:807-16. [PMID: 20717662 DOI: 10.1007/s00253-010-2823-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/03/2010] [Accepted: 08/03/2010] [Indexed: 12/01/2022]
Abstract
Retinal, a precursor of vitamin A, has been used in foods, cosmetics, pharmaceuticals, nutraceuticals, and animal feed additives. Carotenoid 15,15'-oxygenases, including β-carotene 15,15'-oxygenases from mammalians, chickens, fruit flies, zebrafishes, the uncultured marine bacterium, and the fungus Fusarium fujikuroi, and apo-carotenoid 15,15'-oxygenases from cyanobacteria produce retinal from carotenoids. In this article, the biochemical properties, reaction mechanism, and substrate specificity of carotenoid oxygenases are reviewed, along with a description of the enzymatic biotransformation of carotenoids to retinal. Retinal producing methods using metabolically engineered cells and uncharacterized proteins are suggested.
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Affiliation(s)
- Yeong-Su Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea
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Poliakov E, Gentleman S, Chander P, Cunningham FX, Grigorenko BL, Nemuhin AV, Redmond TM. Biochemical evidence for the tyrosine involvement in cationic intermediate stabilization in mouse beta-carotene 15, 15'-monooxygenase. BMC BIOCHEMISTRY 2009; 10:31. [PMID: 20003456 PMCID: PMC2801523 DOI: 10.1186/1471-2091-10-31] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 12/14/2009] [Indexed: 11/10/2022]
Abstract
Background β-carotene 15,15'-monooxygenase (BCMO1) catalyzes the crucial first step in vitamin A biosynthesis in animals. We wished to explore the possibility that a carbocation intermediate is formed during the cleavage reaction of BCMO1, as is seen for many isoprenoid biosynthesis enzymes, and to determine which residues in the substrate binding cleft are necessary for catalytic and substrate binding activity. To test this hypothesis, we replaced substrate cleft aromatic and acidic residues by site-directed mutagenesis. Enzymatic activity was measured in vitro using His-tag purified proteins and in vivo in a β-carotene-accumulating E. coli system. Results Our assays show that mutation of either Y235 or Y326 to leucine (no cation-π stabilization) significantly impairs the catalytic activity of the enzyme. Moreover, mutation of Y326 to glutamine (predicted to destabilize a putative carbocation) almost eliminates activity (9.3% of wt activity). However, replacement of these same tyrosines with phenylalanine or tryptophan does not significantly impair activity, indicating that aromaticity at these residues is crucial. Mutations of two other aromatic residues in the binding cleft of BCMO1, F51 and W454, to either another aromatic residue or to leucine do not influence the catalytic activity of the enzyme. Our ab initio model of BCMO1 with β-carotene mounted supports a mechanism involving cation-π stabilization by Y235 and Y326. Conclusions Our data are consistent with the formation of a substrate carbocation intermediate and cation-π stabilization of this intermediate by two aromatic residues in the substrate-binding cleft of BCMO1.
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Kim YS, Kim NH, Kim HJ, Lee JK, Kim SW, Oh DK. Effective production of retinal from β-carotene using recombinant mouse β-carotene 15,15′-monooxygenase. Appl Microbiol Biotechnol 2007; 76:1339-45. [PMID: 17687551 DOI: 10.1007/s00253-007-1118-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/07/2007] [Accepted: 07/09/2007] [Indexed: 11/26/2022]
Abstract
The gene encoding beta-carotene 15,15'-monooxygenase from Mus musculus (house mouse), which cleaves beta-carotene into two molecules of retinal, was cloned and expressed in Escherichia coli. The expressed enzyme was purified by His-tag affinity and resource Q ion exchange chromatography columns to a final specific activity of 0.51 U mg(-1). The optimum pH, temperature, substrate and detergent concentrations, and enzyme amount for effective retinal production were determined to be 9.0, 37 degrees C, 200 mg l(-1) beta-carotene, 5% (w/v) Tween 40, and 0.2 U ml(-1) enzyme, respectively. Under optimum conditions, the recombinant enzyme produced 72 mg l(-1) retinal in a 15-h reaction time, with a conversion yield of 36% (w/w). The specific activity of the purified enzyme and retinal production obtained in the present study were the highest results ever reported.
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Affiliation(s)
- Yeong-Su Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, South Korea
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17
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Braaz R, Armbruster W, Jendrossek D. Heme-dependent rubber oxygenase RoxA of Xanthomonas sp. cleaves the carbon backbone of poly(cis-1,4-Isoprene) by a dioxygenase mechanism. Appl Environ Microbiol 2005; 71:2473-8. [PMID: 15870336 PMCID: PMC1087590 DOI: 10.1128/aem.71.5.2473-2478.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oxidative cleavage of poly(cis-1,4-isoprene) by rubber oxygenase RoxA purified from Xanthomonas sp. was investigated in the presence of different combinations of (16)O(2), (18)O(2), H(2)(16)O, and H(2)(18)O. 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al (ODTD; m/z 236) was the main cleavage product in the absence of (18)O-compounds. Incorporation of one (18)O atom in ODTD was found if the cleavage reaction was performed in the presence of (18)O(2) and H(2)(16)O. Incubation of poly(cis-1,4-isoprene) (with RoxA) or of isolated unlabeled ODTD (without RoxA) with H(2)(18)O in the presence of (16)O(2) indicated that the carbonyl oxygen atoms of ODTD significantly exchanged with oxygen atoms derived from water. The isotope exchange was avoided by simultaneous enzymatic reduction of both carbonyl functions of ODTD to the corresponding dialcohol (12-hydroxy-4,8-dimethyl-trideca-4,8-diene-1-ol (HDTD; m/z 240) during RoxA-mediated in vitro cleavage of poly(cis-1,4-isoprene). In the presence of (18)O(2), H(2)(16)O, and alcohol dehydrogenase/NADH, incorporation of two atoms of (18)O into the reduced metabolite HDTD was found (m/z 244), revealing that RoxA cleaves rubber by a dioxygenase mechanism. Based on the labeling results and the presence of two hemes in RoxA, a model of the enzymatic cleavage mechanism of poly(cis-1,4-isoprene) is proposed.
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Affiliation(s)
- Reinhard Braaz
- Institut für Mikrobiologie, Universität Stuttgart, Allmandring 31, 70550 Stuttgart, Germany
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18
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Poliakov E, Gentleman S, Cunningham FX, Miller-Ihli NJ, Redmond TM. Key role of conserved histidines in recombinant mouse beta-carotene 15,15'-monooxygenase-1 activity. J Biol Chem 2005; 280:29217-23. [PMID: 15951442 DOI: 10.1074/jbc.m500409200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alignment of sequences of vertebrate beta-carotene 15,15'-monooxygenase-1 (BCMO1) and related oxygenases revealed four perfectly conserved histidines and five acidic residues (His172, His237, His308, His514, Asp52, Glu140, Glu314, Glu405, and Glu457 in mouse BCMO1). Because BCMO1 activity is iron-dependent, we propose that these residues participate in iron coordination and therefore are essential for catalytic activity. To test this hypothesis, we produced mutant forms of mouse BCMO1 by replacing the conserved histidines and acidic residues as well as four histidines and one glutamate non-conserved in the overall family with alanines by site-directed mutagenesis. Our in vitro and in vivo data showed that mutation of any of the four conserved histidines and Glu405 caused total loss of activity. However, mutations of non-conserved histidines or any of the other conserved acidic residues produced impaired although enzymatically active proteins, with a decrease in activity mostly due to changes in V(max). The iron bound to protein was determined by inductively coupled plasma atomic emission spectrometry. Bound iron was much lower in preparations of inactive mutants than in the wild-type protein. Therefore, the conserved histidines and Glu405 are absolutely required for the catalytic mechanism of BCMO1. Because the mutant proteins are impaired in iron binding, these residues are concluded to coordinate iron required for catalytic activity. These data are discussed in the context of the predicted structure for the related eubacterial apocarotenal oxygenase.
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Affiliation(s)
- Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, Bethesda, MD 20892-0706, USA
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19
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During A, Harrison EH. Intestinal absorption and metabolism of carotenoids: insights from cell culture. Arch Biochem Biophys 2004; 430:77-88. [PMID: 15325914 DOI: 10.1016/j.abb.2004.03.024] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Revised: 03/11/2004] [Indexed: 11/30/2022]
Abstract
Cell culture models are useful for studying intestinal absorption and metabolism of carotenoids. The human intestinal cell line, Caco-2, has been the most widely used model for these studies. The PF11 and TC7 clones of Caco-2 exhibit beta-carotene-15,15'-oxygenase activity, a key enzyme in the conversion of carotenoids to vitamin A. Studies on the recent cloning of this enzyme are discussed. An in vitro cell culture system used to study intestinal absorption of carotenoids is presented. Under conditions mimicking the postprandial state, Caco-2 cells on membranes take up carotenoids and secrete them incorporated into chylomicrons. Both the cellular uptake and secretion of beta-carotene are saturable, concentration-dependent processes. The selective absorption of all-trans beta-carotene versus its cis isomers, the differential absorption of individual carotenoids, and the specific interactions between carotenoids during their absorption are discussed. The participation of a specific epithelial transporter in the intestinal absorption of carotenoids is proposed.
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Affiliation(s)
- Alexandrine During
- Phytonutrients Laboratory, Beltsville Human Nutrition Research Center, U.S. Department of Agriculture, Beltsville, MD 20705, USA.
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20
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Lindqvist A, Andersson S. Cell type-specific expression of beta-carotene 15,15'-mono-oxygenase in human tissues. J Histochem Cytochem 2004; 52:491-9. [PMID: 15034000 DOI: 10.1177/002215540405200407] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We studied the cell type-specific expression of human beta-carotene 15,15'-mono-oxygenase (BCO1), an enzyme that catalyzes the first step in the conversion of dietary provitamin A carotenoids to vitamin A. Immunohistochemical analysis using two monoclonal antibodies against different epitopes of the protein revealed that BCO1 is expressed in epithelial cells in a variety of human tissues, including mucosa and glandular cells of stomach, small intestine, and colon, parenchymal cells in liver, cells that make up the exocrine glands in pancreas, glandular cells in prostate, endometrium, and mammary tissue, kidney tubules, and in keratinocytes of the squamous epithelium of skin. Furthermore, BCO1 is detected in steroidogenic cells in testis, ovary, and adrenal gland, as well as skeletal muscle cells. Epithelia in general are structures that are very sensitive to vitamin A deficiency, and although the extraintestinal function of BCO1 is unclear, the finding that the enzyme is expressed in all epithelia examined thus far leads us to suggest that BCO1 may be important for local synthesis of vitamin A, constituting a back-up pathway of vitamin A synthesis during times of insufficient dietary intake of vitamin A.
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Affiliation(s)
- Annika Lindqvist
- Department of Obstetrics-Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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21
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Russell RM. The enigma of beta-carotene in carcinogenesis: what can be learned from animal studies. J Nutr 2004; 134:262S-268S. [PMID: 14704331 DOI: 10.1093/jn/134.1.262s] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Beta-carotene and other carotenoids have been thought to have anti-cancer activity, either because of antioxidant activity or because of their ability to be converted to vitamin A. Nevertheless, two large scale intervention studies in humans using high doses of beta-carotene found that beta-carotene supplementation resulted in more lung cancer rather than less lung cancer among smoking and asbestos exposed populations. Studies conducted in the ferret have elucidated molecular mechanisms behind this observation, in that high-dose beta-carotene and smoke exposure in these animals leads to squamous metaplasia, a pre-cancerous lesion in the lung. High dose beta-carotene in the smoke exposed animals was found to give rise to a number of transient oxidative metabolites, which include P450 enzymes that result in the destruction of retinoic acid, and diminished retinoid signaling, and enhanced cell proliferation. In addition, eccentric cleavage beta-carotene metabolites facilitate the binding of smoke derived carcinogens to DNA. In other ferret studies low dose beta-carotene smoke exposure provided mild protection against squamous metaplasia. Thus, it appears that the explanation of the apparent paradoxical effects of beta-carotene on lung cancer is related to dose. The metabolism and breakdown of natural products should be thoroughly investigated in animal models before embarking on large scale intervention trials, particularly when using unusually high doses that greatly exceed normal dietary levels.
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Affiliation(s)
- Robert M Russell
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
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22
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Abstract
In vertebrates, provitamin A carotenoids are converted to retinal by beta-carotene-15,15'-dioxygenase. The enzyme activity is expressed specifically in intestinal epithelium and in liver. The intestinal enzyme not only plays an important role in providing animals with vitamin A, but also determines whether provitamin A carotenoids are converted to vitamin A or circulated in the body as intact carotenoids. We have found that a high fat diet enhanced the beta-carotene dioxygenase activity together with the cellular retinol binding protein type II level in rat intestines. Flavonols with a catechol structure in the B-ring and 2,6-di-tert-butyl-4-methylphenol inhibited the dioxygenase activity of pig intestinal homogenates and the conversion of beta-carotene to retinol in Caco-2 human intestinal cells. Thus, the bioavailability of dietary provitamin A carotenoids might be modulated by the other food components ingested. Regulation of the dioxygenase activity and its relation to the retinoid metabolism as well as to lipid metabolism deserve further study. In contrast to enzymatic cleavage, it is known that both retinal and beta-apocarotenals are formed in vitro from beta-carotene by chemical transformation, which cleaves conjugated double bonds at random positions under various oxidative conditions. Moreover, recent studies have indicated that the oxidation products formed by chemical transformation might have specific actions on the proliferation of certain cancer cells. We have found that lycopene, a typical nonprovitamin A carotenoid, was cleaved in vitro to acycloretinal, acycloretinoic acid and apolycopenals in a nonenzymatic manner, and that the mixture of oxidation products of lycopene induced apoptosis of HL-60 human promyelocytic leukemia cells. Thus, it is worth evaluating the formation of oxidation products and their biological actions, in order to elucidate the underlying mechanisms of the beneficial effects of carotenoids on human health.
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Affiliation(s)
- Akihiko Nagao
- National Food Research Institute, Tsukuba, Ibaraki 305-8642, Japan.
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23
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Abstract
Beta,beta-carotene 15,15'-monooxygensae (betaCMOOX) is the key enzyme involved in the metabolism of provitamin A carotenoids to retinal. Although the enzyme has been known for >40 y, it has been only within the last 2 y that the cloning and the molecular characterization of the betaCMOOX from several species was reported in literature. New clones of the carotene metabolizing enzyme have emerged, all belonging to the family of double bond cleavage enzymes, suggesting common ancestry. BetaCMOOX cleaves beta,beta-carotene to retinal in an in vitro activity assay; no apo-carotenals were identified. The second enzyme involved in carotenoid metabolism, beta,beta-carotene 9',10'-dioxygenase, is responsible for the excentric cleavage pathway of carotenoids, cleaving beta,beta-carotene to 10'-apo-carotenal and beta-ionone. In an expression overview, the betaCMOOX was detected in duodenum, liver, kidney and in the lungs of chickens. In mice, the mRNA for the central cleavage enzyme was highly expressed in liver, testes, small intestine, and kidney. betaCMOOX expression was highest in epithelial and endothelial structures in both species. These results suggest that the source of vitamin A originates from carotenoids in the corresponding tissues, in addition to retinol supplied from liver stores.
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Affiliation(s)
- Adrian Wyss
- DSM Nutritional Products, Human Nutrition and Health, PO Box 3255, CH-4002 Basel, Switzerland.
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24
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Abstract
In early 1900s, based on indirect evidence, Steenbock and Morton independently predicted that beta-carotene could be the biological precursor of vitamin A, although this notion was contested by others. In the 1930s, Thomas Moore showed the in vivo formation of vitamin A from beta-carotene. But it was not until Jim Olson and DeWitt Goodman independently showed in 1965 the formation of retinal, the aldehyde form of vitamin A from beta-carotene in cell-free extracts of liver and intestine, that this vital pathway of beta-carotene was recognized. Despite compelling evidence in several experimental systems for the central cleavage of beta-carotene to retinal by many investigators, there were some careful independent studies by Glover et al., Ganguly et al., Hansen and Meret and Krinsky et al. showing the eccentric cleavage of beta-carotene resulting in the formation of apocarotenoids both in vivo and in vitro. In an attempt to resolve this controversial issue, we revisited this problem in 1989 and showed beyond doubt the formation of retinal as the sole enzymatic product of a cytosolic enzyme from rabbit and rat intestinal mucosa by mass spectrometry and tracer analysis of the crystallized product. This was confirmed in 1996 by Nagao using the pig intestinal extract. Yeum et al. confirmed in 2000 that retinal is the sole product of beta-carotene cleavage in the presence of alpha-tocopherol, and that the observed formation of apocarotenoids occurs only in the absence of an antioxidant like alpha-tocopherol. In the same year, Barua and Olson also concluded from their in vivo studies in rats that central cleavage is by far the major pathway for the formation of vitamin A from beta-carotene. Beta, beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) is the key enzyme that cleaves beta-carotene into two molecules of retinal. It is a cytosolic enzyme primarily localized in the duodenal mucosa although it has been found in liver. It is a 66 kDa sulfhydryl protein, requires molecular oxygen and is activated by ferrous ions. It is highly specific for 15:15' ethylenic bond of carotenoids although it has fairly broad specificity towards a number of carotenoids with at least one intact beta-ionone ring. The dioxygenase was recently cloned from Drosophila melanogaster and from the chicken intestine. The recombinant protein was found to form retinal as the sole cleavage product of beta-carotene. No apo-carotenoids were formed. Therefore, it is unequivocally proven that the major, if not the sole, pathway of beta-carotene cleavage to vitamin A is by oxidative cleavage of the central ethylenic bond of beta-carotene to yield two molecules of retinal. Most recently, human dioxygenase has also been cloned. Thus, the wisdom, vision and epoch-making mission of Jim Olson in the science of beta-carotene metabolism have been accomplished. I have no doubt that the impact of his original discovery of the dioxygenase and its importance in vitamin A nutriture should be forthcoming in the near future.
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Affiliation(s)
- M R Lakshman
- Lipid Research Laboratory, VA Medical Center and the George Washington University, Washington, DC, USA.
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25
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Bachmann H, Desbarats A, Pattison P, Sedgewick M, Riss G, Wyss A, Cardinault N, Duszka C, Goralczyk R, Grolier P. Feedback regulation of beta,beta-carotene 15,15'-monooxygenase by retinoic acid in rats and chickens. J Nutr 2002; 132:3616-22. [PMID: 12468597 DOI: 10.1093/jn/132.12.3616] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
beta,beta-Carotene 15,15'-monooxygenase (formerly termed beta,beta-carotene 15,15'-dioxygenase, EC 1.13.11.21) catalyzes the conversion of provitamin A carotenoids to retinal in vertebrate tissues. In the present study, we investigated whether preformed vitamin A or beta-carotene and its direct metabolites can regulate the enzyme activity in vivo. We found dose-dependent decreases in intestinal beta,beta-carotene monooxygenase activity after oral administration to rats of retinyl acetate (up to -79%), beta-carotene (up to -79%), apo-8'-carotenal (up to -56%), all-trans retinoic acid (up to -88%), and 9-cis retinoic acid (up to -67%). Liver beta,beta-carotene 15,15'-monooxygenase (betaCMOOX) activity was not affected. Apo-12'carotenal and the retinoic acid receptor (RAR) alpha antagonist Ro 41-5253 significantly increased the intestinal enzyme activity by 55 and 94%, respectively. When beta-carotene was administered to rats pretreated with the two cytochrome P(450) (CYP) inducers, pentobarbital and naphthoflavone, the intestinal betaCMOOX activity increased by 39%. In a transcriptional study in chickens, treatment with retinoic acid resulted in low expression of the intestinal betaCMOOX. Our data suggest that retinoids and carotenoids might regulate betaCMOOX expression by a transcriptional feedback mechanism via interaction with members of the RAR family.
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Affiliation(s)
- Heinrich Bachmann
- Roche Vitamins, Human Nutrition and Health, Carotenoid Group, CH-4070 Basel, Switzerland
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26
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Abstract
The possible role of carotenoids and their metabolites in disease prevention is far from fully understood, because the bioavailabilities of carotenoids are complicated by multiple factors that affect their absorption, breakdown, transport, and storage. Rapid progress in developing sophisticated methodologies, including use of stable-isotope dilution methods, now allows for an accurate determination of the true vitamin A activity of provitamin A carotenoids. The recent identification of specific enzymes, which catalyze the breakdown of beta-carotene as well as nonprovitamin A carotenoids, is providing a better understanding of the functions of carotenoids at the molecular level. The pathways and possible mechanisms of carotenoid breakdown and factors affecting the bioavailability of carotenoids, such as carotenoid type, food matrix, interaction with other carotenoids and other food components, nutritional status, aging, and infection, are discussed in this review.
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Affiliation(s)
- Kyung-Jin Yeum
- Jean Mayer USDA-Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA
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27
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Fleischmann P, Studer K, Winterhalter P. Partial purification and kinetic characterization of a carotenoid cleavage enzyme from quince fruit (Cydonia oblonga). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:1677-1680. [PMID: 11879057 DOI: 10.1021/jf011184j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
For the first time, a cytosolic carotenoid cleavage enzyme isolated from quince (Cydonia oblonga) fruit is described. The enzyme was partially purified by using centrifugation, acetone precipitation, ultrafiltration (300 kD, 50 kD), isoelectric focusing (pH 3-10), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%). In this way, an enzymatically active protein fraction was obtained that contained three similar proteins, all exhibiting molecular weights in the range of 20 kD. Using beta-carotene as substrate, the enzyme activity was detected spectrophotometrically at a wavelength of 505 nm. The time constant of the reaction was 8.2 min, the Michaelis constant (K(m)) was 11.0 micromol x L(-1), and the maximum velocity (v(max)) was 0.083 micromol x L(-1) x min(-1) x mg(protein)(-1). The optimum temperature was above 50 degrees C.
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Affiliation(s)
- Peter Fleischmann
- Institute of Food Chemistry, TU Braunschweig, Schleinitzstrasse 20, DE 38106 Braunschweig, Germany.
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28
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During A, Smith MK, Piper JB, Smith JC. beta-Carotene 15,15'-Dioxygenase activity in human tissues and cells: evidence of an iron dependency. J Nutr Biochem 2001; 12:640-647. [PMID: 12031257 DOI: 10.1016/s0955-2863(01)00184-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The two objectives of this study were to investigate beta-carotene 15,15'-dioxygenase activity in human tissues and to determine the effect of desferrioxamine on the dioxygenase activity. Two human in vitro models were used: the TC7 clone of the intestinal cell line Caco-2 and small intestinal mucosa preparations. beta-Carotene 15,15'-dioxygenase activity in the small intestinal mucosa was (mean +/- SD) 97.4 +/- 39.8 pmol/h.mg protein for five adults (44-89 y) and 20 pmol/h.mg for an infant (17 months). No activity was detected in adult stomach tissue. We report for the first time the dioxygenase activity in human liver: 62 pmol/h.mg for a normal adult liver and 7 pmol/h.mg for a liver exhibiting gross pathology. The maximum capacity of beta-carotene cleavage in an adult was estimated to be 12 mg/day (one fifth by small intestine and four fifths by liver), assuming an optimal beta-carotene/retinal cleavage ratio of 1:2. The dioxygenase activity was decreased up to 80% with increasing desferrioxamine concentrations in the two in vitro models. Desferrioxamine was characterized as a noncompetitive inhibitor. In TC7 cells, the inhibitory effect of desferrioxamine was reversed by iron addition, suggesting that this effect was related to the ability of desferrioxamine to chelate iron, purported to be an obligate cofactor of the enzyme. In conclusion, these data report the presence of beta-carotene 15,15'-dioxygenase activity in human small intestine and liver and demonstrate that desferrioxamine efficiently inhibits intestinal beta-carotene cleavage in human tissues and cells.
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Affiliation(s)
- Alexandrine During
- USDA-ARS, Beltsville Human Nutrition Research Center, Phytonutrients Laboratory, 20705, Beltsville, Maryland, USA
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29
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Leuenberger MG, Engeloch-Jarret C, Woggon WD. The Reaction Mechanism of the Enzyme-Catalyzed Central Cleavage of β-Carotene to Retinal. Angew Chem Int Ed Engl 2001; 40:2613-2617. [PMID: 29712336 DOI: 10.1002/1521-3773(20010716)40:14<2613::aid-anie2613>3.0.co;2-z] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2001] [Indexed: 11/10/2022]
Abstract
Seeing things as they really are: The enzyme catalyzing the central cleavage of β-carotene (1) to retinal (2) is not, as previously thought, a dioxygenase. Incubation of the substrate analogue α-carotene in the presence of highly enriched 17 O2 and H218 O revealed a monooxygenase mechanism.
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Affiliation(s)
- Michele G Leuenberger
- Institute of Organic Chemistry University of Basel St. Johanns-Ring 19, 4056 Basel (Switzerland) Fax: (+41) 61-267-1102
| | - Caroline Engeloch-Jarret
- Institute of Organic Chemistry University of Basel St. Johanns-Ring 19, 4056 Basel (Switzerland) Fax: (+41) 61-267-1102
| | - Wolf-D Woggon
- Institute of Organic Chemistry University of Basel St. Johanns-Ring 19, 4056 Basel (Switzerland) Fax: (+41) 61-267-1102
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30
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Leuenberger MG, Engeloch-Jarret C, Woggon WD. The Reaction Mechanism of the Enzyme-Catalyzed Central Cleavage ofβ-Carotene to Retinal. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010716)113:14<2683::aid-ange2683>3.0.co;2-n] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Wyss A, Wirtz GM, Woggon WD, Brugger R, Wyss M, Friedlein A, Riss G, Bachmann H, Hunziker W. Expression pattern and localization of beta,beta-carotene 15,15'-dioxygenase in different tissues. Biochem J 2001; 354:521-9. [PMID: 11237856 PMCID: PMC1221683 DOI: 10.1042/0264-6021:3540521] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Beta,beta-carotene 15,15'-dioxygenase cleaves beta,beta-carotene into two molecules of retinal, and is the key enzyme in the metabolism of beta,beta-carotene to vitamin A. The enzyme has been known for more than 40 years, yet all attempts to purify the protein to homogeneity have failed. Recently, the successful cloning and sequencing of an enzyme with beta,beta-carotene 15,15'-dioxygenase activity from chicken, as well as from Drosophila, has been reported. Here, we describe in detail our attempt to enrich the chicken beta,beta-carotene 15,15'-dioxygenase to such an extent as to allow determination of partial amino acid sequences, which were then used to design degenerate oligonucleotides. Screening of a chicken duodenal expression library yielded a full-length clone containing a coding sequence of 1578 bp. Functional expression in Escherichia coli and in eukaryotic cell lines confirmed that we had cloned the first vertebrate dioxygenase that cleaves beta,beta-carotene at the central 15,15'-double bond. By performing a sequence homology search, the cDNA sequence of the mouse homologue was found as an expressed sequence tag (EST) in the gene bank. At the amino-acid level, the degree of homology between the chicken and mouse sequences is 81%. Thus beta,beta-carotene 15,15'-dioxygenase can be considered as being an enzyme that is evolutionarily rather well conserved. We established the expression pattern of beta,beta-carotene 15,15'-dioxygenase in chicken and mouse tissues with a combination of Northern blots and in situ hybridization. The mRNA for beta,beta-carotene 15,15'-dioxygenase was localized primarily in duodenal villi, as well as in liver and in tubular structures of lung and kidney. These new findings demonstrate that beta,beta-carotene 15,15'-dioxygenase is also expressed in epithelial structures, where it serves to provide the tissue-specific vitamin A supply.
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Affiliation(s)
- A Wyss
- F. Hoffmann-La Roche Ltd., Vitamins & Fine Chemicals Division, 4070 Basel, Switzerland.
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32
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Abstract
beta-Carotene might be converted oxidatively to vitamin A- active products in animals by the following three possible routes: 1) central cleavage, 2) sequential excentric cleavage or 3) random cleavage. Central cleavage is strongly favored by stoichiometric studies with tissue homogenates in vitro. To examine the relative importance of these pathways in rats in vivo, an oral dose (5.6 micromol) of all-trans beta-carotene in oil was given to vitamin A-deficient (-A) and to vitamin A-sufficient (+A) adult female Sprague-Dawley rats. Serum and several tissues were analyzed before and 3 h after dosing. The primary products of beta-carotene found in the intestine, serum and liver were retinol, retinyl esters and retinoic acid. Two minor oxidation products of beta-carotene, namely, 5,6-epoxy-beta-carotene and a partially characterized hydroxy-beta-carotene, were present in the stomach and its contents as well as in intestinal preparations. In the intestine, including its contents, of -A rats, very minor amounts of 5,6-epoxyretinyl palmitate and of beta-apocarotenals (8', 10', 12', 14') were identified. The total amount of the beta-apocarotenoids, however, was <5% of the retinoids formed in the intestine from beta-carotene during the same period. Another beta-carotene derivative, with a spectrum similar to that of semi-beta-carotenone, citranaxanthin and beta-apo-6'-carotenal, was also found in the intestinal extract of a -A rat. beta-Apocarotenals, beta-apocarotenols, beta-apocarotenyl esters and beta-apocarotenoic acids were not detected in tissues of +A rats nor in other tissues of -A rats. These findings agree with the view that central cleavage is by far the major pathway for the formation of vitamin A from beta-carotene in healthy rats in vivo.
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Affiliation(s)
- A B Barua
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames 50011, USA
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Yeum KJ, dos Anjos Ferreira AL, Smith D, Krinsky NI, Russell RM. The effect of alpha-tocopherol on the oxidative cleavage of beta-carotene. Free Radic Biol Med 2000; 29:105-14. [PMID: 10980399 DOI: 10.1016/s0891-5849(00)00296-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Two cleavage pathways of beta-carotene have been proposed, one by central cleavage and the other by random (excentric) cleavage. The central cleavage pathway involves the metabolism of beta-carotene at the central double bond (15, 15') to produce retinal by beta-carotene 15, 15'-dioxygenase (E.C.888990988). The random cleavage of beta-carotene produces beta-apo-carotenoids, but the mechanism is not clear. To understand the various mechanisms of beta-carotene cleavage, beta-carotene was incubated with the intestinal postmitochondrial fractions of 10-week-old male rats for 1 h, and cleavage products of beta-carotene were analyzed using reverse-phase, high-performance liquid chromatography (HPLC). We also studied the effects of alpha-tocopherol and NAD(+)/NADH on beta-carotene cleavage. In addition to beta-carotene, we used retinal and beta-apo-14'-carotenoic acid as substrates in these incubations. Beta-apo-14'-carotenoic acid is the two-carbon longer homologue of retinoic acid. In the presence of alpha-tocopherol, beta-carotene was converted exclusively to retinal, whereas in the absence of alpha-tocopherol, both retinal and beta-apo-carotenoids were formed. Retinoic acid was produced from both retinal and beta-apo-14'-carotenoic acid incubations only in the presence of NAD(+). Our data suggest that in the presence of an antioxidant such as alpha-tocopherol, beta-carotene is converted exclusively to retinal by central cleavage. In the absence of an antioxidant, beta-carotene is cleaved randomly by enzyme-related radicals to produce beta-apo-carotenoids, and these beta-apo-carotenoids can be oxidized further to retinoic acid via retinal.
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Affiliation(s)
- K J Yeum
- United States Department of Agriculture, Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
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Wyss A, Wirtz G, Woggon W, Brugger R, Wyss M, Friedlein A, Bachmann H, Hunziker W. Cloning and expression of beta,beta-carotene 15,15'-dioxygenase. Biochem Biophys Res Commun 2000; 271:334-6. [PMID: 10799297 DOI: 10.1006/bbrc.2000.2619] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta,beta-Carotene 15,15'-dioxygenase cleaves beta-carotene into two molecules of retinal and is therefore the key enzyme in beta-carotene metabolism to vitamin A. In the present study, it was possible to enrich the chicken beta,beta-carotene 15,15'-dioxygenase to such an extent that partial amino acid sequence information could be obtained to design degenerate oligonucleotides. With RT-PCR a cDNA fragment could be obtained and used subsequently in a radioactive screening of a chicken duodenal expression library. We cloned the first eukaryotic beta,beta-carotene 15,15'-dioxygenase which symmetrically cleaves beta-carotene at the 15,15'-double bond.
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Affiliation(s)
- A Wyss
- Vitamins & Fine Chemicals Division, F. Hoffmann-LaRoche Ltd., Basel, 4070, Switzerland.
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A novel pharmacokinetic approach to determine the relative efficiency of conversion of B-carotene to vitamin A in rats and children. Nutr Res 2000. [DOI: 10.1016/s0271-5317(00)00153-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
There are two major dietary sources of vitamin A: easily absorbed retinyl palmitate in foods of animal origin, and poorly bioavailable carotenoids from plant foods. Plasma retinol is tightly controlled, probably by regulation of retinol-binding protein (RBP) formation in the liver, and only hormonal factors (e.g. oral contraceptives) and infection will alter the homeostasis. Delivery of retinol to the tissues is facilitated by the RBP-retinol complex; however, there is evidence that this mechanism can be bypassed when very high doses of vitamin A are given. Some retinyl ester may be released to tissues from chylomicrons when the latter bind to tissue lipoprotein receptors during their passage from the gut to the liver following a meal. High-dose vitamin A therapy is a means of rapidly improving vitamin A status in persons with sub-optimal vitamin A nutrition but there are dangers of toxic symptoms (e.g. teratogenicity) from excess vitamin A usage. Evidence is presented to suggest that the plasma retinol: RBP may be a guide to optimal vitamin A status, since values less than one frequently occur in less-developed countries and during infection. In contrast to plasma retinol, plasma carotenoids reflect the dietary intake of plant foods. However, absorption is limited by poor bioavailability and a saturable uptake mechanism in competition with other phytochemicals. Recent work on bioavailability suggests that the calculation of plant food vitamin A activity should be re-examined. Illness has little influence on plasma levels except by suppressing appetite. Carotenoids are generally regarded as non-toxic yet intervention studies with beta-carotene in smokers have been associated with increased lung cancer and heart disease. Some carotenoids are important as vitamin A precursors, but the physiological importance of their antioxidant properties is not known and consequently the amount needed for optimal nutrition is uncertain.
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Affiliation(s)
- D I Thurnham
- Northern Ireland Centre for Diet and Health, University of Ulster, Coleraine, UK.
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Affiliation(s)
- X D Wang
- Gastrointestinal Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA
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During A, Albaugh G, Smith JC. Characterization of beta-carotene 15,15'-dioxygenase activity in TC7 clone of human intestinal cell line Caco-2. Biochem Biophys Res Commun 1998; 249:467-74. [PMID: 9712720 DOI: 10.1006/bbrc.1998.9160] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to identify mammalian cell line(s) which possess intrinsic enzymatic activity of beta-carotene 15, 15'-dioxygenase. This enzyme (EC1.13.11.21) converts beta-carotene to retinal (precursor of retinol and retinoic acid). To assess activity, cellular enzyme preparations were incubated with beta-carotene for 60 min; retinal formed was quantified by HPLC. Activity was not detected in IPEC-1, HepG2, HL60, Wurzburg, or parent Caco-2 cell lines. However, two subclones of Caco-2, PF11 and TC7, possessed activity (2.5 and 14.7 pmol/h.mg, respectively). Using the enzyme preparation of TC7 cells, retinal formation was linear with incubation time and protein concentration; Km and Vm values were 1.6 microM and 23.8 pmol/h.mg, respectively. In addition, when TC7 cells were maintained in serum-free medium, activity was increased 8.2-fold after 19 days of postconfluency. Finally, 48 h incubation with beta-carotene (delivered to TC7 cells in Tween 40) resulted in a 1.7-fold increase of dioxygenase activity and the appearance of vitamin A (9.3 pmol/mg protein). However, retinoic acid was not detected under our experimental conditions. In sum, the TC7 subclone of the Caco-2 cell line possesses beta-carotene 15, 15'-dioxygenase activity and thus can be useful in future investigations of human carotenoid metabolism.
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Affiliation(s)
- A During
- Beltsville Human Nutrition Research Center, USDA-ARS, Beltsville, Maryland, 20705, USA
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Wang XD, Krinsky NI. Identification and quantification of retinoic acid and other metabolites from beta-carotene excentric cleavage in human intestine in vitro and ferret intestine in vivo. Methods Enzymol 1997; 282:117-30. [PMID: 9330282 DOI: 10.1016/s0076-6879(97)82101-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- X D Wang
- United States Department of Agriculture, Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts 02111, USA
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Abstract
The enzyme beta-carotene-15,15'-dioxygenase from guinea pig intestinal mucosa was found to cleave beta-carotene and produce 2 mol of retinal for 1 mol of beta-carotene. However, extensive evidence exists also for random (excentric) cleavage, resulting in retinoic acid and retinal, with a preponderance of apocarotenals formed as intermediates.
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Affiliation(s)
- G Wolf
- Department of Nutritional Sciences, University of California, Berkeley 94720, USA
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