1
|
Barreto JVDO, Casanova LM, Junior AN, Reis-Mansur MCPP, Vermelho AB. Microbial Pigments: Major Groups and Industrial Applications. Microorganisms 2023; 11:2920. [PMID: 38138065 PMCID: PMC10745774 DOI: 10.3390/microorganisms11122920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
Microbial pigments have many structures and functions with excellent characteristics, such as being biodegradable, non-toxic, and ecologically friendly, constituting an important source of pigments. Industrial production presents a bottleneck in production cost that restricts large-scale commercialization. However, microbial pigments are progressively gaining popularity because of their health advantages. The development of metabolic engineering and cost reduction of the bioprocess using industry by-products opened possibilities for cost and quality improvements in all production phases. We are thus addressing several points related to microbial pigments, including the major classes and structures found, the advantages of use, the biotechnological applications in different industrial sectors, their characteristics, and their impacts on the environment and society.
Collapse
Affiliation(s)
| | | | | | | | - Alane Beatriz Vermelho
- Bioinovar Laboratory, Institute of Microbiology Paulo de Goes, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (J.V.d.O.B.); (L.M.C.); (A.N.J.); (M.C.P.P.R.-M.)
| |
Collapse
|
2
|
Lee TY, Farah N, Chin VK, Lim CW, Chong PP, Basir R, Lim WF, Loo YS. Medicinal benefits, biological, and nanoencapsulation functions of riboflavin with its toxicity profile: A narrative review. Nutr Res 2023; 119:1-20. [PMID: 37708600 DOI: 10.1016/j.nutres.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/22/2023] [Accepted: 08/22/2023] [Indexed: 09/16/2023]
Abstract
Riboflavin is a precursor of the essential coenzymes flavin mononucleotide and flavin adenine dinucleotide. Both possess antioxidant properties and are involved in oxidation-reduction reactions, which have a significant impact on energy metabolism. Also, the coenzymes participate in metabolism of pyridoxine, niacin, folate, and iron. Humans must obtain riboflavin through their daily diet because of the lack of programmed enzymatic machineries for de novo riboflavin synthesis. Because of its physiological nature and fast elimination from the human body when in excess, riboflavin consumed is unlikely to induce any negative effects or develop toxicity in humans. The use of riboflavin in pharmaceutical and clinical contexts has been previously explored, including for preventing and treating oxidative stress and reperfusion oxidative damage, creating synergistic compounds to mitigate colorectal cancer, modulating blood pressure, improving diabetes mellitus comorbidities, as well as neuroprotective agents and potent photosensitizer in killing bloodborne pathogens. Thus, the goal of this review is to provide a comprehensive understanding of riboflavin's biological applications in medicine, key considerations of riboflavin safety and toxicity, and a brief overview on the nanoencapsulation of riboflavin for various functions including the treatment of a range of diseases, photodynamic therapy, and cellular imaging.
Collapse
Affiliation(s)
- Tze Yan Lee
- Perdana University School of Liberal Arts, Science and Technology (PUScLST), Wisma Chase Perdana, Changkat Semantan, Damansara Heights, 50490 Kuala Lumpur, Malaysia.
| | - Nuratiqah Farah
- Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Voon Kin Chin
- Faculty of Medicine, Nursing, and Health Sciences, SEGi University, Kota Damansara, 47810 Petaling Jaya, Selangor, Malaysia
| | - Chee Woei Lim
- Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Pei Pei Chong
- School of Biosciences, Taylor's University, No. 1, Jalan Taylor's, 47500 Subang Jaya, Selangor, Malaysia
| | - Rusliza Basir
- Department of Human Anatomy, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Wai Feng Lim
- Sunway Medical Centre, 47500 Petaling Jaya, Selangor, Malaysia
| | - Yan Shan Loo
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| |
Collapse
|
3
|
Püschel D, Hédé S, Maisuls I, Höfert SP, Woschko D, Kühnemuth R, Felekyan S, Seidel CAM, Czekelius C, Weingart O, Strassert CA, Janiak C. Enhanced Solid-State Fluorescence of Flavin Derivatives by Incorporation in the Metal-Organic Frameworks MIL-53(Al) and MOF-5. Molecules 2023; 28:molecules28062877. [PMID: 36985849 PMCID: PMC10055669 DOI: 10.3390/molecules28062877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
The flavin derivatives 10-methyl-isoalloxazine (MIA) and 6-fluoro-10-methyl-isoalloxazine (6F-MIA) were incorporated in two alternative metal-organic frameworks, (MOFs) MIL-53(Al) and MOF-5. We used a post-synthetic, diffusion-based incorporation into microcrystalline MIL-53 powders with one-dimensional (1D) pores and an in-situ approach during the synthesis of MOF-5 with its 3D channel network. The maximum amount of flavin dye incorporation is 3.9 wt% for MIA@MIL-53(Al) and 1.5 wt% for 6F-MIA@MIL-53(Al), 0.85 wt% for MIA@MOF-5 and 5.2 wt% for 6F-MIA@MOF-5. For the high incorporation yields the probability to have more than one dye molecule in a pore volume is significant. As compared to the flavins in solution, the fluorescence spectrum of these flavin@MOF composites is broadened at the bathocromic side especially for MIA. Time-resolved spectroscopy showed that multi-exponential fluorescence lifetimes were needed to describe the decays. The fluorescence-weighted lifetime of flavin@MOF of 4 ± 1 ns also corresponds to those in solution but is significantly prolonged compared to the solid flavin dyes with less than 1 ns, thereby confirming the concept of "solid solutions" for dye@MOF composites. The fluorescence quantum yield (ΦF) of the flavin@MOF composites is about half of the solution but is significantly higher compared to the solid flavin dyes. Both the fluorescence lifetime and quantum yield of flavin@MOF decrease with the flavin loading in MIL-53 due to the formation of various J-aggregates. Theoretical calculations using plane-wave and QM/MM methods are in good correspondence with the experimental results and explain the electronic structures as well as the photophysical properties of crystalline MIA and the flavin@MOF composites. In the solid flavins, π-stacking interactions of the molecules lead to a charge transfer state with low oscillator strength resulting in aggregation-caused quenching (ACQ) with low lifetimes and quantum yields. In the MOF pores, single flavin molecules represent a major population and the computed MIA@MOF structures do not find π-stacking interactions with the pore walls but only weak van-der-Waals contacts which reasons the enhanced fluorescence lifetime and quantum yield of the flavins in the composites compared to their neat solid state. To analyze the orientation of flavins in MOFs, we measured fluorescence anisotropy images of single flavin@MOF-5 crystals and a static ensemble flavin@MIL53 microcrystals, respectively. Based on image information, anisotropy distributions and overall curve of the time-resolved anisotropy curves combined with theoretical calculations, we can prove that all fluorescent flavins species have a defined and rather homogeneous orientation in the MOF framework. In MIL-53, the transition dipole moments of flavins are orientated along the 1D channel axis, whereas in MOF-5 we resolved an average orientation that is tilted with respect to the cubic crystal lattice. Notably, the more hydrophobic 6F-MIA exhibits a higher degree order than MIA. The flexible MOF MIL-53(Al) was optimized essentially to the experimental large-pore form in the guest-free state with QuantumEspresso (QE) and with MIA molecules in the pores the structure contracted to close to the experimental narrow-pore form which was also confirmed by PXRD. In summary, the incorporation of flavins in MOFs yields solid-state materials with enhanced rigidity, stabilized conformation, defined orientation and reduced aggregations of the flavins, leading to increased fluorescence lifetime and quantum yield as controllable photo-luminescent and photo-physical properties.
Collapse
Affiliation(s)
- Dietrich Püschel
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Simon Hédé
- Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Iván Maisuls
- Institut für Anorganische und Analytische Chemie, CeNTech, CiMIC, SoN, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, D-48149 Münster, Germany
| | - Simon-Patrick Höfert
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Dennis Woschko
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Ralf Kühnemuth
- Institut für Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Suren Felekyan
- Institut für Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Claus A M Seidel
- Institut für Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Constantin Czekelius
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Oliver Weingart
- Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, CeNTech, CiMIC, SoN, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, D-48149 Münster, Germany
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| |
Collapse
|
4
|
Fine spectral tuning of a flavin-binding fluorescent protein for multicolor imaging. J Biol Chem 2023; 299:102977. [PMID: 36738792 PMCID: PMC10023982 DOI: 10.1016/j.jbc.2023.102977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/20/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Flavin-binding fluorescent proteins are promising genetically encoded tags for microscopy. However, spectral properties of their chromophores (riboflavin, flavin mononucleotide, and flavin adenine dinucleotide) are notoriously similar even between different protein families, which limits applications of flavoproteins in multicolor imaging. Here, we present a palette of 22 finely tuned fluorescent tags based on the thermostable LOV domain from Chloroflexus aggregans. We performed site saturation mutagenesis of three amino acid positions in the flavin-binding pocket, including the photoactive cysteine, to obtain variants with fluorescence emission maxima uniformly covering the wavelength range from 486 to 512 nm. We demonstrate three-color imaging based on spectral separation and two-color fluorescence lifetime imaging of bacteria, as well as two-color imaging of mammalian cells (HEK293T), using the proteins from the palette. These results highlight the possibility of fine spectral tuning of flavoproteins and pave the way for further applications of flavin-binding fluorescent proteins in fluorescence microscopy.
Collapse
|
5
|
Li A, Wang Y, Kulyar MFEA, Iqbal M, Lai R, Zhu H, Li K. Environmental microplastics exposure decreases antioxidant ability, perturbs gut microbial homeostasis and metabolism in chicken. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159089. [PMID: 36174690 DOI: 10.1016/j.scitotenv.2022.159089] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/21/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
The widespread presence and accumulation of microplastics (MPs) in organisms has led to their recognition as a major global ecological issue. There is a lot of data on how MPs affect the physiology and behavior of aquatic species, but the effects of MPs on poultry are less understood. Therefore, we aimed to explore the adverse effects and mechanisms of MPs exposure to chicken health. Results indicated that MPs exposure decreased growth performance and antioxidant ability and impaired chickens' intestine, liver, kidney, and spleen. Additionally, the gut microbiota in chickens exposed to MPs showed a significant decrease in alpha diversity, accompanied by significant alternations in taxonomic compositions. Microbial taxonomic investigation indicated that exposure to MPs resulted in a significant increase in the relative proportions of 11 genera and a distinct decline in the relative percentages of 3 phyla and 52 genera. Among decreased bacterial taxa, 11 genera even couldn't be detected in the gut microbiota of chickens exposed to MPs. Metabolomics analysis indicated that 2561 (1190 up-regulated, 1371 down-regulated) differential metabolites were identified, mainly involved in 5 metabolic pathways, including D-amino acid metabolism, ABC transporters, vitamin digestion and absorption, mineral absorption, and histidine metabolism. Taken together, this study indicated that MPs exposure resulted in adverse health outcomes for chickens by disturbing gut microbial homeostasis and intestinal metabolism. This study also provided motivation for environmental agencies worldwide to regulate the application and disposal of plastic products and decrease environmental contamination.
Collapse
Affiliation(s)
- Aoyun Li
- Institute of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yingli Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | | | - Mudassar Iqbal
- Faculty of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - Renhao Lai
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Huaisen Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Kun Li
- Institute of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China.
| |
Collapse
|
6
|
Pimviriyakul P, Chaiyen P. Formation and stabilization of C4a-hydroperoxy-FAD by the Arg/Asn pair in HadA monooxygenase. FEBS J 2023; 290:176-195. [PMID: 35942637 DOI: 10.1111/febs.16591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/25/2022] [Accepted: 08/08/2022] [Indexed: 01/14/2023]
Abstract
HadA monooxygenase catalyses the detoxification of halogenated phenols and nitrophenols via dehalogenation and denitration respectively. C4a-hydroperoxy-FAD is a key reactive intermediate wherein its formation, protonation and stabilization reflect enzyme efficiency. Herein, transient kinetics, site-directed mutagenesis and pH-dependent behaviours of HadA reaction were employed to identify key features stabilizing C4a-adducts in HadA. The formation of C4a-hydroperoxy-FAD is pH independent, whereas its decay and protonation of distal oxygen are associated with pKa values of 8.5 and 8.4 respectively. These values are correlated with product formation within a pH range of 7.6-9.1, indicating the importance of adduct stabilization to enzymatic efficiency. We identified Arg101 as a key residue for reduced FAD (FADH- ) binding and C4a-hydroperoxy-FAD formation due to the loss of these abilities as well as enzyme activity in HadAR101A and HadAR101Q . Mutations of the neighbouring Asn447 do not affect the rate of C4a-hydroperoxy-FAD formation; however, they impair FADH- binding. The disruption of Arg101/Asn447 hydrogen bond networking in HadAN447A increases the pKa value of C4a-hydroperoxy-FAD decay to 9.5; however, this pKa was not altered in HadAN447D (pKa of 8.5). Thus, Arg101/Asn447 pair should provide important interactions for FADH- binding and maintain the pKa associated with H2 O2 elimination from C4a-hydroperoxy-FAD in HadA. In the presence of substrate, the formation of C4a-hydroxy-FAD at the hydroxylation step is pH insensitive, and it dehydrates to form the oxidized FAD with pKa of 7.9. This structural feature might help elucidate how the reactive intermediate was stabilized in other flavin-dependent monooxygenases.
Collapse
Affiliation(s)
- Panu Pimviriyakul
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| |
Collapse
|
7
|
Hassanin HA. Investigation on the interaction of riboflavin with aquacobalamin (Vitamin B12): A fluorescence quenching study. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.113968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
8
|
Cariello M, Dietrich B, Thomson L, Gauci V, Boyer A, Sproules S, Cooke G, Seddon A, Adams DJ. A Self‐Assembling Flavin for Visible Photooxidation. Chemistry 2022; 28:e202201725. [PMID: 35722972 PMCID: PMC9541220 DOI: 10.1002/chem.202201725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Indexed: 11/06/2022]
Abstract
A new flavin‐based gelator is reported which forms micellar structures at high pH and gels at low pH. This flavin can be used for the photooxidation of thiols under visible light, with the catalytic efficiency being linked to the self‐assembled structures present.
Collapse
Affiliation(s)
| | - Bart Dietrich
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| | - Lisa Thomson
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| | - Valentina Gauci
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| | - Alistair Boyer
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| | | | - Graeme Cooke
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| | - Annela Seddon
- School of Physics, HH Wills Physics Laboratory University of Bristol Tyndall Avenue Bristol BS8 1TL UK
| | - Dave J. Adams
- School of Chemistry University of Glasgow Glasgow G12 8QQ UK
| |
Collapse
|
9
|
Khandelwal H, Mutyala S, Kim M, Eun Song Y, Li S, Jang M, Oh SE, Rae Kim J. Colorimetric isolation of a novel electrochemically active Pseudomonas strain using tungsten nanorods for bioelectrochemical applications. Bioelectrochemistry 2022; 146:108136. [DOI: 10.1016/j.bioelechem.2022.108136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/15/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
|
10
|
Bloor S, Michurin I, Titchiner GR, Leys D. Prenylated flavins: structures and mechanisms. FEBS J 2022; 290:2232-2245. [PMID: 35073609 DOI: 10.1111/febs.16371] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/05/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
Abstract
The UbiX/UbiD system is widespread in microbes and responsible for the reversible decarboxylation of unsaturated carboxylic acids. The UbiD enzyme catalyzes this unusual reaction using a prenylated flavin (prFMN) as cofactor, the latter formed by the flavin prenyltransferase UbiX. A detailed picture of the biochemistry of flavin prenylation, oxidative maturation, and covalent catalysis underpinning reversible decarboxylation is emerging. This reveals the prFMN cofactor can undergo a wide range of transformations, complemented by considerable UbiD-variability. These provide a blueprint for biotechnological applications aimed at producing hydrocarbons or aromatic C-H activation through carboxylation.
Collapse
Affiliation(s)
- Samuel Bloor
- Department of Chemistry, Manchester Institute of Biotechnology, UK
| | | | | | - David Leys
- Department of Chemistry, Manchester Institute of Biotechnology, UK
| |
Collapse
|
11
|
Wu C, Li Y, Cheng Z, Wang P, Ma Z, Liu K, Cheng Y, Zhou Y, Lin X, Shao X, Yang Y, Li H, Fang L. Cell-penetrating riboflavin conjugate for antitumor photodynamic therapy. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.01.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
12
|
Abstract
Current strategies of combating bacterial infections are limited and involve the use of antibiotics and preservatives. Each of these agents has generally inadequate efficacy and a number of serious adverse effects. Thus, there is an urgent need for new antimicrobial drugs and food preservatives with higher efficacy and lower toxicity. Edible plants have been used in medicine since ancient times and are well known for their successful antimicrobial activity. Often photosensitizers are present in many edible plants; they could be a promising source for a new generation of drugs and food preservatives. The use of photodynamic therapy allows enhancement of antimicrobial properties in plant photosensitizers. The purpose of this review is to present the verified data on the antimicrobial activities of photodynamic phytochemicals in edible species of the world’s flora, including the various mechanisms of their actions.
Collapse
|
13
|
Xu J, Wang C, Ban R. Improving riboflavin production by modifying related metabolic pathways in Bacillus subtilis. Lett Appl Microbiol 2021; 74:78-83. [PMID: 34704264 DOI: 10.1111/lam.13584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/25/2021] [Indexed: 12/01/2022]
Abstract
Riboflavin is a feed additive, food additive and clinical drug, with a significant annual demand of nearly 8000 t. Fermentation using recombinant Bacillus subtilis is currently one of the most important industrial production method for riboflavin. First, a suitable medium was selected and the expression of the ureABC operon was modified. The ykgB gene was overexpressed in B. subtilis RX10, the production of the derivative strain RX20 was increased to 4·61 g l-1 riboflavin, and the yield was increased to 52 mg riboflavin g-1 glucose. The relative transcription level of pyr operon in RX20 was reduced to 71%, the production of the derivative strain RX21 was increased to 5·82 g l-1 riboflavin, and the yield was 76 mg riboflavin g-1 glucose. The start codon of the pyrE gene in RX21 was modified to 'TTG', the production of the derivative strain RX22 was increased to 7·01 g l-1 riboflavin, and the yield was 89 mg riboflavin g-1 glucose. These results indicated that overexpression of the ykgB gene and reduction of the metabolic flux of de novo synthesis of pyrimidine nucleotides were beneficial to the synthesis of riboflavin.
Collapse
Affiliation(s)
- J Xu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - C Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - R Ban
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| |
Collapse
|
14
|
Hawley KL, Montezuma-Rusca JM, Delgado KN, Singh N, Uversky VN, Caimano MJ, Radolf JD, Luthra A. Structural Modeling of the Treponema pallidum Outer Membrane Protein Repertoire: a Road Map for Deconvolution of Syphilis Pathogenesis and Development of a Syphilis Vaccine. J Bacteriol 2021; 203:e0008221. [PMID: 33972353 PMCID: PMC8407342 DOI: 10.1128/jb.00082-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/27/2021] [Indexed: 01/11/2023] Open
Abstract
Treponema pallidum, an obligate human pathogen, has an outer membrane (OM) whose physical properties, ultrastructure, and composition differ markedly from those of phylogenetically distant Gram-negative bacteria. We developed structural models for the outer membrane protein (OMP) repertoire (OMPeome) of T. pallidum Nichols using solved Gram-negative structures, computational tools, and small-angle X-ray scattering (SAXS) of selected recombinant periplasmic domains. The T. pallidum "OMPeome" harbors two "stand-alone" proteins (BamA and LptD) involved in OM biogenesis and four paralogous families involved in the influx/efflux of small molecules: 8-stranded β-barrels, long-chain-fatty-acid transporters (FadLs), OM factors (OMFs) for efflux pumps, and T. pallidum repeat proteins (Tprs). BamA (TP0326), the central component of a β-barrel assembly machine (BAM)/translocation and assembly module (TAM) hybrid, possesses a highly flexible polypeptide-transport-associated (POTRA) 1-5 arm predicted to interact with TamB (TP0325). TP0515, an LptD ortholog, contains a novel, unstructured C-terminal domain that models inside the β-barrel. T. pallidum has four 8-stranded β-barrels, each containing positively charged extracellular loops that could contribute to pathogenesis. Three of five FadL-like orthologs have a novel α-helical, presumptively periplasmic C-terminal extension. SAXS and structural modeling further supported the bipartite membrane topology and tridomain architecture of full-length members of the Tpr family. T. pallidum's two efflux pumps presumably extrude noxious small molecules via four coexpressed OMFs with variably charged tunnels. For BamA, LptD, and OMFs, we modeled the molecular machines that deliver their substrates into the OM or external milieu. The spirochete's extended families of OM transporters collectively confer a broad capacity for nutrient uptake. The models also furnish a structural road map for vaccine development. IMPORTANCE The unusual outer membrane (OM) of T. pallidum, the syphilis spirochete, is the ultrastructural basis for its well-recognized capacity for invasiveness, immune evasion, and persistence. In recent years, we have made considerable progress in identifying T. pallidum's repertoire of OMPs. Here, we developed three-dimensional (3D) models for the T. pallidum Nichols OMPeome using structural modeling, bioinformatics, and solution scattering. The OM contains three families of OMP transporters, an OMP family involved in the extrusion of noxious molecules, and two "stand-alone" proteins involved in OM biogenesis. This work represents a major advance toward elucidating host-pathogen interactions during syphilis; understanding how T. pallidum, an extreme auxotroph, obtains a wide array of biomolecules from its obligate human host; and developing a vaccine with global efficacy.
Collapse
Affiliation(s)
- Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, Connecticut, USA
| | - Jairo M. Montezuma-Rusca
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases, UConn Health, Farmington, Connecticut, USA
| | | | - Navreeta Singh
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Melissa J. Caimano
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Justin D. Radolf
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
- Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
| | - Amit Luthra
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| |
Collapse
|
15
|
Liu J, Han S, Hu Y, Pao CW. Fabrication and characterization of a novel PMO containing riboflavin-5'-phosphate sodium salt for sensitive detection of pesticide ferbam. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
16
|
Tunable Properties of Nature-Inspired N, N'-Alkylated Riboflavin Semiconductors. Molecules 2020; 26:molecules26010027. [PMID: 33374613 PMCID: PMC7793104 DOI: 10.3390/molecules26010027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/22/2022] Open
Abstract
A series of novel soluble nature-inspired flavin derivatives substituted with short butyl and bulky ethyl-adamantyl alkyl groups was prepared via simple and straightforward synthetic approach with moderate to good yields. The comprehensive characterization of the materials, to assess their application potential, has demonstrated that the modification of the conjugated flavin core enables delicate tuning of the absorption and emission properties, optical bandgap, frontier molecular orbital energies, melting points, and thermal stability. Moreover, the thin films prepared thereof exhibit smooth and homogeneous morphology with generally high stability over time.
Collapse
|
17
|
Molin M, Logg K, Bodvard K, Peeters K, Forsmark A, Roger F, Jörhov A, Mishra N, Billod JM, Amir S, Andersson M, Eriksson LA, Warringer J, Käll M, Blomberg A. Protein kinase A controls yeast growth in visible light. BMC Biol 2020; 18:168. [PMID: 33198745 PMCID: PMC7667738 DOI: 10.1186/s12915-020-00867-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/09/2020] [Indexed: 01/07/2023] Open
Abstract
Background A wide variety of photosynthetic and non-photosynthetic species sense and respond to light, having developed protective mechanisms to adapt to damaging effects on DNA and proteins. While the biology of UV light-induced damage has been well studied, cellular responses to stress from visible light (400–700 nm) remain poorly understood despite being a regular part of the life cycle of many organisms. Here, we developed a high-throughput method for measuring growth under visible light stress and used it to screen for light sensitivity in the yeast gene deletion collection. Results We found genes involved in HOG pathway signaling, RNA polymerase II transcription, translation, diphthamide modifications of the translational elongation factor eEF2, and the oxidative stress response to be required for light resistance. Reduced nuclear localization of the transcription factor Msn2 and lower glycogen accumulation indicated higher protein kinase A (cAMP-dependent protein kinase, PKA) activity in many light-sensitive gene deletion strains. We therefore used an ectopic fluorescent PKA reporter and mutants with constitutively altered PKA activity to show that repression of PKA is essential for resistance to visible light. Conclusion We conclude that yeast photobiology is multifaceted and that protein kinase A plays a key role in the ability of cells to grow upon visible light exposure. We propose that visible light impacts on the biology and evolution of many non-photosynthetic organisms and have practical implications for how organisms are studied in the laboratory, with or without illumination.
Collapse
Affiliation(s)
- Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden. .,Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
| | - Katarina Logg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Kristofer Bodvard
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Ken Peeters
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Annabelle Forsmark
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Friederike Roger
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anna Jörhov
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Neha Mishra
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Horizon Discovery, Cambridge, CB25 9TL, UK
| | - Jean-Marc Billod
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Bio-Me A/S, Oslo Science Park, Gaustadalléen, 210349, Oslo, Norway
| | - Sabiha Amir
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mikael Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jonas Warringer
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mikael Käll
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Anders Blomberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
| |
Collapse
|
18
|
Abstract
Flavin-dependent enzymes catalyze a wide variety of biological reactions that are important for all types of living organisms. Knowledge gained from studying the chemistry and biological functions of flavins and flavin-dependent enzymes has continuously made significant contributions to the development of the fields of enzymology and metabolism from the 1970s until now. The enzymes have been applied in various applications such as use as biocatalysts in synthetic processes for the chemical and pharmaceutical industries or in the biodetoxification and bioremediation of toxic or unwanted compounds, and as biosensors or biodetection tools for quantifying various agents of interest. Many flavin-dependent enzymes are also prime targets for drug development. Based on their reaction mechanisms, they can be classified into five categories: oxidase, dehydrogenase, monooxygenase, reductase, and redox neutral flavin-dependent enzymes. In this chapter, the general properties of flavin-dependent enzymes and the nature of their chemical reactions are discussed, along with their practical applications.
Collapse
|
19
|
Melin F, Hellwig P. Redox Properties of the Membrane Proteins from the Respiratory Chain. Chem Rev 2020; 120:10244-10297. [DOI: 10.1021/acs.chemrev.0c00249] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Frederic Melin
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| | - Petra Hellwig
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| |
Collapse
|
20
|
Mitochondrial and Peroxisomal Alterations Contribute to Energy Dysmetabolism in Riboflavin Transporter Deficiency. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:6821247. [PMID: 32855765 PMCID: PMC7443020 DOI: 10.1155/2020/6821247] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/07/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022]
Abstract
Riboflavin transporter deficiency (RTD) is a childhood-onset neurodegenerative disorder characterized by progressive pontobulbar palsy, sensory and motor neuron degeneration, sensorineural hearing loss, and optic atrophy. As riboflavin (RF) is the precursor of FAD and FMN, we hypothesize that both mitochondrial and peroxisomal energy metabolism pathways involving flavoproteins could be directly affected in RTD, thus impacting cellular redox status. In the present work, we used induced pluripotent stem cells (iPSCs) from RTD patients to investigate morphofunctional features, focusing on mitochondrial and peroxisomal compartments. Using this model, we document the following RTD-associated alterations: (i) abnormal colony-forming ability and loss of cell-cell contacts, revealed by light, electron, and confocal microscopy, using tight junction marker ZO-1; (ii) mitochondrial ultrastructural abnormalities, involving shape, number, and intracellular distribution of the organelles, as assessed by focused ion beam/scanning electron microscopy (FIB/SEM); (iii) redox imbalance, with high levels of superoxide anion, as assessed by MitoSOX assay accompanied by abnormal mitochondrial polarization state, evaluated by JC-1 staining; (iv) altered immunofluorescence expression of antioxidant systems, namely, glutathione, superoxide dismutase 1 and 2, and catalase, as assessed by quantitatively evaluated confocal microscopy; and (v) peroxisomal downregulation, as demonstrated by levels and distribution of fatty acyl β-oxidation enzymes. RF supplementation results in amelioration of cell phenotype and rescue of redox status, which was associated to improved ultrastructural features of mitochondria, thus strongly supporting patient treatment with RF, to restore mitochondrial- and peroxisomal-related aspects of energy dysmetabolism and oxidative stress in RTD syndrome.
Collapse
|
21
|
Schall P, Marutschke L, Grimm B. The Flavoproteome of the Model Plant Arabidopsis thaliana. Int J Mol Sci 2020; 21:ijms21155371. [PMID: 32731628 PMCID: PMC7432721 DOI: 10.3390/ijms21155371] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/22/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022] Open
Abstract
Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are essential cofactors for enzymes, which catalyze a broad spectrum of vital reactions. This paper intends to compile all potential FAD/FMN-binding proteins encoded by the genome of Arabidopsis thaliana. Several computational approaches were applied to group the entire flavoproteome according to (i) different catalytic reactions in enzyme classes, (ii) the localization in subcellular compartments, (iii) different protein families and subclasses, and (iv) their classification to structural properties. Subsequently, the physiological significance of several of the larger flavoprotein families was highlighted. It is conclusive that plants, such as Arabidopsis thaliana, use many flavoenzymes for plant-specific and pivotal metabolic activities during development and for signal transduction pathways in response to biotic and abiotic stress. Thereby, often two up to several homologous genes are found encoding proteins with high protein similarity. It is proposed that these gene families for flavoproteins reflect presumably their need for differential transcriptional control or the expression of similar proteins with modified flavin-binding properties or catalytic activities.
Collapse
|
22
|
Abstract
The reversible (de)carboxylation of unsaturated carboxylic acids is carried out by the UbiX-UbiD system, ubiquitously present in microbes. The biochemical basis of this challenging reaction has recently been uncovered by the discovery of the UbiD cofactor, prenylated FMN (prFMN). This heavily modified flavin is synthesized by the flavin prenyltransferase UbiX, which catalyzes the non-metal dependent prenyl transfer from dimethylallyl(pyro)phosphate (DMAP(P)) to the flavin N5 and C6 positions, creating a fourth non-aromatic ring. Following prenylation, prFMN undergoes oxidative maturation to form the iminium species required for UbiD activity. prFMNiminium acts as a prostethic group and is bound via metal ion mediated interactions between UbiD and the prFMNiminium phosphate moiety. The modified isoalloxazine ring is place adjacent to the E(D)-R-E UbiD signature sequent motif. The fungal ferulic acid decarboxylase Fdc from Aspergillus niger has emerged as a UbiD-model system, and has yielded atomic level insight into the prFMNiminium mediated (de)carboxylation. A wealth of data now supports a mechanism reliant on reversible 1,3 dipolar cycloaddition between substrate and cofactor for this enzyme. This poses the intriguing question whether a similar mechanism is used by all UbiD enzymes, especially those that act as carboxylases on inherently more difficult substrates such as phenylphosphate or benzene/naphthalene. Indeed, considerable variability in terms of oligomerization, domain motion and active site structure is now reported for the UbiD family.
Collapse
Affiliation(s)
- Annica Saaret
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Arune Balaikaite
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, United Kingdom
| | - David Leys
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, United Kingdom.
| |
Collapse
|
23
|
Expression and purification of the 5'-nucleotidase YitU from Bacillus species: its enzymatic properties and possible applications in biotechnology. Appl Microbiol Biotechnol 2020; 104:2957-2972. [PMID: 32040605 PMCID: PMC7062661 DOI: 10.1007/s00253-020-10428-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 01/17/2020] [Accepted: 02/03/2020] [Indexed: 11/05/2022]
Abstract
5’-Nucleotidases (EC 3.1.3.5) are enzymes that catalyze the hydrolytic dephosphorylation of 5′-ribonucleotides and 5′-deoxyribonucleotides to their corresponding nucleosides plus phosphate. In the present study, to search for new genes encoding 5′-nucleotidases specific for purine nucleotides in industrially important Bacillus species, “shotgun” cloning and the direct selection of recombinant clones grown in purine nucleosides at inhibitory concentrations were performed in the Escherichia coli GS72 strain, which is sensitive to these compounds. As a result, orthologous yitU genes from Bacillus subtilis and Bacillus amyloliquefaciens, whose products belong to the ubiquitous haloacid dehalogenase superfamily (HADSF), were selected and found to have a high sequence similarity of 87%. B. subtilis YitU was produced in E. coli as an N-terminal hexahistidine-tagged protein, purified and biochemically characterized as a soluble 5′-nucleotidase with broad substrate specificity with respect to various deoxyribo- and ribonucleoside monophosphates: dAMP, GMP, dGMP, CMP, AMP, XMP, IMP and 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranosyl 5′-monophosphate (AICAR-P). However, the preferred substrate for recombinant YitU was shown to be flavin mononucleotide (FMN). B. subtilis and B. amyloliquefaciens yitU overexpression increased riboflavin (RF) and 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) accumulation and can be applied to breed highly performing RF- and AICAR-producing strains.
Collapse
|
24
|
Roy A, Pittman M, Saitta ET, Kaye TG, Xu X. Recent advances in amniote palaeocolour reconstruction and a framework for future research. Biol Rev Camb Philos Soc 2020; 95:22-50. [PMID: 31538399 PMCID: PMC7004074 DOI: 10.1111/brv.12552] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 01/24/2023]
Abstract
Preserved melanin pigments have been discovered in fossilised integumentary appendages of several amniote lineages (fishes, frogs, snakes, marine reptiles, non-avialan dinosaurs, birds, and mammals) excavated from lagerstätten across the globe. Melanisation is a leading factor in organic integument preservation in these fossils. Melanin in extant vertebrates is typically stored in rod- to sphere-shaped, lysosome-derived, membrane-bound vesicles called melanosomes. Black, dark brown, and grey colours are produced by eumelanin, and reddish-brown colours are produced by phaeomelanin. Specific morphotypes and nanostructural arrangements of melanosomes and their relation to the keratin matrix in integumentary appendages create the so-called 'structural colours'. Reconstruction of colour patterns in ancient animals has opened an exciting new avenue for studying their life, behaviour and ecology. Modern relationships between the shape, arrangement, and size of avian melanosomes, melanin chemistry, and feather colour have been applied to reconstruct the hues and colour patterns of isolated feathers and plumages of the dinosaurs Anchiornis, Sinosauropteryx, and Microraptor in seminal papers that initiated the field of palaeocolour reconstruction. Since then, further research has identified countershading camouflage patterns, and informed subsequent predictions on the ecology and behaviour of these extinct animals. However, palaeocolour reconstruction remains a nascent field, and current approaches have considerable potential for further refinement, standardisation, and expansion. This includes detailed study of non-melanic pigments that might be preserved in fossilised integuments. A common issue among existing palaeocolour studies is the lack of contextualisation of different lines of evidence and the wide variety of techniques currently employed. To that end, this review focused on fossil amniotes: (i) produces an overarching framework that appropriately reconstructs palaeocolour by accounting for the chemical signatures of various pigments, morphology and local arrangement of pigment-bearing vesicles, pigment concentration, macroscopic colour patterns, and taphonomy; (ii) provides background context for the evolution of colour-producing mechanisms; and (iii) encourages future efforts in palaeocolour reconstructions particularly of less-studied groups such as non-dinosaur archosaurs and non-archosaur amniotes.
Collapse
Affiliation(s)
- Arindam Roy
- Vertebrate Palaeontology Laboratory, Department of Earth SciencesThe University of Hong KongPokfulamHong Kong SARChina
| | - Michael Pittman
- Vertebrate Palaeontology Laboratory, Department of Earth SciencesThe University of Hong KongPokfulamHong Kong SARChina
| | - Evan T. Saitta
- Integrative Research Center, Section of Earth SciencesField Museum of Natural History1400 S. Lake Shore Drive, ChicagoIL60605U.S.A.
| | - Thomas G. Kaye
- Foundation for Scientific Advancement7023 Alhambra Drive, Sierra VistaAZ85650U.S.A.
| | - Xing Xu
- Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences142 Xizhimenwai Street.Beijing100044China
| |
Collapse
|
25
|
Mondal P, Schwinn K, Huix-Rotllant M. Impact of the redox state of flavin chromophores on the UV–vis spectra, redox and acidity constants and electron affinities. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112164] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
26
|
Luo Y, Liu YJ. Theoretical Insight into a Nonadiabatic Proton-Coupled Electron Transfer Mechanism of Reduced Flavin Oxygenation. J Phys Chem A 2019; 123:4354-4359. [PMID: 31058505 DOI: 10.1021/acs.jpca.9b02084] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxygenation of reduced flavin has been a fascinating research hotspot in flavin-dependent proteins because it plays an indispensable role in cellular metabolism and has potential applications in biocatalysis. This spin-forbidden reaction of high efficiency is far from being fully understood. Although investigation on the flavin chemistry has been going on for more than 60 years, there are few mechanistic explanations for the reaction of the singlet-reduced flavin with triplet oxygen. In this paper, the reaction between oxygen and the model of free reduced flavin (reduced lumiflavin anion) was studied by density functional and multireference calculations in detail. The results reveal that the reaction proceeds by an electronically nonadiabatic proton-coupled electron transfer mechanism. The intersystem crossing point has been captured.
Collapse
Affiliation(s)
- Yanling Luo
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , China
| | - Ya-Jun Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , China
| |
Collapse
|
27
|
Liu HY, Nguyen HD, Lin CC. Dynamic PEG-Peptide Hydrogels via Visible Light and FMN-Induced Tyrosine Dimerization. Adv Healthc Mater 2018; 7:e1800954. [PMID: 30369100 DOI: 10.1002/adhm.201800954] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/01/2018] [Indexed: 02/03/2023]
Abstract
Photoresponsive hydrogels have become invaluable 3D culture matrices for mimicking aspects of the extracellular matrix. Recent efforts have focused on using ultraviolet (UV) light exposure and multifunctional macromers to induce secondary hydrogel crosslinking and dynamic matrix stiffening in the presence of cells. This contribution reports the design of a novel yet simple dynamic poly(ethylene glycol)-peptide hydrogel system through flavin mononucleotide (FMN) induced di-tyrosine crosslinking. These di-tyrosine linkages effectively increase hydrogel crosslinking density and elastic modulus. In addition, the degree of stiffening in hydrogels at a fixed PEG macromer content can be readily tuned by controlling FMN concentration or the number of tyrosine residues built-in to the peptide linker. Furthermore, tyrosine-bearing pendant biochemical motifs can be spatial-temporally patterned in the hydrogel network via controlling light exposure through a photomask. The visible light and FMN-induced tyrosine dimerization process produces a cytocompatible and physiologically relevant degree of stiffening, as shown by changes of cell morphology and gene expression in pancreatic cancer and stromal cells. This new dynamic hydrogel scheme should be highly desirable for researchers seeking a photoresponsive hydrogel system without complicated chemical synthesis and secondary UV light irradiation.
Collapse
Affiliation(s)
- Hung-Yi Liu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Han D Nguyen
- Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Chien-Chi Lin
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
- Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| |
Collapse
|
28
|
An unusual diphosphatase from the PhnP family cleaves reactive FAD photoproducts. Biochem J 2018; 475:261-272. [PMID: 29229761 DOI: 10.1042/bcj20170817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/02/2017] [Accepted: 12/07/2017] [Indexed: 12/12/2022]
Abstract
Flavins are notoriously photolabile, but while the photoproducts derived from the iso-alloxazine ring are well known the other photoproducts are not. In the case of FAD, typically the main cellular flavin, the other photoproducts are predicted to include four- and five-carbon sugars linked to ADP. These FAD photoproducts were shown to be potent glycating agents, more so than ADP-ribose. Such toxic compounds would require disposal via an ADP-sugar diphosphatase or other route. Comparative analysis of bacterial genomes uncovered a candidate disposal gene that is chromosomally clustered with genes for FAD synthesis or transport and is predicted to encode a protein of the PhnP cyclic phosphodiesterase family. The representative PhnP family enzyme from Koribacter versatilis (here named Fpd, FAD photoproduct diphosphatase) was found to have high, Mn2+-dependent diphosphatase activity against FAD photoproducts, FAD, and ADP-ribose, but almost no phosphodiesterase activity against riboflavin 4',5'-cyclic phosphate, a chemical breakdown product of FAD. To provide a structural basis of the unique Fpd activity, the crystal structure of K. versatilis Fpd was determined. The results place Fpd in the broad metallo-β-lactamase-like family of hydrolases, a diverse family commonly using two metals for hydrolytic catalysis. The active site of Fpd contains two Mn2+ ions and a bound phosphate, consistent with a diphosphatase mechanism. Our results characterize the first PhnP family member that is a diphosphatase rather than a cyclic phosphodiesterase and suggest its involvement in a cellular damage-control system that efficiently hydrolyzes the reactive, ADP-ribose-like products of FAD photodegradation.
Collapse
|
29
|
Bodvard K, Peeters K, Roger F, Romanov N, Igbaria A, Welkenhuysen N, Palais G, Reiter W, Toledano MB, Käll M, Molin M. Light-sensing via hydrogen peroxide and a peroxiredoxin. Nat Commun 2017; 8:14791. [PMID: 28337980 PMCID: PMC5376668 DOI: 10.1038/ncomms14791] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 01/27/2017] [Indexed: 02/08/2023] Open
Abstract
Yeast lacks dedicated photoreceptors; however, blue light still causes pronounced oscillations of the transcription factor Msn2 into and out of the nucleus. Here we show that this poorly understood phenomenon is initiated by a peroxisomal oxidase, which converts light into a hydrogen peroxide (H2O2) signal that is sensed by the peroxiredoxin Tsa1 and transduced to thioredoxin, to counteract PKA-dependent Msn2 phosphorylation. Upon H2O2, the nuclear retention of PKA catalytic subunits, which contributes to delayed Msn2 nuclear concentration, is antagonized in a Tsa1-dependent manner. Conversely, peroxiredoxin hyperoxidation interrupts the H2O2 signal and drives Msn2 oscillations by superimposing on PKA feedback regulation. Our data identify a mechanism by which light could be sensed in all cells lacking dedicated photoreceptors. In particular, the use of H2O2 as a second messenger in signalling is common to Msn2 oscillations and to light-induced entrainment of circadian rhythms and suggests conserved roles for peroxiredoxins in endogenous rhythms. While yeasts lack dedicated photoreceptors, they nonetheless possess metabolic rhythms responsive to light. Here the authors find that light signalling in budding yeast involves the production of H2O2, which in turn regulates protein kinase A through a peroxiredoxin-thioredoxin redox relay.
Collapse
Affiliation(s)
- Kristofer Bodvard
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden.,Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Ken Peeters
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
| | - Friederike Roger
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
| | - Natalie Romanov
- Mass Spectrometry Facility, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Aeid Igbaria
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Niek Welkenhuysen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden.,Hohmann Lab, Department of Biology and Biological Engineering, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Gaël Palais
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Wolfgang Reiter
- Department of Biochemistry, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Michel B Toledano
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Mikael Käll
- Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
| |
Collapse
|
30
|
Landry AP, Wang Y, Cheng Z, Crochet RB, Lee YH, Ding H. Flavin nucleotides act as electron shuttles mediating reduction of the [2Fe-2S] clusters in mitochondrial outer membrane protein mitoNEET. Free Radic Biol Med 2017; 102:240-247. [PMID: 27923678 PMCID: PMC5209285 DOI: 10.1016/j.freeradbiomed.2016.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/18/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
Abstract
MitoNEET, a primary target of type II diabetes drug pioglitazone, has an essential role in regulating energy metabolism, iron homeostasis, and production of reactive oxygen species in mitochondria. Structurally, mitoNEET is anchored to the mitochondrial outer membrane via its N-terminal transmembrane α-helix. The C-terminal cytosolic domain of mitoNEET hosts a redox active [2Fe-2S] cluster via three cysteine and one histidine residues. Here we report that the reduced flavin nucleotides can rapidly reduce the mitoNEET [2Fe-2S] clusters under anaerobic or aerobic conditions. In the presence of NADH and flavin reductase, 1 molecule of flavin nucleotide is sufficient to reduce about 100 molecules of the mitoNEET [2Fe-2S] clusters in 4min under aerobic conditions. The electron paramagnetic resonance (EPR) measurements show that flavin mononucleotide (FMN), but not flavin adenine dinucleotide (FAD), has a specific interaction with mitoNEET. Molecular docking models further reveal that flavin mononucleotide binds mitoNEET at the region between the N-terminal transmembrane α-helix and the [2Fe-2S] cluster binding domain. The closest distance between the [2Fe-2S] cluster and the bound flavin mononucleotide in mitoNEET is about 10Å, which could facilitate rapid electron transfer from the reduced flavin nucleotide to the [2Fe-2S] cluster in mitoNEET. The results suggest that flavin nucleotides may act as electron shuttles to reduce the mitoNEET [2Fe-2S] clusters and regulate mitochondrial functions in human cells.
Collapse
Affiliation(s)
- Aaron P Landry
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Yiming Wang
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Zishuo Cheng
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Robert B Crochet
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Yong-Hwan Lee
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Huangen Ding
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
| |
Collapse
|
31
|
Abstract
Riboflavin derivatives are essential cofactors for a myriad of flavoproteins. In bacteria, flavins importance extends beyond their role as intracellular protein cofactors, as secreted flavins are a key metabolite in a variety of physiological processes. Bacteria obtain riboflavin through the endogenous riboflavin biosynthetic pathway (RBP) or by the use of importer proteins. Bacteria frequently encode multiple paralogs of the RBP enzymes and as for other micronutrient supply pathways, biosynthesis and uptake functions largely coexist. It is proposed that bacteria shut down biosynthesis and would rather uptake riboflavin when the vitamin is environmentally available. Recently, the overlap of riboflavin provisioning elements has gained attention and the functions of duplicated paralogs of RBP enzymes started to be addressed. Results point towards the existence of a modular structure in the bacterial riboflavin supply pathways. Such structure uses subsets of RBP genes to supply riboflavin for specific functions. Given the importance of riboflavin in intra and extracellular bacterial physiology, this complex array of riboflavin provision pathways may have developed to contend with the various riboflavin requirements. In riboflavin-prototrophic bacteria, riboflavin transporters could represent a module for riboflavin provision for particular, yet unidentified processes, rather than substituting for the RBP as usually assumed.
Collapse
Affiliation(s)
- Víctor Antonio García-Angulo
- a Microbiology and Mycology Program, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| |
Collapse
|
32
|
Zhang M, Zou Y, Zhang F, Zhang X, Wang M. Efficacy of Blue-Light Cross-linking on Human Scleral Reinforcement. Optom Vis Sci 2015; 92:873-8. [PMID: 26099056 DOI: 10.1097/opx.0000000000000642] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To evaluate the biomechanical effects of collagen cross-linking by riboflavin/blue light (460 nm) on human sclera. METHODS Forty-two sclera samples from donated human eyes were treated with riboflavin at 0.5% on the equatorial sclera for 20 minutes and then randomly divided into seven groups and irradiated, respectively, with blue light at different intensities (14.6, 19.5, 22.5, 26, 32.5, and 40.6 mW/cm) for 20 minutes using a light-emitting diode source with an exposure area of 10 mm in diameter. The untreated samples constituted the control group. During irradiation, continuous riboflavin solution infiltration was carried out for 20 minutes. Stress-strain measurements of scleral strips were performed with a biomaterial tester. Stress data and Young modulus values in different groups were compared by one-way analysis of variance. RESULTS Blue-light (460 nm) cross-linking was efficient in stiffening human sclera strips. Interestingly, eyes treated with 22.5 mW/cm exhibited higher Young modulus values (19.12 [±4.88] MPa) at 8% strain compared with other groups, representing a 307.68% increase over control eye values (4.69 [±1.26] MPa). Stress and Young modulus increased gradually with irradiation intensity from 19.5 to 22.5 mW/cm before decreasing for higher intensities. CONCLUSIONS The biomechanical strength of human sclera may be enhanced by collagen cross-linking with riboflavin/460 nm blue-light irradiation; the dose of 22.5 mW/cm might be used for blue-light (460 nm) scleral cross-linking to achieve a higher efficacy.
Collapse
Affiliation(s)
- Miao Zhang
- *MD †MD, PhD Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (all authors)
| | | | | | | | | |
Collapse
|
33
|
Sena FV, Batista AP, Catarino T, Brito JA, Archer M, Viertler M, Madl T, Cabrita EJ, Pereira MM. Type-II NADH:quinone oxidoreductase from Staphylococcus aureus has two distinct binding sites and is rate limited by quinone reduction. Mol Microbiol 2015; 98:272-88. [PMID: 26172206 DOI: 10.1111/mmi.13120] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 01/02/2023]
Abstract
A prerequisite for any rational drug design strategy is understanding the mode of protein-ligand interaction. This motivated us to explore protein-substrate interaction in Type-II NADH:quinone oxidoreductase (NDH-2) from Staphylococcus aureus, a worldwide problem in clinical medicine due to its multiple drug resistant forms. NDHs-2 are involved in respiratory chains and recognized as suitable targets for novel antimicrobial therapies, as these are the only enzymes with NADH:quinone oxidoreductase activity expressed in many pathogenic organisms. We obtained crystal and solution structures of NDH-2 from S. aureus, showing that it is a dimer in solution. We report fast kinetic analyses of the protein and detected a charge-transfer complex formed between NAD(+) and the reduced flavin, which is dissociated by the quinone. We observed that the quinone reduction is the rate limiting step and also the only half-reaction affected by the presence of HQNO, an inhibitor. We analyzed protein-substrate interactions by fluorescence and STD-NMR spectroscopies, which indicate that NADH and the quinone bind to different sites. In summary, our combined results show the presence of distinct binding sites for the two substrates, identified quinone reduction as the rate limiting step and indicate the establishment of a NAD(+)-protein complex, which is released by the quinone.
Collapse
Affiliation(s)
- Filipa V Sena
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Ana P Batista
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Teresa Catarino
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - José A Brito
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Margarida Archer
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Martin Viertler
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry Technische Universität München, Lichtenbergstr.4, 85747, Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München Neuherberg and Biomolecular NMR- Spectroscopy, Medical University of Graz, 8010, Graz, Austria.,Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010, Graz, Austria
| | - Tobias Madl
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry Technische Universität München, Lichtenbergstr.4, 85747, Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München Neuherberg and Biomolecular NMR- Spectroscopy, Medical University of Graz, 8010, Graz, Austria.,Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010, Graz, Austria
| | - Eurico J Cabrita
- REQUIMTE, UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| |
Collapse
|
34
|
Randleman JB, Khandelwal SS, Hafezi F. Corneal cross-linking. Surv Ophthalmol 2015; 60:509-23. [PMID: 25980780 DOI: 10.1016/j.survophthal.2015.04.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 12/26/2022]
Abstract
Since its inception in the late 1990s, corneal cross-linking has grown from an interesting concept to a primary treatment for corneal ectatic disease worldwide. Using a combination of ultraviolet-A light and a chromophore (vitamin B2, riboflavin), the cornea can be stiffened, usually with a single application, and progressive thinning diseases such as keratoconus arrested. Despite being in clinical use for many years, some of the underlying processes, such as the role of oxygen and the optimal treatment times, are still being worked out. More than a treatment technique, corneal cross-links represent a physiological principle of connective tissue, which may explain the enormous versatility of the method. We highlight the history of corneal cross-linking, the scientific underpinnings of current techniques, evolving clinical treatment parameters, and the use of cross-linking in combination with refractive surgery and for the treatment of infectious keratitis.
Collapse
Affiliation(s)
- J Bradley Randleman
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA; Emory Vision, Emory Eye Center, Atlanta, Georgia, USA.
| | | | - Farhad Hafezi
- ELZA Institute, Zurich, Switzerland; Laboratory for Ocular Cell Biology, University of Geneva, Geneva, Switzerland; Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; Center for Applied Biotechnology and Molecular Medicine (CABMM), University of Zurich, Zurich, Switzerland
| |
Collapse
|
35
|
|