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Ayyari N, Vaezi Z, Ashin ZF, Karimi E, Mohsenzadeh Haji F, Nikkhah M, Naderi-Manesh H. Porphysome Engineered With Specific Protein Binding Sites as a Multimodal Theranostic Nanocarrier for Targeted Protein Delivery. Chem Biodivers 2024:e202400348. [PMID: 38616166 DOI: 10.1002/cbdv.202400348] [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: 02/07/2024] [Revised: 03/26/2024] [Accepted: 04/05/2024] [Indexed: 04/16/2024]
Abstract
The immobilization of proteins on the surface of carriers is challenging due to the loss of protein structure and function in this process. Here, we report the development of the protein immobilization on the surface of the metallated-porphyrin complex in the porphysome nanocarrier. The conjugated Ni-porphyrin to fatty acid (as a tail) has been synthesized and independently placed at the depth of the bilayer center of Dipalmitoylphosphatidylcholine (DPPC) in which the Ni-porphyrin was at the polar region of the membrane and is thus superficial. This porphysome (DPPC: Ni-porphyrin, 4 : 1 mole ratio) was formed by supramolecular self-assembly with a diameter of 173±7 nm and zeta potential -8.5±3.4 mv, which exhibited no significant toxicity at the experimental concentrations and acceptable cellular uptake on MCF-7 cells. The physicochemical properties and specific protein binding sites of the firefly luciferase as a model protein into the porphysome (1 : 2 mole ratio) show the conjugation efficiency about 80 % and the conformation of protein was completely maintained. Furthermore, bioluminescence assay and SDS-PAGE confirmed the preservation of protein function. The stabilized platform of porphyrin-lipid structure can potentially improve the efficacy of protein functionality for a particular display, shifting porphysomes from a simple carrier to a therapeutic agent.
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Affiliation(s)
- Niloofar Ayyari
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, PO Box, 14115-154, Tehran, Iran
| | - Zahra Vaezi
- Department of Bioactive compounds, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Postal codes, 14115-154, Tehran, Iran
| | - Zeinab Fotouhi Ashin
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, PO Box, 14115-154, Tehran, Iran
| | - Elham Karimi
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, PO Box, 14115-154, Tehran, Iran
| | - Fatemeh Mohsenzadeh Haji
- Department of Organic chemistry, Faculty of Chemistry, Tarbiat Modares University, Postal codes, 14115-154, Tehran, Iran
| | - Maryam Nikkhah
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, PO Box, 14115-154, Tehran, Iran
| | - Hossein Naderi-Manesh
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, PO Box, 14115-154, Tehran, Iran
- Department of Bioactive compounds, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Postal codes, 14115-154, Tehran, Iran
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2
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Olczak T, Śmiga M, Antonyuk SV, Smalley JW. Hemophore-like proteins of the HmuY family in the oral and gut microbiome: unraveling the mystery of their evolution. Microbiol Mol Biol Rev 2024; 88:e0013123. [PMID: 38305743 PMCID: PMC10966948 DOI: 10.1128/mmbr.00131-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024] Open
Abstract
SUMMARY Heme (iron protoporphyrin IX, FePPIX) is the main source of iron and PPIX for host-associated pathogenic bacteria, including members of the Bacteroidota (formerly Bacteroidetes) phylum. Porphyromonas gingivalis, a keystone oral pathogen, uses a unique heme uptake (Hmu) system, comprising a hemophore-like protein, designated as the first member of the novel HmuY family. Compared to classical, secreted hemophores utilized by Gram-negative bacteria or near-iron transporter domain-based hemophores utilized by Gram-positive bacteria, the HmuY family comprises structurally similar proteins that have undergone diversification during evolution. The best characterized are P. gingivalis HmuY and its homologs from Tannerella forsythia (Tfo), Prevotella intermedia (PinO and PinA), Bacteroides vulgatus (Bvu), and Bacteroides fragilis (BfrA, BfrB, and BfrC). In contrast to the two histidine residues coordinating heme iron in P. gingivalis HmuY, Tfo, PinO, PinA, Bvu, and BfrA preferentially use two methionine residues. Interestingly, BfrB, despite conserved methionine residue, binds the PPIX ring without iron coordination. BfrC binds neither heme nor PPIX in keeping with the lack of conserved histidine or methionine residues used by other members of the HmuY family. HmuY competes for heme binding and heme sequestration from host hemoproteins with other members of the HmuY family to increase P. gingivalis competitiveness. The participation of HmuY in the host immune response confirms its relevance in relation to the survival of P. gingivalis and its ability to induce dysbiosis not only in the oral microbiome but also in the gut microbiome or other host niches, leading to local injuries and involvement in comorbidities.
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Affiliation(s)
- Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Svetlana V. Antonyuk
- Molecular Biophysics Group, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, the University of Liverpool, Liverpool, United Kingdom
| | - John W. Smalley
- Institute of Life Course and Medical Sciences, School of Dentistry, the University of Liverpool, Liverpool, United Kingdom
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3
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Liu S, Butler CA, Ayton S, Reynolds EC, Dashper SG. Porphyromonas gingivalis and the pathogenesis of Alzheimer's disease. Crit Rev Microbiol 2024; 50:127-137. [PMID: 36597758 DOI: 10.1080/1040841x.2022.2163613] [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: 08/17/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 01/05/2023]
Abstract
The cause of Alzheimer's disease (AD), and the pathophysiological mechanisms involved, remain major unanswered questions in medical science. Oral bacteria, especially those species associated with chronic periodontitis and particularly Porphyromonas gingivalis, are being linked causally to AD pathophysiology in a subpopulation of susceptible individuals. P. gingivalis produces large amounts of proteolytic enzymes, haem and iron capture proteins, adhesins and internalins that are secreted and attached to the cell surface and concentrated onto outer membrane vesicles (OMVs). These enzymes and adhesive proteins have been shown to cause host tissue damage and stimulate inflammatory responses. The ecological and pathophysiological roles of P. gingivalis OMVs, their ability to disperse widely throughout the host and deliver functional proteins lead to the proposal that they may be the link between a P. gingivalis focal infection in the subgingivae during periodontitis and neurodegeneration in AD. P. gingivalis OMVs can cross the blood brain barrier and may accelerate AD-specific neuropathology by increasing neuroinflammation, plaque/tangle formation and dysregulation of iron homeostasis, thereby inducing ferroptosis leading to neuronal death and neurodegeneration.
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Affiliation(s)
- Sixin Liu
- School of Dentistry, University of Michigan, Ann Arbor, United States of America
| | - Catherine A Butler
- Centre for Oral Health Research, Melbourne Dental School, Bio21 Institute, The University of Melbourne, Parkville, Australia
| | - Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Eric C Reynolds
- Centre for Oral Health Research, Melbourne Dental School, Bio21 Institute, The University of Melbourne, Parkville, Australia
| | - Stuart G Dashper
- Centre for Oral Health Research, Melbourne Dental School, Bio21 Institute, The University of Melbourne, Parkville, Australia
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4
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Boutrin MC, Mishra A, Wang C, Dou Y, Fletcher HM. The involvement of CdhR in Porphyromonas gingivalis during nitric oxide stress. Mol Oral Microbiol 2023; 38:289-308. [PMID: 37134265 PMCID: PMC11018363 DOI: 10.1111/omi.12414] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 05/05/2023]
Abstract
Porphyromonas gingivalis, the causative agent of adult periodontitis, must gain resistance to frequent oxidative and nitric oxide (NO) stress attacks from immune cells in the periodontal pocket to survive. Previously, we found that, in the wild-type and under NO stress, the expression of PG1237 (CdhR), the gene encoding for a putative LuxR transcriptional regulator previously called community development and hemin regulator (CdhR), was upregulated 7.7-fold, and its adjacent gene PG1236 11.9-fold. Isogenic mutants P. gingivalis FLL457 (ΔCdhR::ermF), FLL458 (ΔPG1236::ermF), and FLL459 (ΔPG1236-CdhR::ermF) were made by allelic exchange mutagenesis to determine the involvement of these genes in P. gingivalis W83 NO stress resistance. The mutants were black pigmented and β hemolytic and their gingipain activities varied with strains. FLL457 and FLL459 mutants were more sensitive to NO compared to the wild type, and complementation restored NO sensitivity to that of the wild type. DNA microarray analysis of FLL457 showed that approximately 2% of the genes were upregulated and over 1% of the genes downregulated under NO stress conditions compared to the wild type. Transcriptome analysis of FLL458 and FLL459 under NO stress showed differences in their modulation patterns. Some similarities were also noticed between all mutants. The PG1236-CdhR gene cluster revealed increased expression under NO stress and may be part of the same transcriptional unit. Recombinant CdhR showed binding activity to the predicted promoter regions of PG1459 and PG0495. Taken together, the data indicate that CdhR may play a role in NO stress resistance and be involved in a regulatory network in P. gingivalis.
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Affiliation(s)
- Marie-Claire Boutrin
- Department of Biological Sciences, School of Arts and Sciences, Oakwood University, Huntsville, Alabama, USA
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, USA
| | - Arunima Mishra
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, USA
| | - Charles Wang
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, USA
| | - Yuetan Dou
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, USA
| | - Hansel M. Fletcher
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, USA
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Castillo O, Mancillas J, Hughes W, Brancaleon L. Characterization of the interaction of metal-protoporphyrins photosensitizers with β- lactoglobulin. Biophys Chem 2023; 292:106918. [PMID: 36399946 DOI: 10.1016/j.bpc.2022.106918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/24/2022] [Accepted: 10/27/2022] [Indexed: 11/17/2022]
Abstract
We investigated the interaction of a series of metal-protoporphyrins (PPIXs) with bovine β- lactoglobulin (BLG) using a combination of optical spectroscopy and computational simulations. Unlike other studies, the simulations were not merely used to rationalize the experimental data but were employed to refine the experimental data itself. The study was carried out at two pH values, 5 and 9, where BLG is known to have different conformation dictated by the so-called Tanford transition which occurs near pH 7.5. The transition is postulated to regulate access to the interior binding cavity of the protein, thus the pH variation was used as a parameter to investigate whether PPIXs access the central cavity of BLG. The results of our study show that indeed binding increases significantly at alkaline pH, however, the increased affinity is not due to the accessibility of the central cavity. Instead, binding appears to be determined by the tendency of PPIXs to form large inhomogeneous aggregates at acidic pH which hinders interactions with proteins. The binding site determined through a combination of experimental and computational methods is located at the interface between two BLG monomers where the long α-helix segment of the protein face each other. This region is rich in positively charged Lys residues that interact with the propionic acid chains of the protoporphyrins. Establishing the modality of binding between protoporphyrins and BLG would have important consequences for the use of BLG:PPIX complexes in applications such as artificial photoreceptors, artificial metallo-enzymes, delivery of photosensitizers for phototherapy and even solar energy conversion.
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Affiliation(s)
- Omar Castillo
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - James Mancillas
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - William Hughes
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Lorenzo Brancaleon
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA.
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Donegan RK, Fu Y, Copeland J, Idga S, Brown G, Hale OF, Mitra A, Yang H, Dailey HA, Niederweis M, Jain P, Reddi AR. Exogenously Scavenged and Endogenously Synthesized Heme Are Differentially Utilized by Mycobacterium tuberculosis. Microbiol Spectr 2022; 10:e0360422. [PMID: 36169423 PMCID: PMC9604157 DOI: 10.1128/spectrum.03604-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 01/12/2023] Open
Abstract
Heme is both an essential cofactor and an abundant source of nutritional iron for the human pathogen Mycobacterium tuberculosis. While heme is required for M. tuberculosis survival and virulence, it is also potentially cytotoxic. Since M. tuberculosis can both synthesize and take up heme, the de novo synthesis of heme and its acquisition from the host may need to be coordinated in order to mitigate heme toxicity. However, the mechanisms employed by M. tuberculosis to regulate heme uptake, synthesis, and bioavailability are poorly understood. By integrating ratiometric heme sensors with mycobacterial genetics, cell biology, and biochemistry, we determined that de novo-synthesized heme is more bioavailable than exogenously scavenged heme, and heme availability signals the downregulation of heme biosynthetic enzyme gene expression. Ablation of heme synthesis does not result in the upregulation of known heme import proteins. Moreover, we found that de novo heme synthesis is critical for survival from macrophage assault. Altogether, our data suggest that mycobacteria utilize heme from endogenous and exogenous sources differently and that targeting heme synthesis may be an effective therapeutic strategy to treat mycobacterial infections. IMPORTANCE Mycobacterium tuberculosis infects ~25% of the world's population and causes tuberculosis (TB), the second leading cause of death from infectious disease. Heme is an essential metabolite for M. tuberculosis, and targeting the unique heme biosynthetic pathway of M. tuberculosis could serve as an effective therapeutic strategy. However, since M. tuberculosis can both synthesize and scavenge heme, it was unclear if inhibiting heme synthesis alone could serve as a viable approach to suppress M. tuberculosis growth and virulence. The importance of this work lies in the development and application of genetically encoded fluorescent heme sensors to probe bioavailable heme in M. tuberculosis and the discovery that endogenously synthesized heme is more bioavailable than exogenously scavenged heme. Moreover, it was found that heme synthesis protected M. tuberculosis from macrophage killing, and bioavailable heme in M. tuberculosis is diminished during macrophage infection. Altogether, these findings suggest that targeting M. tuberculosis heme synthesis is an effective approach to combat M. tuberculosis infections.
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Affiliation(s)
- Rebecca K. Donegan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Chemistry, Barnard College, New York, New York, USA
| | - Yibo Fu
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jacqueline Copeland
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Stanzin Idga
- Department of Pathology, Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, New York, USA
| | - Gabriel Brown
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Owen F. Hale
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Avishek Mitra
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Hui Yang
- Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Harry A. Dailey
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Paras Jain
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Cell Therapy and Cell Engineering Laboratory, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Amit R. Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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7
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Opdam LV, Polanco EA, de Regt B, Lambertina N, Bakker C, Bonnet S, Pandit A. A screening method for binding synthetic metallo-complexes to haem proteins. Anal Biochem 2022; 653:114788. [PMID: 35732212 DOI: 10.1016/j.ab.2022.114788] [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: 02/16/2022] [Revised: 06/08/2022] [Accepted: 06/11/2022] [Indexed: 11/17/2022]
Abstract
The introduction of a second coordination sphere, in the form of a protein scaffold, to synthetic catalysts can be beneficial for their reactivity and substrate selectivity. Here we present semi-native polyacrylamide gel electrophoresis (semi-native PAGE) as a rapid screening method for studying metal complex-protein interactions. Such a screening is generally performed using electron spray ionization mass spectrometry (ESI-MS) and/or UV-Vis spectroscopy. Semi-native PAGE analysis has the advantage that it does not rely on spectral changes of the metal complex upon protein interaction and can be applied for high-throughput screening and optimization of complex binding. In semi-native PAGE non-denatured protein samples are loaded on a gel containing sodium dodecyl sulphate (SDS), leading to separation based on differences in structural stability. Semi-native PAGE gel runs of catalyst-protein mixtures were compared to gel runs obtained with native and denaturing PAGE. ESI-MS was additionally realised to confirm protein-complex binding. The general applicability of semi-native PAGE was investigated by screening the binding of various cobalt- and ruthenium-based compounds to three types of haem proteins.
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Affiliation(s)
- Laura V Opdam
- SSNMR/BPOC, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Ehider A Polanco
- MCBIM Departments, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Boyd de Regt
- SSNMR/BPOC, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | | | - Cas Bakker
- SSNMR/BPOC, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Sylvestre Bonnet
- MCBIM Departments, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Anjali Pandit
- SSNMR/BPOC, Einsteinweg 55, 2333 CC, Leiden, the Netherlands.
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8
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Kosno J, Siemińska K, Olczak T. Unique Properties of Heme Binding of the Porphyromonas gingivalis HmuY Hemophore-like Protein Result from the Evolutionary Adaptation of the Protein Structure. Molecules 2022; 27:molecules27051703. [PMID: 35268804 PMCID: PMC8911585 DOI: 10.3390/molecules27051703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 12/04/2022] Open
Abstract
To acquire heme, Porphyromonas gingivalis uses a hemophore-like protein (HmuY). HmuY sequesters heme from host hemoproteins or heme-binding proteins produced by cohabiting bacteria, and delivers it to the TonB-dependent outer-membrane receptor (HmuR). Although three-dimensional protein structures of members of the novel HmuY family are overall similar, significant differences exist in their heme-binding pockets. Histidines (H134 and H166) coordinating the heme iron in P. gingivalis HmuY are unique and poorly conserved in the majority of its homologs, which utilize methionines. To examine whether changes observed in the evolution of these proteins in the Bacteroidetes phylum might result in improved heme binding ability of HmuY over its homologs, we substituted histidine residues with methionine residues. Compared to the native HmuY, site-directed mutagenesis variants bound Fe(III)heme with lower ability in a similar manner to Bacteroides vulgatus Bvu and Tannerella forsythia Tfo. However, a mixed histidine-methionine couple in the HmuY was sufficient to bind Fe(II)heme, similarly to T. forsythia Tfo, Prevotella intermedia PinO and PinA. Double substitution resulted in abolished heme binding. The structure of HmuY heme-binding pocket may have been subjected to evolution, allowing for P. gingivalis to gain an advantage in heme acquisition regardless of environmental redox conditions.
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9
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Sławski J, Białek R, Burdziński G, Gibasiewicz K, Worch R, Grzyb J. Competition between Photoinduced Electron Transfer and Resonance Energy Transfer in an Example of Substituted Cytochrome c-Quantum Dot Systems. J Phys Chem B 2021; 125:3307-3320. [PMID: 33760623 PMCID: PMC8041302 DOI: 10.1021/acs.jpcb.1c00325] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Colloidal quantum
dots (QDs) are nanoparticles that are able to
photoreduce redox proteins by electron transfer (ET). QDs are also
able to transfer energy by resonance energy transfer (RET). Here,
we address the question of the competition between these two routes
of QDs’ excitation quenching, using cadmium telluride QDs and
cytochrome c (CytC) or its metal-substituted derivatives. We used
both oxidized and reduced versions of native CytC, as well as fluorescent,
nonreducible Zn(II)CytC, Sn(II)CytC, and metal-free porphyrin CytC.
We found that all of the CytC versions quench QD fluorescence, although
the interaction may be described differently in terms of static and
dynamic quenching. QDs may be quenchers of fluorescent CytC derivatives,
with significant differences in effectiveness depending on QD size.
SnCytC and porphyrin CytC increased the rate of Fe(III)CytC photoreduction,
and Fe(II)CytC slightly decreased the rate and ZnCytC presence significantly
decreased the rate and final level of reduced FeCytC. These might
be partially explained by the tendency to form a stable complex between
protein and QDs, which promoted RET and collisional quenching. Our
findings show that there is a net preference for photoinduced ET over
other ways of energy transfer, at least partially, due to a lack of
donors, regenerating a hole at QDs and leading to irreversibility
of ET events. There may also be a common part of pathways leading
to photoinduced ET and RET. The nature of synergistic action observed
in some cases allows the hypothesis that RET may be an additional
way to power up the ET.
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Affiliation(s)
- Jakub Sławski
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Rafał Białek
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Gotard Burdziński
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Krzysztof Gibasiewicz
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Remigiusz Worch
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Joanna Grzyb
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland
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10
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Sitte E, Senge MO. The Red Color of Life Transformed - Synthetic Advances and Emerging Applications of Protoporphyrin IX in Chemical Biology. European J Org Chem 2020; 2020:3171-3191. [PMID: 32612451 PMCID: PMC7319466 DOI: 10.1002/ejoc.202000074] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Indexed: 01/10/2023]
Abstract
Protoporphyrin IX (PPIX) is the porphyrin scaffold of heme b, a ubiquitous prosthetic group of proteins responsible for oxygen binding (hemoglobin, myoglobin), electron transfer (cytochrome c) and catalysis (cytochrome P450, catalases, peroxidases). PPIX and its metallated derivatives frequently find application as therapeutic agents, imaging tools, catalysts, sensors and in light harvesting. The vast toolkit of accessible porphyrin functionalization reactions enables easy synthetic modification of PPIX to meet the requirements for its multiple uses. In the past few years, particular interest has arisen in exploiting the interaction of PPIX and its synthetic derivatives with biomolecules such as DNA and heme-binding proteins to evolve molecular devices with new functions as well as to uncover potential therapeutic toeholds. This review strives to shine a light on the most recent developments in the synthetic chemistry of PPIX and its uses in selected fields of chemical biology.
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Affiliation(s)
- Elisabeth Sitte
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse Street2DublinIreland
| | - Mathias O. Senge
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse Street2DublinIreland
- Institute for Advanced Study (TUM‐IAS)Technische Universität MünchenLichtenberg‐Str. 2a85748GarchingGermany
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11
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Novel combinations of experimental and computational analysis tested on the binding of metalloprotoporphyrins to albumin. Int J Biol Macromol 2019; 134:445-457. [PMID: 31078597 DOI: 10.1016/j.ijbiomac.2019.05.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/08/2019] [Accepted: 05/08/2019] [Indexed: 02/02/2023]
Abstract
The evidence that Human Serum Albumin (HSA) binds metal ions and organometallic compounds has generated interest in its physiological role as a metalloprotein and as a vehicle for synthetic biology applications (e.g., synthetic blood and solar energy conversion). HSA has been shown to bind metallo-porphyrins, however, the structural details of such interactions are available only for the HSA:heme complex. A typical challenge for studying the interaction of proteins with metalloporphyrins is the poor solubility of the ligands that affect the characterization the complexes. The manuscript shows that a combination of dialysis and centrifugation yields aqueous solutions that contain >90% HSA:porphyrin complexes and virtually eliminate aggregated ligands. The removal of aggregates increases the quality of the optical spectroscopy data which, in turn, yield more accurate binding constants (~0.1 and 2.1 × 106 M-1) and reveal FRET between Trp214 and the porphyrins. The Trp-porphyrin distance was estimated to be within the 28-34 Å range and was used to guide the search of binding sites through a novel feedback approach with docking simulations. Results suggest while some protoporphyrins (metal-free, Fe(III)PPIX and Mg(II)PPIX) bind HSA at the heme site, others (Zn(II)PPIX, Mn(III)PPIX and Sn(IV)PPIX) are more likely to bind the Cys34.
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Tannerella forsythia Tfo belongs to Porphyromonas gingivalis HmuY-like family of proteins but differs in heme-binding properties. Biosci Rep 2018; 38:BSR20181325. [PMID: 30266745 PMCID: PMC6200708 DOI: 10.1042/bsr20181325] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/10/2018] [Accepted: 09/20/2018] [Indexed: 12/16/2022] Open
Abstract
Porphyromonas gingivalis is considered the principal etiologic agent and keystone pathogen of chronic periodontitis. As an auxotrophic bacterium, it must acquire heme to survive and multiply at the infection site. P. gingivalis HmuY is the first member of a novel family of hemophore-like proteins. Bacterial heme-binding proteins usually use histidine-methionine or histidine-tyrosine residues to ligate heme-iron, whereas P. gingivalis HmuY uses two histidine residues. We hypothesized that other 'red complex' members, i.e. Tannerella forsythia and Treponema denticola might utilize similar heme uptake mechanisms to the P. gingivalis HmuY. Comparative and phylogenetic analyses suggested differentiation of HmuY homologs and low conservation of heme-coordinating histidine residues present in HmuY. The homologs were subjected to duplication before divergence of Bacteroidetes lineages, which could facilitate evolution of functional diversification. We found that T. denticola does not code an HmuY homolog. T. forsythia protein, termed as Tfo, binds heme, but preferentially in the ferrous form, and sequesters heme from the albumin-heme complex under reducing conditions. In agreement with that, the 3D structure of Tfo differs from that of HmuY in the folding of heme-binding pocket, containing two methionine residues instead of two histidine residues coordinating heme in HmuY. Heme binding to apo-HmuY is accompanied by movement of the loop carrying the His166 residue, closing the heme-binding pocket. Molecular dynamics simulations (MD) demonstrated that this conformational change also occurs in Tfo. In conclusion, our findings suggest that HmuY-like family might comprise proteins subjected during evolution to significant diversification, resulting in different heme-binding properties.
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Brewitz HH, Hagelueken G, Imhof D. Structural and functional diversity of transient heme binding to bacterial proteins. Biochim Biophys Acta Gen Subj 2017; 1861:683-697. [DOI: 10.1016/j.bbagen.2016.12.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/15/2016] [Accepted: 12/20/2016] [Indexed: 11/27/2022]
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Hu J, Allen R, Rozinek S, Brancaleon L. Experimental and computational characterization of photosensitized conformational effects mediated by protoporphyrin ligands on human serum albumin. Photochem Photobiol Sci 2017; 16:694-710. [DOI: 10.1039/c6pp00096g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Metal-free and Zn-chelated protoporphyrins were bound to human serum albumin. Their binding parameters and locations were characterized and the effect of their irradiation on the conformation of the protein was demonstrated.
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Affiliation(s)
- Jie Hu
- Department of Physics and Astronomy
- University of Texas at San Antonio
- 78249 San Antonio
- USA
| | - Ryan Allen
- Department of Physics and Astronomy
- University of Texas at San Antonio
- 78249 San Antonio
- USA
| | - Sarah Rozinek
- Department of Physics and Astronomy
- University of Texas at San Antonio
- 78249 San Antonio
- USA
| | - Lorenzo Brancaleon
- Department of Physics and Astronomy
- University of Texas at San Antonio
- 78249 San Antonio
- USA
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15
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Smalley JW, Olczak T. Heme acquisition mechanisms of Porphyromonas gingivalis - strategies used in a polymicrobial community in a heme-limited host environment. Mol Oral Microbiol 2016; 32:1-23. [PMID: 26662717 DOI: 10.1111/omi.12149] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2015] [Indexed: 01/14/2023]
Abstract
Porphyromonas gingivalis, a main etiologic agent and key pathogen responsible for initiation and progression of chronic periodontitis requires heme as a source of iron and protoporphyrin IX for its survival and the ability to establish an infection. Porphyromonas gingivalis is able to accumulate a defensive cell-surface heme-containing pigment in the form of μ-oxo bisheme. The main sources of heme for P. gingivalis in vivo are hemoproteins present in saliva, gingival crevicular fluid, and erythrocytes. To acquire heme, P. gingivalis uses several mechanisms. Among them, the best characterized are those employing hemagglutinins, hemolysins, and gingipains (Kgp, RgpA, RgpB), TonB-dependent outer-membrane receptors (HmuR, HusB, IhtA), and hemophore-like proteins (HmuY, HusA). Proteins involved in intracellular heme transport, storage, and processing are less well characterized (e.g. PgDps). Importantly, P. gingivalis may also use the heme acquisition systems of other bacteria to fulfill its own heme requirements. Porphyromonas gingivalis displays a novel paradigm for heme acquisition from hemoglobin, whereby the Fe(II)-containing oxyhemoglobin molecule must first be oxidized to methemoglobin to facilitate heme release. This process not only involves P. gingivalis arginine- and lysine-specific gingipains, but other proteases (e.g. interpain A from Prevotella intermedia) or pyocyanin produced by Pseudomonas aeruginosa. Porphyromonas gingivalis is then able to fully proteolyze the more susceptible methemoglobin substrate to release free heme or to wrest heme from it directly through the use of the HmuY hemophore.
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Affiliation(s)
- J W Smalley
- School of Dentistry, University of Liverpool, Liverpool, UK
| | - T Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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Zhang H, Pan J, Ghimire S, Bork MA, Riccitelli MM, McMillin DR, Choi JH. Regeneration of Light-Harvesting Complexes via Dynamic Replacement of Photodegraded Chromophores. ACS APPLIED MATERIALS & INTERFACES 2015; 7:7833-7837. [PMID: 25848806 DOI: 10.1021/acsami.5b01924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
All-synthetic molecular donor-acceptor complexes are designed, which are capable of counteracting the effect of photoinduced degradation of donor chromophores. Anionic gallium protoporphyrin IX (GaPP) and semiconducting carbon nanotube (CNT) are used as a model donor-acceptor complex, which is assembled using DNA oligonucleotides. The GaPP-DNA-CNT complex produces an anodic photocurrent in a photoelectrochemical cell, which steadily decays due to photo-oxidation. By modulating the chemical environment, we showed that the photodegraded chromophores may be dissociated from the complex, whereas the DNA-coated carbon nanotube acceptors are kept intact. Reassociation with fresh porphyrins leads to the full recovery of GaPP absorption and photocurrents. This strategy could form a basis for improving the light-harvesting performance of molecular donor-acceptor complexes and extending their operation lifetime.
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Affiliation(s)
- Hanyu Zhang
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jing Pan
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Srijana Ghimire
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Matthew A Bork
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Molly M Riccitelli
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - David R McMillin
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jong Hyun Choi
- †School of Mechanical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
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Śmiga M, Bielecki M, Olczak M, Smalley JW, Olczak T. Anti-HmuY antibodies specifically recognize Porphyromonas gingivalis HmuY protein but not homologous proteins in other periodontopathogens. PLoS One 2015; 10:e0117508. [PMID: 25658942 PMCID: PMC4320075 DOI: 10.1371/journal.pone.0117508] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 12/26/2014] [Indexed: 12/20/2022] Open
Abstract
Given the emerging evidence of an association between periodontal infections and systemic conditions, the search for specific methods to detect the presence of P. gingivalis, a principal etiologic agent in chronic periodontitis, is of high importance. The aim of this study was to characterize antibodies raised against purified P. gingivalis HmuY protein and selected epitopes of the HmuY molecule. Since other periodontopathogens produce homologs of HmuY, we also aimed to characterize responses of antibodies raised against the HmuY protein or its epitopes to the closest homologous proteins from Prevotella intermedia and Tannerella forsythia. Rabbits were immunized with purified HmuY protein or three synthetic, KLH-conjugated peptides, derived from the P. gingivalis HmuY protein. The reactivity of anti-HmuY antibodies with purified proteins or bacteria was determined using Western blotting and ELISA assay. First, we found homologs of P. gingivalis HmuY in P. intermedia (PinO and PinA proteins) and T. forsythia (Tfo protein) and identified corrected nucleotide and amino acid sequences of Tfo. All proteins were overexpressed in E. coli and purified using ion-exchange chromatography, hydrophobic chromatography and gel filtration. We demonstrated that antibodies raised against P. gingivalis HmuY are highly specific to purified HmuY protein and HmuY attached to P. gingivalis cells. No reactivity between P. intermedia and T. forsythia or between purified HmuY homologs from these bacteria and anti-HmuY antibodies was detected. The results obtained in this study demonstrate that P. gingivalis HmuY protein may serve as an antigen for specific determination of serum antibodies raised against this bacterium.
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Affiliation(s)
- Michał Śmiga
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, 14A F. Joliot-Curie St., 50-383 Wroclaw, Poland
| | - Marcin Bielecki
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, 14A F. Joliot-Curie St., 50-383 Wroclaw, Poland
| | - Mariusz Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, 14A F. Joliot-Curie St., 50-383 Wroclaw, Poland
| | - John W. Smalley
- School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom
| | - Teresa Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, 14A F. Joliot-Curie St., 50-383 Wroclaw, Poland
- * E-mail:
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Ciuraszkiewicz J, Śmiga M, Mackiewicz P, Gmiterek A, Bielecki M, Olczak M, Olczak T. Fur homolog regulatesPorphyromonas gingivalisvirulence under low-iron/heme conditions through a complex regulatory network. Mol Oral Microbiol 2014; 29:333-53. [DOI: 10.1111/omi.12077] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2014] [Indexed: 12/22/2022]
Affiliation(s)
- J. Ciuraszkiewicz
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - M. Śmiga
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - P. Mackiewicz
- Department of Genomics; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - A. Gmiterek
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - M. Bielecki
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - M. Olczak
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
| | - T. Olczak
- Laboratory of Biochemistry; Faculty of Biotechnology; University of Wroclaw; Wroclaw Poland
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Antibacterial properties of metal and metalloid ions in chronic periodontitis and peri-implantitis therapy. Acta Biomater 2014; 10:3795-810. [PMID: 24704700 DOI: 10.1016/j.actbio.2014.03.028] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 03/07/2014] [Accepted: 03/26/2014] [Indexed: 12/21/2022]
Abstract
Periodontal diseases like periodontitis and peri-implantitis have been linked with Gram-negative anaerobes. The incorporation of various chemotherapeutic agents, including metal ions, into several materials and devices has been extensively studied against periodontal bacteria, and materials doped with metal ions have been proposed for the treatment of periodontal and peri-implant diseases. The aim of this review is to discuss the effectiveness of materials doped with metal and metalloid ions already used in the treatment of periodontal diseases, as well as the potential use of alternative materials that are currently available for other applications but have been proved to be cytotoxic to the specific periodontal pathogens. The sources of this review included English articles using Google Scholar™, ScienceDirect, Scopus and PubMed. Search terms included the combinations of the descriptors "disease", "ionic species" and "bacterium". Articles that discuss the biocidal properties of materials doped with metal and metalloid ions against the specific periodontal bacteria were included. The articles were independently extracted by two authors using predefined data fields. The evaluation of resources was based on the quality of the content and the relevance to the topic, which was evaluated by the ionic species and the bacteria used in the study, while the final application was not considered as relevant. The present review summarizes the extensive previous and current research efforts concerning the use of metal ions in periodontal diseases therapy, while it points out the challenges and opportunities lying ahead.
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Minandri F, Bonchi C, Frangipani E, Imperi F, Visca P. Promises and failures of gallium as an antibacterial agent. Future Microbiol 2014; 9:379-97. [DOI: 10.2217/fmb.14.3] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Differential roles of tryptophan residues in conformational stability of Porphyromonas gingivalis HmuY hemophore. BMC BIOCHEMISTRY 2014; 15:2. [PMID: 24512694 PMCID: PMC3922309 DOI: 10.1186/1471-2091-15-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/03/2014] [Indexed: 12/05/2022]
Abstract
Background We have previously shown that the P. gingivalis HmuY hemophore-like protein binds heme and scavenges heme from host hemoproteins to further deliver it to the cognate heme receptor HmuR. The aim of this study was to characterize structural features of HmuY variants in the presence and absence of heme with respect to roles of tryptophan residues in conformational stability. Results HmuY possesses tryptophan residues at positions 51 and 73, which are conserved in HmuY homologs present in a variety of bacteria, and a tryptophan residue at position 161, which has been found only in HmuY identified in P. gingivalis strains. We expressed and purified the wildtype HmuY and its protein variants with single tryptophan residues replaced by alanine or tyrosine residues. All HmuY variants were subjected to thermal denaturation and fluorescence spectroscopy analyses. Replacement of the most buried W161 only moderately affects protein stability. The most profound effect of the lack of a large hydrophobic side chain in respect to thermal stability is observed for W73. Also replacement of the W51 exposed on the surface results in the greatest loss of protein stability and even the large aromatic side chain of a tyrosine residue has little potential to substitute this tryptophan residue. Heme binding leads to different exposure of the tryptophan residue at position 51 to the surface of the protein. Differences in structural stability of HmuY variants suggest the change of the tertiary structure of the protein upon heme binding. Conclusions Here we demonstrate differential roles of tryptophan residues in the protein conformational stability. We also propose different conformations of apo- and holoHmuY caused by tertiary changes which allow heme binding to the protein.
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Contreras H, Chim N, Credali A, Goulding CW. Heme uptake in bacterial pathogens. Curr Opin Chem Biol 2014; 19:34-41. [PMID: 24780277 DOI: 10.1016/j.cbpa.2013.12.014] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 12/12/2013] [Accepted: 12/12/2013] [Indexed: 11/30/2022]
Abstract
Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within the bacterial cytosol to liberate iron. The pathways for heme transport into the bacterial cytosol are divergent, harboring non-homologous protein sequences, novel structures, varying numbers of proteins, and different mechanisms. Congruously, the breakdown of heme within the bacterial cytosol by sequence-divergent proteins releases iron and distinct degradation products.
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Affiliation(s)
- Heidi Contreras
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Nicholas Chim
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Alfredo Credali
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Celia W Goulding
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA; Department of Pharmaceutical Sciences, UCI, Irvine, CA 92697, USA.
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