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Zhou Q, Li X, Zheng X, Zhang X, Jiang Y, Shen H. Metabolomics reveals the phytotoxicity mechanisms of foliar spinach exposed to bulk and nano sizes of PbCO 3. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133097. [PMID: 38113737 DOI: 10.1016/j.jhazmat.2023.133097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/14/2023] [Accepted: 11/23/2023] [Indexed: 12/21/2023]
Abstract
PbCO3 is an ancient raw material for Pb minerals and continues to pose potential risks to the environment and human health through mining and industrial processes. However, the specific effects of unintentional PbCO3 discharge on edible plants remain poorly understood. This study unravels how foliar application of PbCO3 induces phytotoxicity by potentially influencing leaf morphology, photosynthetic pigments, oxidative stress, and metabolic pathways related to energy regulation, cell damage, and antioxidant defense in Spinacia oleracea L. Additionally, it quantifies the resultant human health risks. Plants were foliarly exposed to PbCO3 nanoparticles (NPs) and bulk products (BPs), as well as Pb2+ at 0, 5, 10, 25, 50, and 100 mg·L-1 concentrations once a day for three weeks. The presence and localization of PbCO3 NPs inside the plant cells were confirmed by TEM-EDS analysis. The maximum accumulation of total Pb was recorded in the root (2947.77 mg·kg-1 DW for ion exposure), followed by the shoot (942.50 mg·kg-1 DW for NPs exposure). The results revealed that PbCO3 and Pb2+ exposure had size- and dose-dependent inhibitory effects on spinach length, biomass, and photosynthesis attributes, inducing impacts on the antioxidase activity of CAT, membrane permeability, and nutrient elements absorption and translocation. Pb2+ exhibited pronounced toxicity in morphology and chlorophyll; PbCO3 BP exposure accumulated the most lipid peroxidation products of MDA and H2O2; and PbCO3 NPs triggered the largest cell membrane damage. Furthermore, PbCO3 NPs at 10 and 100 mg·L-1 induced dose-dependent metabolic reprogramming in spinach leaves, disturbing the metabolic mechanisms related to amino acids, antioxidant defense, oxidative phosphorylation, fatty acid cycle, and the respiratory chain. The spinach showed a non-carcinogenic health risk hierarchy: Pb2+ > PbCO3 NPs > PbCO3 BPs, with children more vulnerable than adults. These findings enhance our understanding of PbCO3 particle effects on food security, emphasizing the need for further research to minimize their impact on human dietary health.
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Affiliation(s)
- Qishang Zhou
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China
| | - Xiaoping Li
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China; MRC Centre for Environment and Health, Environmental Research Group, School of Public Health, Imperial College London, 80 Wood Lane, London W12 0BZ, UK.
| | - Xueming Zheng
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China
| | - Xu Zhang
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China
| | - Yueheng Jiang
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China
| | - He Shen
- Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an, Shaanxi 710062, PR China; International Joint Research Centre of Shaanxi Province for Pollutant Exposure and Eco-environmental Health, Xi'an, Shaanxi 710062, PR China
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Javanshad R, Venter AR. Effects of amino acid additives on protein solubility - insights from desorption and direct electrospray ionization mass spectrometry. Analyst 2021; 146:6592-6604. [PMID: 34586125 DOI: 10.1039/d1an01392k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Naturally occurring amino acids have been broadly used as additives to improve protein solubility and inhibit aggregation. In this study, improvements in protein signal intensity obtained with the addition of L-serine, and structural analogs, to the desorption electrospray ionization mass spectrometry (DESI-MS) spray solvent were measured. The results were interpreted at the hand of proposed mechanisms of solution additive effects on protein solubility and dissolution. DESI-MS allows for these processes to be studied efficiently using dilute concentrations of additives and small amounts of proteins, advantages that represent real benefits compared to classical methods of studying protein stability and aggregation. We show that serine significantly increases the protein signal in DESI-MS when native proteins are undergoing unfolding during the dissolution process with an acidic solvent system (p-value = 0.0001), or with ammonium bicarbonate under denaturing conditions for proteins with high isoelectric points (p-value = 0.001). We establish that a similar increase in the protein signal cannot be observed with direct ESI-MS, and the observed increase is therefore not related to ionization processes or changes in the physical properties of the bulk solution. The importance of the presence of serine during protein conformational changes while undergoing dissolution is demonstrated through comparisons between the analyses of proteins deposited in native or unfolded states and by using native state-preserving and denaturing desorption solvents. We hypothesize that direct, non-covalent interactions involving all three functional groups of serine are involved in the beneficial effect on protein solubility and dissolution. Supporting evidence for a direct interaction include a reduction in efficacy with D-serine or the racemic mixture, indicating a non-bulk-solution physical property effect; insensitivity to the sample surface type or relative placement of serine addition; and a reduction in efficacy with any modifications to the serine structure, most notably the carboxyl functional group. An alternative hypothesis, also supported by some of our observations, could involve the role of serine clusters in the mechanism of solubility enhancement. Our study demonstrates the capability of DESI-MS together with complementary ESI-MS experiments as a novel tool for understanding protein solubility and dissolution and investigating the mechanism of action for solubility-enhancing additives.
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Affiliation(s)
- Roshan Javanshad
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA.
| | - Andre R Venter
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA.
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3
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Wu J, He S, Yu Z, Lan D, Xiong X, Li Z. Transcriptomic study of yak mammary gland tissue during lactation. Anim Biotechnol 2020; 33:672-679. [PMID: 32959729 DOI: 10.1080/10495398.2020.1823401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Yak milk, a high-quality milk, is one of the best raw materials for dairy products and economically important to pastoral herdsmen. To make a further understanding of the molecular differences in mammary tissues of the yaks with different milk production during lactation, in this study, we took the use of RNA-seq to perform high-throughput sequencing and analysis of the mammary gland transcriptomes of both high-yielding yak and low-yielding yaks during lactation. By the comparison and analysis of the transcriptome data for the mammary gland tissue of high-yielding yak and low-yield yak, 144 differential genes were screened out, of which 49 were upregulated and 95 were downregulated. Further functional analysis indicated that these differential genes involved in multiple classes based on Gene Ontology (GO) and multiple Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The GO analysis showed that the functions of the differential genes are closely related to the carbohydrate metabolism and other biological processes. KEGG pathway analysis revealed that these genes are mostly enriched in the pathway of antigen processing and presentation, phagosome pathway and type I diabetes pathway and enriched followed by extracellular matrix receptor interaction pathway. Moreover, several other pathways related to amino acid metabolism also showed significant enrichment. Here, the mammary gland transcriptomes of high-yielding yak and low-yielding yaks during lactation have for the first time been compared, and the related differential genes have been screened out and analyzed. Our study paves a way for the further elucidation of the basic molecular mechanism of yak mammary gland tissue, and at the same time provides new ideas for improving the milk production of yaks.
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Affiliation(s)
- Jinbo Wu
- Animal Husbandry Science Institute of ABa Autonomous Prefecture, Hongyuan, P. R. China
| | - Shiming He
- Animal Husbandry Science Institute of ABa Autonomous Prefecture, Hongyuan, P. R. China
| | - Zhonghua Yu
- Animal Husbandry Science Institute of ABa Autonomous Prefecture, Hongyuan, P. R. China
| | - Daoliang Lan
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu, Sichuan, P. R. China
| | - Xianrong Xiong
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu, Sichuan, P. R. China
| | - Zhu Li
- Animal Husbandry Science Institute of ABa Autonomous Prefecture, Hongyuan, P. R. China
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Khalilov RA, Dzhafarova AM, Khizrieva SI, Abdullaev VR. The Effect of Hypothermia on Some Structural and Functional Characteristics of Lactate Dehydrogenase of the Rat Brain. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419030097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Parthasarathy A, Savka MA, Hudson AO. The Synthesis and Role of β-Alanine in Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:921. [PMID: 31379903 PMCID: PMC6657504 DOI: 10.3389/fpls.2019.00921] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 06/28/2019] [Indexed: 05/20/2023]
Abstract
Most studies on amino acids are focused on the proteinogenic amino acids given their essential roles in protein synthesis among other pathways. In addition to 20 ubiquitous amino acids used in protein synthesis, plants synthesize over 250 non-proteinogenic amino acids that are involved in the synthesis of compounds that are anti-herbivory, anti-microbial, response to abiotic stresses, nitrogen storage, toxins against both vertebrates/invertebrates, and plant hormones among others. One such non-proteinogenic acid is β-alanine, which is known mainly for studies on humans. β-Alanine forms a part of pantothenate (vitamin B5), which is incorporated into the universal carbon shuttling compounds Coenzyme A and acyl carrier protein, in all organisms including plants. The focus of this review, however, is on the biosynthesis, metabolism, and the role of β-alanine in plants. There are several functions of β-alanine unique to plants. It is accumulated as a generic stress response molecule involved in protecting plants from temperature extremes, hypoxia, drought, heavy metal shock, and some biotic stresses. There is evidence of its participation in lignin biosynthesis and ethylene production in some species. It is further converted to the osmoprotective compound β-alanine betaine in some species and converted to the antioxidant homoglutathione in others. The polyamines spermine/spermidine, propionate and uracil have been shown to be precursors of β-alanine in plants. However, plants vary in terms of their biosynthetic pathways, and the primary metabolism of β-alanine is far from settled.
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Affiliation(s)
| | | | - André O. Hudson
- The Thomas H. Gosnell School of Life Sciences, College of Science, Rochester Institute of Technology, Rochester, NY, United States
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6
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Javanshad R, Honarvar E, Venter AR. Addition of Serine Enhances Protein Analysis by DESI-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:694-703. [PMID: 30771107 DOI: 10.1007/s13361-018-02129-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/21/2018] [Accepted: 12/27/2018] [Indexed: 05/18/2023]
Abstract
Previous studies have suggested that the loss in sensitivity of DESI-MS for large molecules such as proteins is due to the poor dissolution during the short time scale of desorption and ionization. An investigation into the effect of serine as a solvent additive leads to the interesting observation that there is a concentration-dependent improvement in protein signal intensity when micromolar to low millimolar concentrations of serine is combined with a suitable co-additive in DESI spray. This effect, however, was not observed during similar ESI-MS experiments, where the same solvents and proteins were sprayed directly into the MS inlet. This suggests that the mechanism of signal improvement in DESI is associated with the desorption step of proteins, possibly by facilitating dissolution or improving solubility of proteins on the surface in the solvent micro-layer formed during DESI. Other than poor dissolution, cation adduction such as by sodium ions is also a major contributing factor to the mass-dependent loss in sensitivity in both ESI and DESI, leading to an increase in limits of detection for larger proteins. The adduction becomes a more pressing issue in native-state studies of proteins, as lower charge states are more susceptible to adduction. Previous studies have shown that addition of amino acids to the working spray solution during ESI-MS reduces sodium adduction and can help in stabilization of native-state proteins. Similar to the observed reduction in sodium adducts during native-state ESI-MS, when serine is added to the desorbing spray in DESI-MS, the removal of up to 10 mM NaCl is shown. A selection of proteins with high and low pI and molecular weights was analyzed to investigate the effects of serine on signal intensity by improvements in protein solubility and adduct removal. Graphical Abstract.
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Affiliation(s)
- Roshan Javanshad
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008-5413, USA
| | - Elahe Honarvar
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008-5413, USA
| | - Andre R Venter
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008-5413, USA.
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7
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Affiliation(s)
- I. W. Hamley
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
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8
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Das Mahapatra R, Dey J, Weiss RG. l-Carnosine-Derived Fmoc-Tripeptides Forming pH-Sensitive and Proteolytically Stable Supramolecular Hydrogels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12989-12999. [PMID: 29064707 DOI: 10.1021/acs.langmuir.7b03018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A series of β-amino acid containing tripeptides has been designed and synthesized in order to develop oligopeptide-based, thermoreversible, pH-sensitive, and proteolytically stable hydrogels. The Fmoc [N-(fluorenyl-9-methoxycarbonyl)]-protected tripeptides were found to produce hydrogels in both pH 7 and 2 buffers at a very low concentration (<0.2% w/v). It has been shown that the Fmoc group plays an important role in the gelation process. Also a dependence of gelation ability on hydrophobicity of the side chain of the Fmoc-protected α-amino acid was observed. The effect of the addition of inorganic salts on the gelation process was investigated as well. Spectroscopic studies indicated formation of J-aggregates through π-π stacking interactions between Fmoc groups in solution as well as in the gel state. In the gel phase, these self-assembling tripeptides form long interconnected nanofibrils leading to the formation of 3-dimensional network structure. The hydrogels were characterized by various techniques, including field emission electron microscopy, transmission electron microscopy, atomic force microscopy, rheology, Fourier transform IR, circular dichroism (CD), and wide-angle X-ray diffraction (WAXD) spectroscopy. The CD studies and WAXD analyses show an antiparallel β-sheet structure in the gel state. l-Phenylalanine and l-tyrosine containing tripeptides formed helical aggregates with handedness opposite to those containing l-valine and l-leucine residues. The mechanical stability of the hydrogels was found to depend on the hydrophobicity of the side chain of the tripeptide as well as on the pH of the solution. Also, the tripeptides exhibit in vitro proteolytic stability against proteinase K enzyme.
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Affiliation(s)
- Rita Das Mahapatra
- Department of Chemistry, Indian Institute of Technology Kharagpur , Kharagpur 721 302, India
| | - Joykrishna Dey
- Department of Chemistry, Indian Institute of Technology Kharagpur , Kharagpur 721 302, India
| | - Richard G Weiss
- Department of Chemistry and Institute for Soft Matter Synthesis and Metrology, Georgetown University , Washington, D.C. 20057-1227, United States
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9
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Kar S, Huang BH, Wu KW, Lee CR, Tai Y. A simple N,N'-dicyclohexylurea adduct of β-alanine can self-assemble to generate nano-morphological versatility in response to different environmental conditions. SOFT MATTER 2014; 10:8075-8082. [PMID: 25170841 DOI: 10.1039/c4sm01488j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A single ω-amino acid based molecule "Boc-β-Ala-N,N'-dicyclohexylurea" can form diverse nanostructures such as nano-vesicles, nano-tubes, nano-rods and nano-fibrils by self-assembly, in response to various environmental conditions. Interestingly, the nano-vesicular structures generated from this molecule can encapsulate the highly potent anticancer drug methotrexate, which can be released by salt triggered disruption of these vesicles. This phenomenon indicates the probability of its use in targeted delivery of drugs or any bio-active molecule, utilizing this encapsulation efficiency. Moreover, a surface-induced morphological transformation of these nano-vesicles to nano-fibers can be realized while they interact with hydrocarbon-functionalized surfaces. This phenomenon indicates the probability of their utilization in model study of peptide interaction behavior at liquid-solid interfaces and can be used in advanced study of various biological phenomena and bio-technological applications.
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Affiliation(s)
- Sudeshna Kar
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Taipei-106, Taiwan.
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10
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Levy-Sakin M, Berger O, Feibish N, Sharon N, Schnaider L, Shmul G, Amir Y, Buzhansky L, Gazit E. The influence of chemical chaperones on enzymatic activity under thermal and chemical stresses: common features and variation among diverse chemical families. PLoS One 2014; 9:e88541. [PMID: 24520396 PMCID: PMC3919781 DOI: 10.1371/journal.pone.0088541] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 01/06/2014] [Indexed: 11/18/2022] Open
Abstract
Molecular and chemical chaperones are key components of the two main mechanisms that ensure structural stability and activity under environmental stresses. Yet, chemical chaperones are often regarded only as osmolytes and their role beyond osmotic regulation is not fully understood. Here, we systematically studied a large group of chemical chaperones, representatives of diverse chemical families, for their protective influence under either thermal or chemical stresses. Consistent with previous studies, we observed that in spite of the structural similarity between sugars and sugar alcohols, they have an apparent difference in their protective potential. Our results support the notion that the protective activity is mediated by the solvent and the presence of water is essential. In the current work we revealed that i) polyols and sugars have a completely different profile of protective activity toward trifluoroethanol and thermal stress; ii) minor changes in solvent composition that do not affect enzyme activity, yet have a great effect on the ability of osmolytes to act as protectants and iii) increasing the number of active groups of carbohydrates makes them better protectants while increasing the number of active groups of methylamines does not, as revealed by attempts to synthesize de novo designed methylamines with multiple functional groups.
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Affiliation(s)
- Michal Levy-Sakin
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Or Berger
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Nir Feibish
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Noa Sharon
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Lee Schnaider
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Guy Shmul
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Yaniv Amir
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Ludmila Buzhansky
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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Seidler NW. Dynamic oligomeric properties. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 985:207-47. [PMID: 22851451 DOI: 10.1007/978-94-007-4716-6_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This chapter provides a foundation for further research into the relationship between dynamic oligomeric properties and functional diversity. The structural basis that underlies the conformational sub-states of the GAPDH oligomer is discussed. The issue of protein stability is given a thorough analysis, since it is well-established that the primary strategy for protein oligomerization is to stabilize conformation. Several factors that affect oligomerization are described, including chemical modification by synthetic reagents. The effects of native substrates and coenzymes are also discussed. The curious feature of chloride ions having a de-stabilizing effect on native GAPDH structure is described. Additionally, the role of adenine dinucleotides in tetramer-dimer equilibrium dynamics is suggested to be a major part of the physiological regulation of GAPDH structure and function. This chapter also contends that a vast amount of useful information can come from comparative analyses of diverse species, particularly regarding protein stability and subunit-subunit interaction. Lastly, the concept of domain exchange is introduced as a means of understanding the stabilization of dynamic oligomers, suggesting that inter-subunit contacts may also be a way of masking docking sites to other proteins.
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Affiliation(s)
- Norbert W Seidler
- Department of Biochemistry, Kansas City University of Medicine and Biosciences, Kansas City, MO, USA
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12
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Castelletto V, Cheng G, Stain C, Connon CJ, Hamley IW. Self-assembly of a peptide amphiphile containing L-carnosine and its mixtures with a multilamellar vesicle forming lipid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11599-608. [PMID: 22788380 DOI: 10.1021/la302210b] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The self-assembly of the peptide amphiphile (PA) hexadecyl-(β-alanine-histidine) is examined in aqueous solution, along with its mixtures with multilamellar vesicles formed by DPPC (dipalmitoyl phosphatidylcholine). This PA, denoted C(16)-βAH, contains a dipeptide headgroup corresponding to the bioactive molecule L-carnosine. It is found to self-assemble into nanotapes based on stacked layers of molecules. Bilayers are found to coexist with monolayers in which the PA molecules pack with alternating up-down arrangement so that the headgroups decorate both surfaces. The bilayers become dehydrated as PA concentration increases and the number of layers in the stack decreases to produce ultrathin nanotapes comprised of 2-3 bilayers. Addition of the PA to DPPC multilamellar vesicles leads to a transition to well-defined unilamellar vesicles. The unique ability to modulate the stacking of this PA as a function of concentration, combined with its ability to induce a multilamellar to unilamellar thinning of DPPC vesicles, may be useful in biomaterials applications where the presentation of the peptide function at the surface of self-assembled nanostructures is crucial.
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Affiliation(s)
- V Castelletto
- School of Chemistry, Food Science and Pharmacy, University of Reading, Whiteknights, Reading, United Kingdom.
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Castelletto V, Cheng G, Greenland BW, Hamley IW, Harris PJF. Tuning the self-assembly of the bioactive dipeptide L-carnosine by incorporation of a bulky aromatic substituent. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2980-8. [PMID: 21338121 DOI: 10.1021/la104495g] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The dipeptide L-carnosine has a number of important biological properties. Here, we explore the effect of attachment of a bulky hydrophobic aromatic unit, Fmoc [N-(fluorenyl-9-methoxycarbonyl)] on the self-assembly of Fmoc-L-carnosine, i.e., Fmoc-β-alanine-histidine (Fmoc-βAH). It is shown that Fmoc-βAH forms well-defined amyloid fibrils containing β sheets above a critical aggregation concentration, which is determined from pyrene and ThT fluorescence experiments. Twisted fibrils were imaged by cryogenic transmission electron microscopy. The zinc-binding properties of Fmoc-βAH were investigated by FTIR and Raman spectroscopy since the formation of metal ion complexes with the histidine residue in carnosine is well-known, and important to its biological roles. Observed changes in the spectra may reflect differences in the packing of the Fmoc-dipeptides due to electrostatic interactions. Cryo-TEM shows that this leads to changes in the fibril morphology. Hydrogelation is also induced by addition of an appropriate concentration of zinc ions. Our work shows that the Fmoc motif can be employed to drive the self-assembly of carnosine into amyloid fibrils.
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Affiliation(s)
- V Castelletto
- School of Chemistry, Food Science and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
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14
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New concept in nutrition for the maintenance of the aging eye redox regulation and therapeutic treatment of cataract disease; synergism of natural antioxidant imidazole-containing amino acid-based compounds, chaperone, and glutathione boosting agents: a systemic perspective on aging and longevity emerged from studies in humans. Am J Ther 2010; 17:373-89. [PMID: 20463577 DOI: 10.1097/mjt.0b013e3181d6b6c3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cataract, opacification of the lens, is one of the commonest causes of loss of useful vision during aging, with an estimated 16 million people world-wide affected. The role of nutritional supplementation in prevention of onset or progression of ocular disease is of interest to health care professionals and patients. The aging eye seems to be at considerable risk from oxidative stress. This review outlines the potential role of the new nutritional strategy on redox balance in age-related eye diseases and detail how the synergism and interaction of imidazole-containing amino acid-based compounds (nonhydrolized L-carnosine, histidine), chaperone agents (such as, L-carnosine, D-pantethine), glutathione-boosting agents (N-acetylcysteine, vitamin E, methionine), and N-acetylcarnosine eye drops plays key roles in the function and maintenance of the redox systems in the aging eye and in the treatment of human cataract disease. A novel patented oral health supplement is presented which enhances the anticataract activity of eye drops and activates functional visual acuity. The clinical data demonstrate the effectiveness and safety of a combined oral health care treatment with amino acids possessing chaperone-like activity with N-acetylcarnosine lubricant eye drops. L-carnosine and N-acetylcarnosine protected the chaperone activity of alpha-crystallin and reduced the increased posttranslational modifications of lens proteins. Biological activities of the nonhydrolyzed carnosine in the oral formulation are based on its antioxidant and antiglycating (transglycating) action that, in addition to heavy metal chelation and pH-buffering ability, makes carnosine an essential factor for preventing sight-threatening eye disorders having oxidative stress in their pathogenesis, neurodegeneration, and accumulation of senile features. The findings suggest that synergism is required between carnosine or other imidazole-containing compounds and reduced glutathione in tissues and cells for efficacious protection from protein carbonylation as a biomarker for the ability of the non-toxic compounds to reduce oxidative stress. Potential therapeutic applications of oral forms of nonhydrolized carnosine and their specific mechanisms to manage telomere attrition and vascular aging might help elderly patients to withstand the problems of sight-threatening eye diseases related to oxidative stress and accelerated biological ageing in linked with earlier onset of diseases.
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15
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Babizhayev MA. Designation of imidazole-containing dipeptides as pharmacological chaperones. Hum Exp Toxicol 2010; 30:736-61. [PMID: 20656726 DOI: 10.1177/0960327110377526] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We review the dichotomous regulatory roles of natural imidazole-containing peptidomimetics (N-acetylcarnosine [NAC], carcinine, non-hydrolized carnosine) in maintaining skin homeostasis that determines whether keratinocytes survive or undergo apoptosis in response to various insults and in the development of skin diseases. General strategies addressing common ground techniques to improve absorption of usually active chaperone proteins or their dipeptide inducer (usually poorly absorbed) compounds include encapsulation into hydrophobic carriers, combination with penetration enhancers, active electrical transport or chemical modification to increase hydrophobicity. A growing evidence is presented that demonstrates the ability of NAC (lubricant eye drops) or carcinine to act as pharmacological chaperones, or being synergistically coupled in patented formulations with another imidazole-containing peptidomimetic (such as, Leucyl-histidylhydrazide), to decrease oxidative stress and ameliorate oxidative and excessive glycation stress-related eye disease phenotypes, suggesting that the field of chaperone therapy might hold novel treatments for age-related cataracts, glaucoma, age-related macular degeneration (AMD), and ocular complications of diabetes (OCD). Current efforts are being directed towards exploring therapeutic approaches of pharmacological targeting and human drug delivery for chaperone molecules based on innovative patented strategies.
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Affiliation(s)
- Mark A Babizhayev
- Innovative Vision Products Inc, County of New Castle, Delaware, USA.
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Nowak RJ, Cuny GD, Choi S, Lansbury PT, Ray SS. Improving binding specificity of pharmacological chaperones that target mutant superoxide dismutase-1 linked to familial amyotrophic lateral sclerosis using computational methods. J Med Chem 2010; 53:2709-18. [PMID: 20232802 DOI: 10.1021/jm901062p] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We recently described a set of drug-like molecules obtained from an in silico screen that stabilize mutant superoxide dismutase-1 (SOD-1) linked to familial amyotrophic lateral sclerosis (ALS) against unfolding and aggregation but exhibited poor binding specificity toward SOD-1 in presence of blood plasma. A reasonable but not a conclusive model for the binding of these molecules was proposed on the basis of restricted docking calculations and site-directed mutagenesis of key residues at the dimer interface. A set of hydrogen bonding constraints obtained from these experiments were used to guide docking calculations with compound library around the dimer interface. A series of chemically unrelated hits were predicted, which were experimentally tested for their ability to block aggregation. At least six of the new molecules exhibited high specificity of binding toward SOD-1 in the presence of blood plasma. These molecules represent a new class of molecules for further development into clinical candidates.
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Affiliation(s)
- Richard J Nowak
- Harvard NeuroDiscovery Center, Harvard Medical School, Boston, Massachusetts, USA
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Effects of facultative symbionts and heat stress on the metabolome of pea aphids. ISME JOURNAL 2009; 4:242-52. [PMID: 19907504 DOI: 10.1038/ismej.2009.114] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We examined metabolite pools of pea aphids with different facultative symbiont infections, and characterized their effects on aphid metabolism in baseline and heat stress conditions. The bacterial symbiont Serratia symbiotica protects aphid hosts from the detrimental results of heat stress and shields the obligate symbiont Buchnera from effects of heat. We investigated whether broad effects on metabolism might correlate with this protection. Both facultative symbiont infection and heat treatment had large effects on the aphid metabolome. All three pea aphid facultative symbionts had similar effects on aphid metabolism despite their evolutionary diversity. Paradoxically, heat triggers lysis of many S. symbiotica cells and a correlated rapid reduction in S. symbiotica titres within aphid hosts. We conclude that facultative symbionts can have substantial effects on host metabolic pools, and we hypothesize that the protective effects of S. symbiotica may reflect the delivery of protective metabolites to aphid or Buchnera cells, after heat exposure.
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Fouad WM, Altpeter F. Transplastomic expression of bacterial L-aspartate-alpha-decarboxylase enhances photosynthesis and biomass production in response to high temperature stress. Transgenic Res 2009; 18:707-18. [PMID: 19353301 DOI: 10.1007/s11248-009-9258-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Accepted: 03/20/2009] [Indexed: 10/20/2022]
Abstract
Metabolic engineering for beta-alanine over-production in plants is expected to enhance environmental stress tolerance. The Escherichia coli L-aspartate-alpha-decarboxylase (AspDC) encoded by the panD gene, catalyzes the decarboxylation of L-aspartate to generate beta-alanine and carbon dioxide. The constitutive E. coli panD expression cassette was co-introduced with the constitutive, selectable aadA expression cassette into the chloroplast genome of tobacco via biolistic gene transfer and homologous recombination. Site specific integration of the E. coli panD expression cassette into the chloroplast genome and generation of homotransplastomic plants were confirmed by PCR and Southern blot analysis, respectively, following plant regeneration and germination of seedlings on selective media. PanD expression was verified by assays based on transcript detection and in vitro enzyme activity. The AspDC activities in transplastomic plants expressing panD were drastically increased by high-temperature stress. beta-Alanine accumulated in transplastomic plants at levels four times higher than in wildtype plants. Analysis of chlorophyll fluorescence on plants subjected to severe heat stress at 45 degrees C under light verified that photosystem II (PSII) in transgenic plants had higher thermotolerance than in wildtype plants. The CO(2) assimilation of transplastomic plants expressing panD was more tolerant to high temperature stress than that of wildtype plants, resulting in the production of 30-40% more above ground biomass than wildtype control. The results presented indicate that chloroplast engineering of the beta-alanine pathway by over-expression of the E. coli panD enhances thermotolerance of photosynthesis and biomass production following high temperature stress.
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Affiliation(s)
- W M Fouad
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida-IFAS, Gainesville, FL, USA
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Pei W, Misumi J, Kubota N, Morikawa M, Kimura N. Two new reactive targets of 2,5-hexanedione in vitro – beta-alanine and glycine. Amino Acids 2006; 32:261-4. [PMID: 16733615 DOI: 10.1007/s00726-006-0344-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2005] [Accepted: 02/25/2006] [Indexed: 11/27/2022]
Abstract
In this study, we found that two amino acids reacted with 2,5-hexanedione to form new reaction products in vitro, respectively. In the reaction of beta-alanine and 2,5-hexanedione, a reaction product was obtained and analyses of obtained results showed it was 3-(2,5-dimethyl-1H-pyrrol-1-yl)propanoic acid; in the reaction of glycine and 2,5-hexanedione, a reaction product was also obtained and analyses showed it was (2,5-dimethyl-1H-pyrrol-1-yl)acetic acid. Two reaction products were found to be oxidized easily; in addition, the latter was more easily to be oxidized than the former in the air. Our discoveries demonstrated that reactions between amino acids and 2,5-hexanedione could exist possibly in vitro. At present, it is clear that 2,5-hexanedione causes either axon atrophy or swelling, but the underlying molecular mechanism is still unclear. Since both beta-alanine and glycine are considered as neurotransmitter in the central nervous system, the reaction products remain to be identified in vivo.
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Affiliation(s)
- W Pei
- Department of Public Health and Hygiene, Faculty of Medicine, Oita University, Yufu City, Oita, Japan
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Fouad WM, Rathinasabapathi B. Expression of bacterial L-aspartate-alpha-decarboxylase in tobacco increases beta-alanine and pantothenate levels and improves thermotolerance. PLANT MOLECULAR BIOLOGY 2006; 60:495-505. [PMID: 16525887 DOI: 10.1007/s11103-005-4844-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Accepted: 11/07/2005] [Indexed: 05/07/2023]
Abstract
L- Aspartate-alpha-decarboxylase catalyzes the decarboxylation of L -aspartate to generate Beta-alanine and carbon dioxide. This is an unusual pyruvoyl-dependent enzyme unique to prokaryotes that undergoes limited self-processing. The Escherichia coli pan D gene encoding L- aspartate-alpha-decarboxylase was expressed under a constitutive promoter in transgenic tobacco. Transgene expression was verified by assays based on RNA blots, immunoblots and enzyme activity in vitro. The pan D lines had increased levels of leaf Beta-alanine (1.2- to 4-fold), pantothenate (3.2- to 4.1-fold) and total free amino acids (up to 3.7-fold) compared to wild-type and vector controls. Growth of homozygous lines expressing E. coli L- aspartate-alpha-decarboxylase was less affected than that of the control lines when the plants were stressed for 1 week at 35 degrees C. When transferred from 35 to 30 degrees C for 3 weeks, the Pan D transgenic lines recovered significantly (P
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Affiliation(s)
- Walid M Fouad
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, University of Florida, Gainesville, FL 32611-0690, USA
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