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Roessner R, Michelarakis N, Gräter F, Aponte-Santamaría C. Mechanical forces control the valency of the malaria adhesin VAR2CSA by exposing cryptic glycan binding sites. PLoS Comput Biol 2023; 19:e1011726. [PMID: 38117828 PMCID: PMC10786402 DOI: 10.1371/journal.pcbi.1011726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 01/12/2024] [Accepted: 12/02/2023] [Indexed: 12/22/2023] Open
Abstract
Plasmodium falciparum (Pf) is responsible for the most lethal form of malaria. VAR2CSA is an adhesin protein expressed by this parasite at the membrane of infected erythrocytes for attachment to the placenta, leading to pregnancy-associated malaria. VAR2CSA is a large 355 kDa multidomain protein composed of nine extracellular domains, a transmembrane helix, and an intracellular domain. VAR2CSA binds to Chondroitin Sulphate A (CSA) of the proteoglycan matrix of the placenta. Shear flow, as the one occurring in blood, has been shown to enhance the (VAR2CSA-mediated) adhesion of Pf-infected erythrocytes on the CSA-matrix. However, the underlying molecular mechanism governing this enhancement has remained elusive. Here, we address this question by using equilibrium, force-probe, and docking-based molecular dynamics simulations. We subjected the VAR2CSA protein-CSA sugar complex to a force mimicking the tensile force exerted on this system due to the shear of the flowing blood. We show that upon this force exertion, VAR2CSA undergoes a large opening conformational transition before the CSA sugar chain dissociates from its main binding site. This preferential order of events is caused by the orientation of the molecule during elongation, as well as the strong electrostatic attraction of the sugar to the main protein binding site. Upon opening, two additional cryptic CSA binding sites get exposed and a functional dodecameric CSA molecule can be stably accommodated at these force-exposed positions. Thus, our results suggest that mechanical forces increase the avidity of VAR2CSA by turning it from a monovalent to a multivalent state. We propose this to be the molecular cause of the observed shear-enhanced adherence. Mechanical control of the valency of VAR2CSA is an intriguing hypothesis that can be tested experimentally and which is of relevance for the understanding of the malaria infection and for the development of anti placental-malaria vaccines targeting VAR2CSA.
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Affiliation(s)
- Rita Roessner
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Nicholas Michelarakis
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany
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2
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Mullick D, Rechav K, Leiserowitz L, Regev-Rudzki N, Dzikowski R, Elbaum M. Diffraction contrast in cryo-scanning transmission electron tomography reveals the boundary of hemozoin crystals in situ. Faraday Discuss 2022; 240:127-141. [PMID: 35938388 DOI: 10.1039/d2fd00088a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Malaria is a potentially fatal infectious disease caused by the obligate intracellular parasite Plasmodium falciparum. The parasite infects human red blood cells (RBC) and derives nutrition by catabolism of hemoglobin. As amino acids are assimilated from the protein component, the toxic heme is released. Molecular heme is detoxified by rapid sequestration to physiologically insoluble hemozoin crystals within the parasite's digestive vacuole (DV). Common antimalarial drugs interfere with this crystallization process, leaving the parasites vulnerable to the by-product of their own metabolism. A fundamental debate with important implications on drug mechanism regards the chemical environment of crystallization in situ, whether aqueous or lipid. This issue had been addressed previously by cryogenic soft X-ray tomography. We employ cryo-scanning transmission electron tomography (CSTET) to probe parasite cells throughout the life cycle in a fully hydrated, vitrified state at higher resolution. During the acquisition of CSTET data, Bragg diffraction from the hemozoin provides a uniquely clear view of the crystal boundary at nanometer resolution. No intermediate medium, such as a lipid coating or shroud, could be detected surrounding the crystals. The present study describes a unique application of CSTET in the study of malaria. The findings can be extended to evaluate new drug candidates affecting hemozoin crystal growth.
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Affiliation(s)
- Debakshi Mullick
- Department of Chemical and Biological Physics, Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel.
| | - Katya Rechav
- Electron Microscopy Unit, Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Leslie Leiserowitz
- Department of Molecular Chemistry and Materials Science, Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Neta Regev-Rudzki
- Department of Biomolecular Sciences, Faculty of Biochemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Dzikowski
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, and The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Michael Elbaum
- Department of Chemical and Biological Physics, Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel.
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Wunderlich J. Updated List of Transport Proteins in Plasmodium falciparum. Front Cell Infect Microbiol 2022; 12:926541. [PMID: 35811673 PMCID: PMC9263188 DOI: 10.3389/fcimb.2022.926541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Malaria remains a leading cause of death and disease in many tropical and subtropical regions of the world. Due to the alarming spread of resistance to almost all available antimalarial drugs, novel therapeutic strategies are urgently needed. As the intracellular human malaria parasite Plasmodium falciparum depends entirely on the host to meet its nutrient requirements and the majority of its transmembrane transporters are essential and lack human orthologs, these have often been suggested as potential targets of novel antimalarial drugs. However, membrane proteins are less amenable to proteomic tools compared to soluble parasite proteins, and have thus not been characterised as well. While it had been proposed that P. falciparum had a lower number of transporters (2.5% of its predicted proteome) in comparison to most reference genomes, manual curation of information from various sources led to the identification of 197 known and putative transporter genes, representing almost 4% of all parasite genes, a proportion that is comparable to well-studied metazoan species. This transporter list presented here was compiled by collating data from several databases along with extensive literature searches, and includes parasite-encoded membrane-resident/associated channels, carriers, and pumps that are located within the parasite or exported to the host cell. It provides updated information on the substrates, subcellular localisation, class, predicted essentiality, and the presence or absence of human orthologs of P. falciparum transporters to quickly identify essential proteins without human orthologs for further functional characterisation and potential exploitation as novel drug targets.
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Affiliation(s)
- Juliane Wunderlich
- Max Planck Institute for Infection Biology, Berlin, Germany
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- *Correspondence: Juliane Wunderlich,
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4
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Agnero MA, Konan K, Tokou ZGCS, Kossonou YTA, Dion BS, Kaduki KA, Zoueu JT. Malaria-Infected Red Blood Cell Analysis through Optical and Biochemical Parameters Using the Transport of Intensity Equation and the Microscope's Optical Properties. SENSORS (BASEL, SWITZERLAND) 2019; 19:E3045. [PMID: 31295927 PMCID: PMC6678084 DOI: 10.3390/s19143045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/07/2019] [Accepted: 06/09/2019] [Indexed: 11/16/2022]
Abstract
The accuracy, reliability, speed and cost of the methods used for malaria diagnosis are key to the diseases' treatment and eventual eradication. However, improvement in any one of these requirements can lead to deterioration of the rest due to their interdependence. We propose an optical method that provides fast detection of malaria-infected red blood cells (RBCs) at a lower cost. The method is based on the combination of deconvolution, topography and three-dimensional (3D) refractive index reconstruction of the malaria-infected RBCs by use of the transport of intensity equation. Using our method, healthy RBCs were identified by their biconcave shape, quasi-uniform spatial distribution of their refractive indices and quasi-uniform concentration of hemoglobin. The values of these optical and biochemical parameters were found to be in agreement with the values reported in the literature. Results for the malaria-infected RBCs were significantly different from those of the healthy RBCs. The topography of the cells and their optical and biochemical parameters enabled identification of their stages of infection. This work introduces a significant method of analyzing malaria-infected RBCs at a lower cost and without the use of fluorescent labels for the parasites.
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Affiliation(s)
- Marcel Akpa Agnero
- Laboratoire de Physique de la Matière Condensée et Technologie, UFR SSMT, Université Félix Houphouët-Boigny, 22 BP 582 Abidjan 22, Côte d'Ivoire.
| | - Kouakou Konan
- Laboratoire d'Instrumentation d'Image et Spectroscopie, Institut National Polytechnique Félix Houphouët-Boigny (INPH-B), BP 1093 Yamoussoukro, Côte d'Ivoire
| | | | - Yao Taky Alvarez Kossonou
- Laboratoire d'Instrumentation d'Image et Spectroscopie, Institut National Polytechnique Félix Houphouët-Boigny (INPH-B), BP 1093 Yamoussoukro, Côte d'Ivoire
| | - Bienvenue Sylvère Dion
- Laboratoire d'Instrumentation d'Image et Spectroscopie, Institut National Polytechnique Félix Houphouët-Boigny (INPH-B), BP 1093 Yamoussoukro, Côte d'Ivoire
| | | | - Jérémie Thouakesséh Zoueu
- Laboratoire d'Instrumentation d'Image et Spectroscopie, Institut National Polytechnique Félix Houphouët-Boigny (INPH-B), BP 1093 Yamoussoukro, Côte d'Ivoire
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5
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Weinhardt V, Chen JH, Ekman A, McDermott G, Le Gros MA, Larabell C. Imaging cell morphology and physiology using X-rays. Biochem Soc Trans 2019; 47:489-508. [PMID: 30952801 PMCID: PMC6716605 DOI: 10.1042/bst20180036] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 01/02/2019] [Accepted: 01/09/2019] [Indexed: 02/07/2023]
Abstract
Morphometric measurements, such as quantifying cell shape, characterizing sub-cellular organization, and probing cell-cell interactions, are fundamental in cell biology and clinical medicine. Until quite recently, the main source of morphometric data on cells has been light- and electron-based microscope images. However, many technological advances have propelled X-ray microscopy into becoming another source of high-quality morphometric information. Here, we review the status of X-ray microscopy as a quantitative biological imaging modality. We also describe the combination of X-ray microscopy data with information from other modalities to generate polychromatic views of biological systems. For example, the amalgamation of molecular localization data, from fluorescence microscopy or spectromicroscopy, with structural information from X-ray tomography. This combination of data from the same specimen generates a more complete picture of the system than that can be obtained by a single microscopy method. Such multimodal combinations greatly enhance our understanding of biology by combining physiological and morphological data to create models that more accurately reflect the complexities of life.
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Affiliation(s)
- Venera Weinhardt
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A
- Department of Anatomy, University of California San Francisco, San Francisco, California, U.S.A
| | - Jian-Hua Chen
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A
| | - Axel Ekman
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A
| | - Gerry McDermott
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A
| | - Mark A Le Gros
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A
- Department of Anatomy, University of California San Francisco, San Francisco, California, U.S.A
| | - Carolyn Larabell
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A.
- Department of Anatomy, University of California San Francisco, San Francisco, California, U.S.A
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6
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Wang S, Wang D, Wu Q, Gao K, Wang Z, Wu Z. 3D imaging of a rice pollen grain using transmission X-ray microscopy. JOURNAL OF SYNCHROTRON RADIATION 2015; 22:1091-5. [PMID: 26134816 DOI: 10.1107/s1600577515009716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/20/2015] [Indexed: 05/09/2023]
Abstract
For the first time, the three-dimensional (3D) ultrastructure of an intact rice pollen cell has been obtained using a full-field transmission hard X-ray microscope operated in Zernike phase contrast mode. After reconstruction and segmentation from a series of projection images, complete 3D structural information of a 35 µm rice pollen grain is presented at a resolution of ∼100 nm. The reconstruction allows a clear differentiation of various subcellular structures within the rice pollen grain, including aperture, lipid body, mitochondrion, nucleus and vacuole. Furthermore, quantitative information was obtained about the distribution of cytoplasmic organelles and the volume percentage of each kind of organelle. These results demonstrate that transmission X-ray microscopy can be quite powerful for non-destructive investigation of 3D structures of whole eukaryotic cells.
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Affiliation(s)
- Shengxiang Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 Hezuohua South Road, Hefei, Anhui 230029, People's Republic of China
| | - Dajiang Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 Hezuohua South Road, Hefei, Anhui 230029, People's Republic of China
| | - Qiao Wu
- Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, People's Republic of China
| | - Kun Gao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 Hezuohua South Road, Hefei, Anhui 230029, People's Republic of China
| | - Zhili Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 Hezuohua South Road, Hefei, Anhui 230029, People's Republic of China
| | - Ziyu Wu
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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Yang N, Nho HW, Kalegowda Y, Kim JB, Song J, Shin HJ, Yoon TH. Synchrotron-based Transmission X-ray Microscopy (TXM) Observations of Fully Hydrated Blood Platelets and Their Activation Process. B KOREAN CHEM SOC 2014. [DOI: 10.5012/bkcs.2014.35.9.2625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Kim K, Yoon H, Diez-Silva M, Dao M, Dasari RR, Park Y. High-resolution three-dimensional imaging of red blood cells parasitized by Plasmodium falciparum and in situ hemozoin crystals using optical diffraction tomography. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:011005. [PMID: 23797986 PMCID: PMC4019420 DOI: 10.1117/1.jbo.19.1.011005] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 05/06/2013] [Accepted: 05/29/2013] [Indexed: 05/18/2023]
Abstract
We present high-resolution optical tomographic images of human red blood cells (RBC) parasitized by malaria-inducing Plasmodium falciparum (Pf)-RBCs. Three-dimensional (3-D) refractive index (RI) tomograms are reconstructed by recourse to a diffraction algorithm from multiple two-dimensional holograms with various angles of illumination. These 3-D RI tomograms of Pf-RBCs show cellular and subcellular structures of host RBCs and invaded parasites in fine detail. Full asexual intraerythrocytic stages of parasite maturation (ring to trophozoite to schizont stages) are then systematically investigated using optical diffraction tomography algorithms. These analyses provide quantitative information on the structural and chemical characteristics of individual host Pf-RBCs, parasitophorous vacuole, and cytoplasm. The in situ structural evolution and chemical characteristics of subcellular hemozoin crystals are also elucidated.
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Affiliation(s)
- Kyoohyun Kim
- Korea Advanced Institute of Science and Technology, Department of Physics, Daejeon 305-701, Republic of Korea
| | - HyeOk Yoon
- Korea Advanced Institute of Science and Technology, Department of Physics, Daejeon 305-701, Republic of Korea
| | - Monica Diez-Silva
- Massachusetts Institute of Technology, Department of Material Science and Engineering, Cambridge, Massachusetts 02142
| | - Ming Dao
- Massachusetts Institute of Technology, Department of Material Science and Engineering, Cambridge, Massachusetts 02142
| | - Ramachandra R. Dasari
- Massachusetts Institute of Technology, George R. Harrison Spectroscopy Laboratory, Cambridge, Massachusetts 02194
| | - YongKeun Park
- Korea Advanced Institute of Science and Technology, Department of Physics, Daejeon 305-701, Republic of Korea
- Address all correspondence to: YongKeun Park, Korea Advanced Institute of Science and Technology, Department of Physics, 291 Daehak-Ro Yusung-Gu, Daejeon 305-701, Republic of Korea. Tel: (82) 42-350-2514; Fax: (82) 42-350-7160; E-mail:
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9
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Serebrennikova YM, Patel J, Milhous WK, Garcia-Rubio LH, Huffman DE, Smith JM. Spectrophotometric detection of susceptibility to anti-malarial drugs. Malar J 2013; 12:305. [PMID: 23992478 PMCID: PMC3849014 DOI: 10.1186/1475-2875-12-305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 08/02/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With malaria drug resistance increasing in prevalence and severity, new technologies are needed to aid and improve the accuracy and clinical relevance of laboratory or field testing for malaria drug resistance. This study presents a method based on simple and reagentless spectroscopic measurements coupled with comprehensive spectral interpretation analysis that provides valuable quantitative information on the morphological and compositional responses of Plasmodium falciparum and infected red blood cells (IRBCs) to anti-malarial treatment. METHODS The changes in the size, internal structure, nucleotide and haemozoin composition of the parasites as well as the morphology (size and shape) and haemoglobin composition of the IRBCs treated with dihydroartemisinin (DHA) and mefloquine (MFQ) were investigated using a spectral interpretation analysis. RESULTS DHA treatment reduced the sizes of the parasites and their structural organelles. The haemoglobin composition of the host IRBCs determined from spectroscopic analysis changed negligibly following DHA treatment. MFQ treated parasites grew to the same size as those from parallel non-treated cultures but lacked haemozoin. Lesser deformation of the cell shape and no haemoglobin depletion were detected for the IRBCs of MFQ treated cultures. CONCLUSIONS The spectroscopic analysis method proved to be sensitive for recognition of the effects of anti-malarial treatment on the structure and composition of the parasites and IRBCs. The method can have significant potential for research and clinical applications such as evaluating patient specimens for drug action, drug effects or for therapeutic monitoring.
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Affiliation(s)
- Yulia M Serebrennikova
- College of Public Health, University of South Florida, 13201 Bruce B, Downs Blvd,, Tampa, FL 33612, USA.
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10
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Vitrification of thick samples for soft X-ray cryo-tomography by high pressure freezing. J Struct Biol 2012; 181:77-81. [PMID: 23079478 DOI: 10.1016/j.jsb.2012.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/03/2012] [Accepted: 10/08/2012] [Indexed: 11/22/2022]
Abstract
Soft X-ray cryo-microscopy (cryo-XT) offers an ideal complement to electron cryo-microscopy (cryo-EM). Cryo-XT is applicable to samples more than an order of magnitude thicker than cryo-EM, albeit at a more modest resolution of tens of nanometers. Furthermore, the natural contrast obtained in the "water-window" by differential absorption by organic matter vs water yields detailed images of organelles, membranes, protein complexes, and other cellular components. Cryo-XT is thus ideally suited for tomography of eukaryotic cells. The increase in sample thickness places more stringent demands on sample preparation, however. The standard method for cryo-EM, i.e., plunging to a cryogenic fluid such as liquid ethane, is no longer ideally suited to obtain vitrification of thick samples for cryo-XT. High pressure freezing is an alternative approach, most closely associated with freeze-substitution and embedding, or with electron cryo-microscopy of vitreous sections (CEMOVIS). We show here that high pressure freezing can be adapted to soft X-ray tomography of whole vitrified samples, yielding a highly reliable method that avoids crystallization artifacts and potentially offers improved imaging conditions in samples not amenable to plunge-freezing.
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11
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Zheng T, Li W, Guan Y, Song X, Xiong Y, Liu G, Tian Y. Quantitative 3D imaging of yeast by hard X-ray tomography. Microsc Res Tech 2011; 75:662-6. [PMID: 22505187 DOI: 10.1002/jemt.21108] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/16/2011] [Indexed: 11/07/2022]
Abstract
Full-field hard X-ray tomography could be used to obtain three-dimensional (3D) nanoscale structures of biological samples. The image of the fission yeast, Schizosaccharomyces pombe, was clearly visualized based on Zernike phase contrast imaging technique and heavy metal staining method at a spatial resolution better than 50 nm at the energy of 8 keV. The distributions and shapes of the organelles during the cell cycle were clearly visualized and two types of organelle were distinguished. The results for cells during various phases were compared and the ratios of organelle volume to cell volume can be analyzed quantitatively. It showed that the ratios remained constant between growth and division phase and increased strongly in stationary phase, following the shape and size of two types of organelles changes. Our results demonstrated that hard X-ray microscopy was a complementary method for imaging and revealing structural information for biological samples.
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Affiliation(s)
- Ting Zheng
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
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12
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Cho S, Kim S, Kim Y, Park Y. Optical imaging techniques for the study of malaria. Trends Biotechnol 2011; 30:71-9. [PMID: 21930322 DOI: 10.1016/j.tibtech.2011.08.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 02/07/2023]
Abstract
Malarial infection needs to be imaged to reveal the mechanisms behind malaria pathophysiology and to provide insights to aid in the diagnosis of the disease. Recent advances in optical imaging methods are now being transferred from physics laboratories to the biological field, revolutionizing how we study malaria. To provide insight into how these imaging techniques can improve the study and treatment of malaria, we summarize recent progress on optical imaging techniques, ranging from in vitro visualization of the disease progression of malaria infected red blood cells (iRBCs) to in vivo imaging of malaria parasites in the liver.
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Affiliation(s)
- Sangyeon Cho
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea
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13
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Yang Y, Li W, Liu G, Zhang X, Chen J, Wu W, Guan Y, Xiong Y, Tian Y, Wu Z. 3D visualization of subcellular structures of Schizosaccharomyces pombe by hard X-ray tomography. J Microsc 2011; 240:14-20. [PMID: 21050209 DOI: 10.1111/j.1365-2818.2010.03379.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cellular structures of the fission yeast, Schizosaccharomyces pombe, were examined by using hard X-ray tomography. Since cells are nearly transparent to hard X-rays, Zernike phase contrast and heavy metal staining were introduced to improve image contrast. Through using such methods, images taken at 8 keV displayed sufficient contrast for observing cellular structures. The cell wall, the intracellular organelles and the entire structural organization of the whole cells were visualized in three-dimensional at a resolution better than 100 nm. Comparison between phase contrast and absorption contrast was also made, indicating the obvious advantage of phase contrast for cellular imaging at this energy. Our results demonstrate that hard X-ray tomography with Zernike phase contrast is suitable for cellular imaging. Its unique abilities make it have potential to become a useful tool for revealing structural information from cells, especially thick eukaryotic cells.
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Affiliation(s)
- Y Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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14
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Serebrennikova YM, Patel J, Milhous WK, García-Rubio LH. Quantitative analysis of morphological alterations in Plasmodium falciparum infected red blood cells through theoretical interpretation of spectral measurements. J Theor Biol 2010; 265:493-500. [PMID: 20665965 DOI: 10.1016/j.jtbi.2010.05.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Spectroscopic analysis can provide valuable insights into morphological and biochemical cellular transformations caused by diseases. However, traditional spectroscopic methods and the corresponding spectral interpretation approaches have been challenged by the complexities of the cell shape, orientation, and internal structure. Here we present an elegant spectral interpretation model that enables accurate quantitative analysis of the UV-visible spectra of red blood cells (RBCs) parasitized by the lethal human malaria parasite, Plasmodium falciparum. The model is based on the modified Mie theory (MMT) approach that incorporates the effects of the nonsphericity and orientation and multilayered cell structure to account for complex composition of the infected RBCs (IRBCs). We determine the structure and composition of the IRBCs and address unresolved matters over the alterations induced by the intraerythrocytic development of P. falciparum. The results indicate deformation and swelling of the IRBCs during the trophozoite stage of P. falciparum that is followed by substantial shrinkage during the schizont stages. We determine that up to 90% depletion of hemoglobin from the RBC cytosol does not lead to a net loss of iron from the infected cells. We quantitatively follow the morphological changes in the parasites during the intraerythrocytic development by applying the interpretation model to the UV-visible spectroscopic measurements of the IRBCs. We expect this method of quantitative spectroscopic characterization of the diseased cells to have practical clinical utility for rapid diagnosis, therapeutic monitoring, and drug susceptibility testing.
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Affiliation(s)
- Yulia M Serebrennikova
- College of Public Health, University of South Florida, 13201 Bruce B. Downs Boulevard, Tampa, FL 33830, USA.
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15
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Hanssen E, Knoechel C, Klonis N, Abu-Bakar N, Deed S, LeGros M, Larabell C, Tilley L. Cryo transmission X-ray imaging of the malaria parasite, P. falciparum. J Struct Biol 2010; 173:161-8. [PMID: 20826218 DOI: 10.1016/j.jsb.2010.08.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/13/2010] [Accepted: 08/25/2010] [Indexed: 11/19/2022]
Abstract
Cryo transmission X-ray microscopy in the "water window" of photon energies has recently been introduced as a method that exploits the natural contrast of biological samples. We have used cryo tomographic X-ray imaging of the intra-erythrocytic malaria parasite, Plasmodium falciparum, to undertake a survey of the cellular features of this important human pathogen. We examined whole hydrated cells at different stages of growth and defined some of the structures with different X-ray density, including the parasite nucleus, cytoplasm, digestive vacuole and the hemoglobin degradation product, hemozoin. As the parasite develops from an early cup-shaped morphology to a more rounded shape, puncta of hemozoin are formed; these coalesce in the mature trophozoite into a central compartment. In some trophozoite stage parasites we observed invaginations of the parasite surface and, using a selective permeabilization process, showed that these remain connected to the RBC cytoplasm. Some of these invaginations have large openings consistent with phagocytic structures and we observed independent endocytic vesicles in the parasite cytoplasm which appear to play a role in hemoglobin uptake. In schizont stage parasites staggered mitosis was observed and X-ray-dense lipid-rich structures were evident at their apical ends of the developing daughter cells. Treatment of parasites with the antimalarial drug artemisinin appears to affect parasite development and their ability to produce the hemoglobin breakdown product, hemozoin.
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Affiliation(s)
- Eric Hanssen
- Electron Microscopy Unit Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia.
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16
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Lim J, Shin HJ, Chae KH, Hwang CC, Hwang HN, Hong CK. A compact, sample-in-atmospheric-pressure soft x-ray microscope developed at Pohang Light Source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:063702. [PMID: 20590241 DOI: 10.1063/1.3432000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A full-field transmission soft x-ray microscope (TXM) was developed at the Pohang Light Source. With a 2 mm diameter condenser zone plate and a 40 nm outermost-zone-width objective zone plate, the TXM's achieved spatial resolution is better than 50 nm at the photon energy of 500 eV (wavelength: 2.49 nm). The TXM is portable and mounted in tandem with a 7B1 spectroscopy end station. The sample position is outside the vacuum, allowing for quick sample changes and enhanced in situ experimental capability. In addition, the TXM is pinhole-free and easy to align, having commercial mounts located outside the vacuum components.
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Affiliation(s)
- Jun Lim
- Pohang Accelerator Laboratory, POSTECH, San31, Pohang 790-784, Republic of Korea
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17
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Modeling of hemodynamics arising from malaria infection. J Biomech 2010; 43:1386-93. [DOI: 10.1016/j.jbiomech.2010.01.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 12/11/2009] [Accepted: 01/05/2010] [Indexed: 11/20/2022]
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18
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Williams GJ, Hanssen E, Peele AG, Pfeifer MA, Clark J, Abbey B, Cadenazzi G, de Jonge MD, Vogt S, Tilley L, Nugent KA. High-resolution X-ray imaging of Plasmodium falciparum-infected red blood cells. Cytometry A 2008; 73:949-57. [PMID: 18671251 DOI: 10.1002/cyto.a.20616] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Methods for imaging cellular architecture and ultimately macromolecular complexes and individual proteins, within a cellular environment, are an important goal for cell and molecular biology. Coherent diffractive imaging (CDI) is a method of lensless imaging that can be applied to any individual finite object. A diffraction pattern from a single biological structure is recorded and an iterative Fourier transform between real space and reciprocal space is used to reconstruct information about the architecture of the sample to high resolution. As a test system for cellular imaging, we have applied CDI to an important human pathogen, the malaria parasite, Plasmodium falciparum. We have employed a novel CDI approach, known as Fresnel CDI, which uses illumination with a curved incident wavefront, to image red blood cells infected with malaria parasites. We have examined the intrinsic X-ray absorption contrast of these cells and compared them with cells contrasted with heavy metal stains or immunogold labeling. We compare CDI images with data obtained from the same cells using scanning electron microscopy, light microscopy, and scanning X-ray fluorescence microscopy. We show that CDI can offer new information both within and at the surface of complex biological specimens at a spatial resolution of better than 40 nm. and we demonstrate an imaging modality that conveniently combines scanning X-ray fluorescence microscopy with CDI. The data provide independent confirmation of the validity of the coherent diffractive image and demonstrate that CDI offers the potential to become an important and reliable new high-resolution imaging modality for cell biology. CDI can detect features at high resolution within unsectioned cells.
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Affiliation(s)
- Garth J Williams
- ARC Centre of Excellence for Coherent X-Ray Science & School of Physics, The University of Melbourne, Vic., 3010 Australia
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19
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Miranda K, de Souza W, Plattner H, Hentschel J, Kawazoe U, Fang J, Moreno SNJ. Acidocalcisomes in Apicomplexan parasites. Exp Parasitol 2008; 118:2-9. [PMID: 17761167 DOI: 10.1016/j.exppara.2007.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 07/19/2007] [Accepted: 07/21/2007] [Indexed: 10/23/2022]
Abstract
Acidocalcisomes are acidic calcium stores found in diverse organisms, being conserved from bacteria to man. They posses an acidic matrix that contains several cations bound to phosphates, mainly present in the form of short and long polyphosphate chains. Their matrix is acidified through the action of proton pumps such as a vacuolar proton ATPase and a vacuolar proton pyrophosphatase. The calcium uptake occurs through a Ca2+/H+ counter transporting ATPase located in the membrane of the organelle. Acidocalcisomes have been identified in a variety of microorganisms, including Apicomplexan parasites such as Plasmodium and Eimeria species, and in Toxoplasma gondii. In this paper, we review the structural, biochemical and physiological aspects of acidocalcisomes in Apicomplexan parasites and discuss their functional roles in the maintenance of intracellular ion homeostasis.
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Affiliation(s)
- Kildare Miranda
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, 350 Paul D. Coverdell Center, University of Georgia, Athens, GA 30602, USA
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20
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Anderson MG, Haraszti T, Petersen GE, Wirick S, Jacobsen C, John SWM, Grunze M. Scanning transmission X-ray microscopic analysis of purified melanosomes of the mouse iris. Micron 2006; 37:689-98. [PMID: 16723235 DOI: 10.1016/j.micron.2006.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 03/14/2006] [Accepted: 03/15/2006] [Indexed: 11/17/2022]
Abstract
Melanosomes are specialized intracellular membrane bound organelles that produce and store melanin pigment. The composition of melanin and distribution of melanosomes determine the color of many mammalian tissues, including the hair, skin, and iris. However, the presence of melanosomes within a tissue carries potentially detrimental risks related to the cytotoxic indole-quinone intermediates produced during melanin synthesis. In order to study melanosomal molecules, including melanin and melanin-related intermediates, we have refined methods allowing spectromicroscopic analysis of purified melanosomes using scanning transmission X-ray microscopy. Here, we present for the first time absorption data for melanosomes at the carbon absorption edge ranging from 284 to 290 eV. High-resolution images of melanosomes at discrete energies demonstrate that fully melanized mature melanosomes are internally non-homogeneous, suggesting the presence of an organized internal sub-structure. Spectra of purified melanosomes are complex, partially described by a predominating absorption band at 288.4 eV with additional contributions from several minor bands. Differences in these spectra were detectable between samples from two strains of inbred mice known to harbor genetically determined melanosomal differences, DBA/2J and C57BL/6J, and are likely to represent signatures arising from biologically relevant and tractable phenomena.
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Affiliation(s)
- Michael G Anderson
- Department of Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, United States.
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21
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Kim KW, Kwon Y, Nam KY, Lim JH, Kim KG, Chon KS, Kim BH, Kim DE, Kim J, Ahn BN, Shin HJ, Rah S, Kim KH, Chae JS, Gweon DG, Kang DW, Kang SH, Min JY, Choi KS, Yoon SE, Kim EA, Namba Y, Yoon KH. Compact soft x-ray transmission microscopy with sub-50 nm spatial resolution. Phys Med Biol 2006; 51:N99-107. [PMID: 16510949 DOI: 10.1088/0031-9155/51/6/n01] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this paper, the development of compact transmission soft x-ray microscopy (XM) with sub-50 nm spatial resolution for biomedical applications is described. The compact transmission soft x-ray microscope operates at lambda = 2.88 nm (430 eV) and is based on a tabletop regenerative x-ray source in combination with a tandem ellipsoidal condenser mirror for sample illumination, an objective micro zone plate and a thinned back-illuminated charge coupled device to record an x-ray image. The new, compact x-ray microscope system requires the fabrication of proper x-ray optical devices in order to obtain high-quality images. For an application-oriented microscope, the alignment procedure is fully automated via computer control through a graphic user interface. In imaging studies using our compact XM system, a gold mesh image was obtained with 45 nm resolution at x580 magnification and 1 min exposure. Images of a biological sample (Coscinodiscus oculoides) were recorded.
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Affiliation(s)
- Kyong Woo Kim
- Department of Radiology and Institute for Radiological Imaging Science, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749, Korea
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22
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Jearanaikoon S, Abraham-Peskir JV. An X-ray microscopy perspective on the effect of glutaraldehyde fixation on cells. J Microsc 2005; 218:185-92. [PMID: 15857380 DOI: 10.1111/j.1365-2818.2005.01472.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
X-ray microscopy (XRM) is the only microscopy technique that can provide high-resolution (30 nm) imaging of biological specimens without the need to fix, stain or section them. We aim to determine the effect, if any, of glutaraldehyde fixation on algae cells from the XRM perspective and thus provide beneficial information for both X-ray and electron microscopists on artefacts induced by glutaraldehyde fixation. Three species of microalgae, Microcystis aeruginosa, Anabaena spiroides and Chlorella vulgaris, were used in this study. XRM images were obtained from unfixed and glutaraldehyde-fixed cells and cell diameter and percentage X-ray absorbency were measured. The mean diameter of cells from fixed preparations was smaller than from unfixed preparations; the mean diameter of M. aeruginosa cells was significantly reduced from 3.92 microm in unfixed cells to 3.43 microm in fixed cells (P < 0.05); in C. vulgaris the diameter of cells was also significantly reduced from 3.50 microm in unfixed to 2.98 microm in fixed samples (P < 0.05); whereas there was no significant reduction in the diameter of A. spiroides cells (4.04-3.90 microm). The protein crosslinking mechanism of glutaraldehyde probably generated free water molecules, which play an important role in radiation damage induced by X-rays. This was seen as mass loss and cell shrinkage, which in the present study occurred more frequently in fixed cells than in unfixed cells. In addition, we demonstrated that the uptake of glutaraldehyde by cells makes all protein constituents in the cell organize into a closely packed configuration, thus causing a rise in the percentage of X-ray absorbency. In fixed cells, this rise was approximately by a factor of two compared with unfixed samples in which protein constituents inside the cell are arranged in their native form.
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Affiliation(s)
- S Jearanaikoon
- Institute for Storage Ring Facilities (ISA), Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark.
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23
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Ruiz FA, Luo S, Moreno SNJ, Docampo R. Polyphosphate content and fine structure of acidocalcisomes of Plasmodium falciparum. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2004; 10:563-567. [PMID: 15525430 DOI: 10.1017/s1431927604040875] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2003] [Indexed: 05/24/2023]
Abstract
Although acidocalcisomes have been well characterized morphologically in other apicomplexan parasites, no such characterization has been done in Plasmodium spp. Here, we report that Plasmodium falciparum merozoites possess electron-dense organelles rich in phosphorus and calcium, as detected by X-ray microanalysis of intact cells, which are similar to the acidocalcisomes of other apicomplexans, but of more irregular form. In agreement with these results malaria parasites possess large amounts of short- and long-chain polyphosphate (polyP), which are associated with acidocalcisomes in other organisms. PolyP levels were highest in the trophozoite stage of the parasite. Treatment of isolated trophozoites with chloroquine resulted in a significant hydrolysis of polyP. Taken together, these results provide evidence that acidocalcisomes from Plasmodium falciparum do not differ significantly from acidocalcisomes of other apicomplexan parasites.
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Affiliation(s)
- Felix A Ruiz
- Laboratory of Molecular Parasitology, Department of Pathobiology and Center for Zoonoses Research, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
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24
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Mayo SC, Miller PR, Wilkins SW, Davis TJ, Gao D, Gureyev TE, Paganin D, Parry DJ, Pogany A, Stevenson AW. Quantitative X-ray projection microscopy: phase-contrast and multi-spectral imaging. J Microsc 2002; 207:79-96. [PMID: 12180954 DOI: 10.1046/j.1365-2818.2002.01046.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We outline a new approach to X-ray projection microscopy in a scanning electron microscope (SEM), which exploits phase contrast to boost the quality and information content of images. These developments have been made possible by the combination of a high-brightness field-emission gun (FEG)-based SEM, direct detection CCD technology and new phase retrieval algorithms. Using this approach we have been able to obtain spatial resolution of < 0.2 micro m and have demonstrated novel features such as: (i) phase-contrast enhanced visibility of high spatial frequency image features (e.g. edges and boundaries) over a wide energy range; (ii) energy-resolved imaging to simultaneously produce multiple quasi-monochromatic images using broad-band polychromatic illumination; (iii) easy implementation of microtomography; (iv) rapid and robust phase/amplitude-retrieval algorithms to enable new real-time and quantitative modes of microscopic imaging. These algorithms can also be applied successfully to recover object-plane information from intermediate-field images, unlocking the potentially greater contrast and resolution of the intermediate-field regime. Widespread applications are envisaged for fields such as materials science, biological and biomedical research and microelectronics device inspection. Some illustrative examples are presented. The quantitative methods described here are also very relevant to projection microscopy using other sources of radiation, such as visible light and electrons.
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Affiliation(s)
- S C Mayo
- CSIRO, Manufacturing Science & Technology, PB33 Clayton Sth MDC, Vic 3169, Australia
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25
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Bannister LH, Hopkins JM, Fowler RE, Krishna S, Mitchell GH. A brief illustrated guide to the ultrastructure of Plasmodium falciparum asexual blood stages. PARASITOLOGY TODAY (PERSONAL ED.) 2000; 16:427-33. [PMID: 11006474 DOI: 10.1016/s0169-4758(00)01755-5] [Citation(s) in RCA: 219] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Interpretation of the new information arising from the Plasmodium falciparum Genome Project requires a good working knowledge of the ultrastructure of the parasite; however many aspects of the morphology of this species remain obscure. Lawrence Bannister, John Hopkins and colleagues here give an illustrated overview of the three-dimensional (3-D) organization of the merozoite, ring, trophozoite and schizont stages of the parasite, based on available data that include 3-D reconstruc-tion from serial electron microscope sections. The review describes the chief organelles present in these stages, emphasizing the continuity of structure in addition to specialized, stage-specific features developed during the asexual erythrocytic cycle.
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Affiliation(s)
- L H Bannister
- Centre for Neuroscience, Hodgkin Building, Guy's, King's and St Thomas' Hospitals School of Basic Medical Science, KCL, Guy's Campus, SE1 1UL, London, UK.
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26
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Abstract
The malaria parasite invades the human erythrocyte and converts this simple "sack of haemoglobin" back into a functional eukaryotic cell. Parasite-encoded proteins are trafficked to the red blood cell membrane where they modify its properties to meet the needs of the intracellular parasite. Trafficking of proteins within the parasite probably occurs via a "classical" vesicle-mediated secretory pathway; however, the transit of proteins from the parasite plasma membrane to the erythrocyte membrane appears to involve both a novel vesicle-mediated pathway and a direct protein-translocation system. The polypeptide signals that direct parasite proteins into these novel export pathways may include an unusual "internal" hydrophobic sequence, as well as a series of basic motifs.
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Affiliation(s)
- M Foley
- Department of Biochemistry, La Trobe University, Bundoora, Victoria, Australia
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27
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Jacobsen C, Kirz J. X-ray microscopy with synchrotron radiation. NATURE STRUCTURAL BIOLOGY 1998; 5 Suppl:650-3. [PMID: 9699617 DOI: 10.1038/1341] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- C Jacobsen
- Department of Physics and Astronomy, State University of New York at Stony Brook 11794-3800, USA.
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