1
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Nonappa. Precision nanoengineering for functional self-assemblies across length scales. Chem Commun (Camb) 2023; 59:13800-13819. [PMID: 37902292 DOI: 10.1039/d3cc02205f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
As nanotechnology continues to push the boundaries across disciplines, there is an increasing need for engineering nanomaterials with atomic-level precision for self-assembly across length scales, i.e., from the nanoscale to the macroscale. Although molecular self-assembly allows atomic precision, extending it beyond certain length scales presents a challenge. Therefore, the attention has turned to size and shape-controlled metal nanoparticles as building blocks for multifunctional colloidal self-assemblies. However, traditionally, metal nanoparticles suffer from polydispersity, uncontrolled aggregation, and inhomogeneous ligand distribution, resulting in heterogeneous end products. In this feature article, I will discuss how virus capsids provide clues for designing subunit-based, precise, efficient, and error-free self-assembly of colloidal molecules. The atomically precise nanoscale proteinic subunits of capsids display rigidity (conformational and structural) and patchy distribution of interacting sites. Recent experimental evidence suggests that atomically precise noble metal nanoclusters display an anisotropic distribution of ligands and patchy ligand bundles. This enables symmetry breaking, consequently offering a facile route for two-dimensional colloidal crystals, bilayers, and elastic monolayer membranes. Furthermore, inter-nanocluster interactions mediated via the ligand functional groups are versatile, offering routes for discrete supracolloidal capsids, composite cages, toroids, and macroscopic hierarchically porous frameworks. Therefore, engineered nanoparticles with atomically precise structures have the potential to overcome the limitations of molecular self-assembly and large colloidal particles. Self-assembly allows the emergence of new optical properties, mechanical strength, photothermal stability, catalytic efficiency, quantum yield, and biological properties. The self-assembled structures allow reproducible optoelectronic properties, mechanical performance, and accurate sensing. More importantly, the intrinsic properties of individual nanoclusters are retained across length scales. The atomically precise nanoparticles offer enormous potential for next-generation functional materials, optoelectronics, precision sensors, and photonic devices.
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Affiliation(s)
- Nonappa
- Facutly of Engineering and Natural Sciences, Tampere University, FI-33720, Tampere, Finland.
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2
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The Au 25(pMBA) 17Diglyme Cluster. Molecules 2021; 26:molecules26092562. [PMID: 33924805 PMCID: PMC8124888 DOI: 10.3390/molecules26092562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/24/2021] [Accepted: 04/26/2021] [Indexed: 11/25/2022] Open
Abstract
A modification of Au25(pMBA)18 that incorporates one diglyme ligand as a direct synthetic product is reported. Notably the expected statistical production of clusters containing other ligand stoichiometries is not observed. This Au25(pMBA)17diglyme product is characterized by electrospray ionization mass spectrometry (ESI-MS) and optical spectroscopy. Thiolate for thiolate ligand exchange proceeds on this cluster, whereas thiolate for diglyme ligand exchange does not.
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3
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Wu H, Fang YG, Anumula R, Andrew GN, Cui G, Fang W, Luo Z, Yao J. A mono-copper doped undeca-gold cluster with up-converted and anti-stokes emissions of fluorescence and phosphorescence. NANOSCALE 2021; 13:5300-5306. [PMID: 33660721 DOI: 10.1039/d0nr07624d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We have synthesized single crystals of a highly stable Cu-doped undeca-gold cluster protected by both triphenylphosphine (PPh3) and 2-pyridinethiol (-SPy) ligands, formulated as [Au11Cu1(PPh3)7(SPy)3]+. This cluster (Au11Cu1 NCs for short) has a metallic core of C3v Au@Au10 with the Cu atom capped on one of the nine triangular facets and it is triply-coordinated to three N atoms of the SPy ligands of which the sulfur atom simultaneously binds to three adjacent Au atoms via singly-coordinated S-Au bonds, respectively. The other seven gold atoms form a crown structure by a link of three orthogons with common sides and are protected by seven PPh3 ligands. Besides the well-organized coordination, this Au11Cu1 nanocluster is demonstrated to exhibit superatom stability of the metallic core within 8 valence electrons (assuming that the 3 electrophilic-SPy ligands capture 3 electrons from the metal center). More interestingly, this Au11Cu1 nanocluster shows interesting emissions in both ultraviolet visible (UV-Vis) and near infrared (NIR) regions, and the emissions display novel anti-Stokes up-conversion lasing characteristics. TD-DFT calculated UV-vis and emission spectra well reproduce the experimental results, shedding light on the nature of excitation states and underlying mechanism of electronic transitions between diverse energy levels of such a monolayer-protected bimetallic cluster.
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Affiliation(s)
- Haiming Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS) and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100090, China.
| | - Ye-Guang Fang
- Key Laboratory of Theoretical and Computational Photochemistry, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Rajini Anumula
- Beijing National Laboratory for Molecular Sciences (BNLMS) and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100090, China.
| | - Gaya N Andrew
- Beijing National Laboratory for Molecular Sciences (BNLMS) and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100090, China.
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Zhixun Luo
- Beijing National Laboratory for Molecular Sciences (BNLMS) and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100090, China.
| | - Jiannian Yao
- Beijing National Laboratory for Molecular Sciences (BNLMS) and State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100090, China.
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4
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Abstract
An important milestone in electron microscopy was the first visualization of single atoms in 1970 with the STEM designed by Albert Crewe. This achievement inspired thoughts that single heavy atoms could be used as super high resolution labels of biological structures by, for example, covalently reacting a heavy atom reagent at the active site of an enzyme. Further investigation of heavy atoms on thin carbon films revealed that they hopped about and that this was not solely thermal motion, but beam induced, since cooling the specimen had little effect. Attempts were made to try various heavy atom compounds but alas, these all behaved similarly, with about 10% of the atoms moving 3-10 Å on successive scans. A gallant effort by M. Beer to sequence DNA using heavy atom base specific labels befell similar problems where the motion of the label prevented high resolution coordinates from being measured.
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5
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Lara HH, Black DM, Moon C, Orr E, Lopez P, Alvarez MM, Baghdasarian G, Lopez-Ribot J, Whetten RL. Activating a Silver Lipoate Nanocluster with a Penicillin Backbone Induces a Synergistic Effect against S. aureus Biofilm. ACS OMEGA 2019; 4:21914-21920. [PMID: 31891070 PMCID: PMC6933807 DOI: 10.1021/acsomega.9b02908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/27/2019] [Indexed: 05/21/2023]
Abstract
Many antibiotic resistances to penicillin have been reported, making them obsolete against multiresistant bacteria. Because penicillins act by inhibiting cell wall production while silver particles disrupt the cell wall directly, a synergetic effect is anticipated when both modes of action are incorporated into a chimera cluster. To test this hypothesis, the lipoate ligands (LA) of a silver cluster (Ag29) of known composition (Ag29LA12)[3-] were covalently conjugated to 6-aminopenicillanic acid, a molecule with a β-lactam backbone. Indeed, the partially conjugated cluster inhibited an Staphylococcus aureus biofilm, in a dose-response manner, with a half-maximal inhibitory concentration IC50 of 2.3 μM, an improvement over 60 times relative to the unconjugated cluster (IC50 = 140 μM). An enhancement of several orders of magnitude over 6-APA alone (unconjugated) was calculated (IC50 = 10 000 μM). Cell wall damage is documented via scanning electron microscopy. A synergistic effect of the conjugate was calculated by the combination index method described by Chou-Talalay. This hybrid nanoantibiotic opens a new front against multidrug-resistant pathogens.
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Affiliation(s)
- Humberto H. Lara
- Department
of Biology and South Texas Center for Emerging Infectious
Diseases and Department of Physics & Astronomy, University of Texas, San Antonio, Texas 78249, United States
| | - David M. Black
- Department
of Biology and South Texas Center for Emerging Infectious
Diseases and Department of Physics & Astronomy, University of Texas, San Antonio, Texas 78249, United States
| | - Christine Moon
- Department
of Chemistry, Los Angeles City College, 855 N Vermont Ave, Los Angeles, California 90029, United States
| | - Elizabeth Orr
- Department
of Chemistry, Los Angeles City College, 855 N Vermont Ave, Los Angeles, California 90029, United States
| | - Priscilla Lopez
- Department
of Biology and South Texas Center for Emerging Infectious
Diseases and Department of Physics & Astronomy, University of Texas, San Antonio, Texas 78249, United States
| | - Marcos M. Alvarez
- Department
of Chemistry, Los Angeles City College, 855 N Vermont Ave, Los Angeles, California 90029, United States
| | - Glen Baghdasarian
- Department
of Chemistry, Los Angeles City College, 855 N Vermont Ave, Los Angeles, California 90029, United States
| | - Jose Lopez-Ribot
- Department
of Biology and South Texas Center for Emerging Infectious
Diseases and Department of Physics & Astronomy, University of Texas, San Antonio, Texas 78249, United States
| | - Robert L. Whetten
- Center
for Materials Interfaces in Research & Applications (MIRA), Applied
Physics and Material Science, Northern Arizona
University, Flagstaff, Arizona 86011, United States
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6
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Zuber G, Weiss E, Chiper M. Biocompatible gold nanoclusters: synthetic strategies and biomedical prospects. NANOTECHNOLOGY 2019; 30:352001. [PMID: 31071693 DOI: 10.1088/1361-6528/ab2088] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The latest advances concerning ultra-small gold nanoparticles (≤2 nm) commonly known as gold nanoclusters (AuNCs) are reviewed and discussed in the context of biological and biomedical applications (labeling, delivery, imaging and therapy). A great diversity of synthetic methods has been developed and optimized aiming to improve the chemical structures and physicochemical properties of the resulting AuNCs. The main synthetic approaches were surveyed with emphasis on methods leading to water-soluble AuNCs since aqueous solutions are the preferred media for biological applications. The most representative and recent experimental results are discussed in relationship to their potential for biomedical applications.
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Affiliation(s)
- Guy Zuber
- Molecular and Pharmaceutical Engineering of Biologics, CNRS-Université de Strasbourg UMR 7242, Boulevard Sebastien Brant, F-67412, Illkirch, France
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7
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Hoque MM, Black DM, Mayer KM, Dass A, Whetten RL. Base Side of Noble Metal Clusters: Efficient Route to Captamino-Gold, Au n(-S(CH 2) 2N(CH 3) 2) p, n = 25-144. J Phys Chem Lett 2019; 10:3307-3311. [PMID: 31067059 DOI: 10.1021/acs.jpclett.9b00886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Monolayer-protected clusters (MPCs), typified by the (Au, Ag)-thiolates, share dimensions and masses with aqueous globular proteins (enzymes), yet efficient bioanalytical methods have not proved applicable to MPC analytics. Here we demonstrate that direct facile ESI(+)MS analysis of MPCs succeeds, at the few-picomol level, for aqueous basic amino-terminated thiolates. Specifically, captamino-gold clusters, Au n(SR) p, wherein -R = -(CH2)2N(CH3)2, are prepared quantitatively via a direct one-phase (aq/EtOH) method and are sprayed under weakly acidic conditions to yield intact 6.8 kDa complexes, ( n, p) = (25, 18), with up to 5 H+ adducts, or 34.6 kDa MPCs (144, 60) at charge state z = 8+. These exceed all prior reports of positive charging of MPCs except for those bearing per-cationized (quat) ligands. pH-mediated reversible phase transfer (aqueous to/from DCM-rich phases) are consistent with peripheral exposure of all tertiary amino groups to solutions. This surprising development opens the way to all manner of modifications or extensions, as well as to advanced analyses inspired by those applied to intact biomolecules.
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Affiliation(s)
- M Mozammel Hoque
- Department of Physics & Astronomy , The University of Texas , San Antonio , Texas 78249 , United States
| | - David M Black
- Department of Physics & Astronomy , The University of Texas , San Antonio , Texas 78249 , United States
| | - Kathryn M Mayer
- Department of Physics & Astronomy , The University of Texas , San Antonio , Texas 78249 , United States
| | - Amala Dass
- Department of Chemistry & Biochemistry , University of Mississippi , Oxford , Mississippi 38677 , United States
| | - Robert L Whetten
- Department of Physics & Astronomy , The University of Texas , San Antonio , Texas 78249 , United States
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8
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McKenzie LC, Zaikova TO, Hutchison JE. Structurally similar triphenylphosphine-stabilized undecagolds, Au11(PPh3)7Cl3 and [Au11(PPh3)8Cl2]Cl, exhibit distinct ligand exchange pathways with glutathione. J Am Chem Soc 2014; 136:13426-35. [PMID: 25171178 PMCID: PMC4183609 DOI: 10.1021/ja5075689] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
![]()
Ligand
exchange is frequently used to introduce new functional
groups on the surface of inorganic nanoparticles or clusters while
preserving the core size. For one of the smallest clusters, triphenylphosphine
(TPP)-stabilized undecagold, there are conflicting reports in the
literature regarding whether core size is retained or significant
growth occurs during exchange with thiol ligands. During an investigation
of these differences in reactivity, two distinct forms of undecagold
were isolated. The X-ray structures of the two forms, Au11(PPh3)7Cl3 and [Au11(PPh3)8Cl2]Cl, differ only in the number
of TPP ligands bound to the core. Syntheses were developed to produce
each of the two forms, and their spectroscopic features correlated
with the structures. Ligand exchange on [Au11(PPh3)8Cl2]Cl yields only small clusters, whereas
exchange on Au11(PPh3)7Cl3 (or mixtures of the two forms) yields the larger Au25 cluster. The distinctive features in the optical spectra of the
two forms made it possible to evaluate which of the cluster forms
were used in the previously published papers and clarify the origin
of the differences in reactivity that had been reported. The results
confirm that reactions of clusters and nanoparticles may be influenced
by small variations in the arrangement of ligands and suggest that
the role of the ligand shell in stabilizing intermediates during ligand
exchange may be essential to preventing particle growth or coalescence.
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Affiliation(s)
- Lallie C McKenzie
- Department of Chemistry and Biochemistry and Materials Science Institute, 1253 University of Oregon , Eugene, Oregon 97403-1253, United States
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9
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Structural and theoretical basis for ligand exchange on thiolate monolayer protected gold nanoclusters. J Am Chem Soc 2012; 134:13316-22. [PMID: 22816317 DOI: 10.1021/ja3032339] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ligand exchange reactions are widely used for imparting new functionality on or integrating nanoparticles into devices. Thiolate-for-thiolate ligand exchange in monolayer protected gold nanoclusters has been used for over a decade; however, a firm structural basis of this reaction has been lacking. Herein, we present the first single-crystal X-ray structure of a partially exchanged Au(102)(p-MBA)(40)(p-BBT)(4) (p-MBA = para-mercaptobenzoic acid, p-BBT = para-bromobenzene thiol) with p-BBT as the incoming ligand. The crystal structure shows that 2 of the 22 symmetry-unique p-MBA ligand sites are partially exchanged to p-BBT under the initial fast kinetics in a 5 min timescale exchange reaction. Each of these ligand-binding sites is bonded to a different solvent-exposed Au atom, suggesting an associative mechanism for the initial ligand exchange. Density functional theory calculations modeling both thiol and thiolate incoming ligands postulate a mechanistic pathway for thiol-based ligand exchange. The discrete modification of a small set of ligand binding sites suggests Au(102)(p-MBA)(44) as a powerful platform for surface chemical engineering.
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10
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Adina-Zada A, Zeczycki TN, Attwood PV. Regulation of the structure and activity of pyruvate carboxylase by acetyl CoA. Arch Biochem Biophys 2012; 519:118-30. [PMID: 22120519 PMCID: PMC3293938 DOI: 10.1016/j.abb.2011.11.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 11/10/2011] [Accepted: 11/10/2011] [Indexed: 12/20/2022]
Abstract
In this review we examine the effects of the allosteric activator, acetyl CoA on both the structure and catalytic activities of pyruvate carboxylase. We describe how the binding of acetyl CoA produces gross changes to the quaternary and tertiary structures of the enzyme that are visible in the electron microscope. These changes serve to stabilize the tetrameric structure of the enzyme. The main locus of activation of the enzyme by acetyl CoA is the biotin carboxylation domain of the enzyme where ATP-cleavage and carboxylation of the biotin prosthetic group occur. As well as enhancing reaction rates, acetyl CoA also enhances the binding of some substrates, especially HCO3-, and there is also a complex interaction with the binding of the cofactor Mg2. The activation of pyruvate carboxylase by acetyl CoA is generally a cooperative processes, although there is a large degree of variability in the degree of cooperativity exhibited by the enzyme from different organisms. The X-ray crystallographic holoenzyme structures of pyruvate carboxylases from Rhizobium etli and Staphylococcus aureus have shown the allosteric acetyl CoA binding domain to be located at the interfaces of the biotin carboxylation and carboxyl transfer and the carboxyl transfer and biotin carboxyl carrier protein domains.
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Affiliation(s)
- Abdussalam Adina-Zada
- School of Biomedical , Biomolecular and Chemical Sciences, University of Western Australia, Crawley, WA6009, Australia
| | - Tonya N. Zeczycki
- Department of Biochemistry, University of Wisconsin, Madison, WI 53726, USA
| | - Paul V. Attwood
- School of Biomedical , Biomolecular and Chemical Sciences, University of Western Australia, Crawley, WA6009, Australia
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11
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Abstract
The scientific study of gold nanoparticles (typically 1-100 nm) has spanned more than 150 years since Faraday's time and will apparently last longer. This review will focus on a special type of ultrasmall (<2 nm) yet robust gold nanoparticles that are protected by thiolates, so-called gold thiolate nanoclusters, denoted as Au(n)(SR)(m) (where, n and m represent the number of gold atoms and thiolate ligands, respectively). Despite the past fifteen years' intense work on Au(n)(SR)(m) nanoclusters, there is still a tremendous amount of science that is not yet understood, which is mainly hampered by the unavailability of atomically precise Au(n)(SR)(m) clusters and by their unknown structures. Nonetheless, recent research advances have opened an avenue to achieving the precise control of Au(n)(SR)(m) nanoclusters at the ultimate atomic level. The successful structural determination of Au(102)(SPhCOOH)(44) and [Au(25)(SCH(2)CH(2)Ph)(18)](q) (q = -1, 0) by X-ray crystallography has shed some light on the unique atomic packing structure adopted in these gold thiolate nanoclusters, and has also permitted a precise correlation of their structure with properties, including electronic, optical and magnetic properties. Some exciting research is anticipated to take place in the next few years and may stimulate a long-lasting and wider scientific and technological interest in this special type of Au nanoparticles.
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Affiliation(s)
- Rongchao Jin
- Carnegie Mellon University, Department of Chemistry, Pittsburgh, PA 15213, USA.
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12
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Ackerson CJ, Powell RD, Hainfeld JF. Site-specific biomolecule labeling with gold clusters. Methods Enzymol 2010; 481:195-230. [PMID: 20887859 DOI: 10.1016/s0076-6879(10)81009-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: linker-mediated bioconjugation, direct gold-biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (His)-tagged proteins.
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13
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Chapter 3 History of the STEM at Brookhaven National Laboratory. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s1076-5670(09)59003-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Sousa AA, Aronova MA, Kim YC, Dorward LM, Zhang G, Leapman RD. Reprint of "On the feasibility of visualizing ultrasmall gold labels in biological specimens by STEM tomography" [J. Struct. Biol. 159 (2007) 507-522]. J Struct Biol 2008; 161:336-51. [PMID: 18342743 DOI: 10.1016/s1047-8477(08)00063-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 11/25/2022]
Abstract
Labeling with heavy atom clusters attached to antibody fragments is an attractive technique for determining the 3D distribution of specific proteins in cells using electron tomography. However, the small size of the labels makes them very difficult to detect by conventional bright-field electron tomography. Here, we evaluate quantitative scanning transmission electron microscopy (STEM) at a beam voltage of 300kV for detecting 11-gold atom clusters (Undecagold) and 1.4nm-diameter nanoparticles (Nanogold) for a variety of specimens and imaging conditions. STEM images as well as tomographic tilt series are simulated by means of the NIST Elastic-Scattering Cross-Section Database for gold clusters embedded in carbon. The simulations indicate that the visibility in 2D of Undecagold clusters in a homogeneous matrix is maximized for low inner collection semi-angles of the STEM annular dark-field detector (15-20mrad). Furthermore, our calculations show that the visibility of Undecagold in 3D reconstructions is significantly higher than in 2D images for an inhomogeneous matrix corresponding to fluctuations in local density. The measurements demonstrate that it is possible to detect Nanogold particles in plastic sections of tissue freeze-substituted in the presence of osmium. STEM tomography has the potential to localize specific proteins in permeabilized cells using antibody fragments tagged with small heavy atom clusters. Our quantitative analysis provides a framework for determining the detection limits and optimal experimental conditions for localizing these small clusters.
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Affiliation(s)
- A A Sousa
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Building 13, Room 3N17, 13 South Drive, Bethesda, MD 20892-5766, USA
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15
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Mercogliano CP, DeRosier DJ. Concatenated metallothionein as a clonable gold label for electron microscopy. J Struct Biol 2007; 160:70-82. [PMID: 17692533 PMCID: PMC2034524 DOI: 10.1016/j.jsb.2007.06.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 06/26/2007] [Accepted: 06/28/2007] [Indexed: 11/21/2022]
Abstract
Localization of proteins in cells or complexes using electron microscopy has mainly relied upon the use of heavy metal clusters, which can be difficult to direct to sites of interest. For this reason, we would like to develop a clonable tag analogous to the clonable fluorescent tags common to light microscopy. Instead of fluorescing, such a tag would initiate formation of a heavy metal cluster. To test the feasibility of such a tag, we exploited the metal-binding protein, metallothionein (MT). We created a chimeric protein by fusing one or two copies of the MT gene to the gene for maltose binding protein. These chimeric proteins bound many gold atoms, with a conservative value of 16 gold atoms per copy of metallothionein. Visualization of gold-labeled fusion proteins by scanning electron microscopy required one copy of metallothionein while transmission electron microscopy required two copies. Images of frozen-hydrated samples of simple complexes made with anti-MBP antibodies hint at the usefulness of this method.
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16
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Sousa AA, Aronova MA, Kim YC, Dorward LM, Zhang G, Leapman RD. On the feasibility of visualizing ultrasmall gold labels in biological specimens by STEM tomography. J Struct Biol 2007; 159:507-22. [PMID: 17689263 PMCID: PMC2748118 DOI: 10.1016/j.jsb.2007.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 10/23/2022]
Abstract
Labeling with heavy atom clusters attached to antibody fragments is an attractive technique for determining the 3D distribution of specific proteins in cells using electron tomography. However, the small size of the labels makes them very difficult to detect by conventional bright-field electron tomography. Here, we evaluate quantitative scanning transmission electron microscopy (STEM) at a beam voltage of 300 kV for detecting 11-gold atom clusters (Undecagold) and 1.4 nm-diameter nanoparticles (Nanogold) for a variety of specimens and imaging conditions. STEM images as well as tomographic tilt series are simulated by means of the NIST Elastic-Scattering Cross-Section Database for gold clusters embedded in carbon. The simulations indicate that the visibility in 2D of Undecagold clusters in a homogeneous matrix is maximized for low inner collection semi-angles of the STEM annular dark-field detector (15-20 mrad). Furthermore, our calculations show that the visibility of Undecagold in 3D reconstructions is significantly higher than in 2D images for an inhomogeneous matrix corresponding to fluctuations in local density. The measurements demonstrate that it is possible to detect Nanogold particles in plastic sections of tissue freeze-substituted in the presence of osmium. STEM tomography has the potential to localize specific proteins in permeabilized cells using antibody fragments tagged with small heavy atom clusters. Our quantitative analysis provides a framework for determining the detection limits and optimal experimental conditions for localizing these small clusters.
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Affiliation(s)
- A. A. Sousa
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - M. A. Aronova
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Y. C. Kim
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, MD 20892, USA
| | - L. M. Dorward
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - G. Zhang
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - R. D. Leapman
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
- Correspondence: Dr. Richard D. Leapman, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bldg. 13, Rm. 3N17, 13 South Drive, Bethesda, MD 20892-5766, Tel: 301-496-2599, Fax: 301-435-4699,
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17
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Hall KP, Mingos DMP. Homo- and Heteronuclear Cluster Compounds of Gold. PROGRESS IN INORGANIC CHEMISTRY 2007. [DOI: 10.1002/9780470166338.ch3] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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18
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Ackerson CJ, Jadzinsky PD, Jensen GJ, Kornberg RD. Rigid, specific, and discrete gold nanoparticle/antibody conjugates. J Am Chem Soc 2006; 128:2635-40. [PMID: 16492049 DOI: 10.1021/ja0555668] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A general method of rigid, specific labeling of proteins with gold clusters has been devised. The method relies on the conjugation of a glutathione monolayer-protected gold cluster (MPC) with a single chain Fv antibody fragment (scFv), mutated to present an exposed cysteine residue. Efficient formation of a gold-thiolate bond between the MPC and scFv depends on activation of the gold cluster by chemical oxidation. Once formed, the MPC-scFv conjugate is treated with a reductant to quench cluster reactivity. The procedure has been performed with an MPC with an average Au(71) core and an scFv directed against a tetrameric protein, the influenza neuraminidase. A complex of the MPC-scFv conjugate with the neuraminidase was isolated, and the presence of four gold clusters was verified by cryoelectron microscopy.
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Affiliation(s)
- Christopher J Ackerson
- Department of Structural Biology, Stanford University School of Medicine, California 94305, USA
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19
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Tartaj P, Morales MP, Veintemillas-Verdaguer S, Gonzalez-Carreño T, Serna CJ. chapter 5 Synthesis, Properties and Biomedical Applications of Magnetic Nanoparticles. HANDBOOK OF MAGNETIC MATERIALS 2006. [DOI: 10.1016/s1567-2719(05)16005-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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20
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Mercogliano CP, DeRosier DJ. Gold Nanocluster Formation using Metallothionein: Mass Spectrometry and Electron Microscopy. J Mol Biol 2006; 355:211-23. [PMID: 16305802 DOI: 10.1016/j.jmb.2005.10.026] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 10/04/2005] [Accepted: 10/13/2005] [Indexed: 11/29/2022]
Abstract
Clonable contrasting agents for light microscopy, such as green fluorescent protein, have revolutionized biology, but few such agents have been developed for transmission electron microscopy (TEM). As an attempt to develop a novel clonable contrasting agent for TEM, we have evaluated metallothionein, a small metal-binding protein, reacted with aurothiomalate, an anti-arthritic gold compound. Electro spray ionization and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry measurements show a distribution of gold atoms bound to individual metallothionein molecules. Unlike previous reports, these data show gold binding occurred as the addition of single atoms without retention of additional ligands. Moreover, under certain conditions, MALDI spectra show gold binding ratios of greater than 1:1 with the cysteine residues of metallothionein. Together, this may hint at a gold-binding mechanism similar to gold nanocluster formation. Finally, metallothionein-gold complexes visualized in the TEM show a range of sizes similar to those used as current TEM labels, and show the potential of the protein as a clonable TEM label in which the gold cluster is grown on the label, thereby circumventing the problems associated with attaching gold clusters.
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Niemeyer CM. Nanoparticles, Proteins, and Nucleic Acids: Biotechnology Meets Materials Science. Angew Chem Int Ed Engl 2001; 40:4128-4158. [DOI: 10.1002/1521-3773(20011119)40:22<4128::aid-anie4128>3.0.co;2-s] [Citation(s) in RCA: 2006] [Impact Index Per Article: 87.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2001] [Indexed: 01/04/2023]
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Abstract
In the scanning transmission electron microscope (STEM) an electron beam of a few angstroms diameter is raster scanned over a thin sample and the scattered electrons are sequentially measured for each sample element irradiated. The mass, the elemental composition and the structure of a protein can be simultaneously assessed if all detector systems of the STEM are used. Aspects affecting the accuracy of the mass measurement technique and the demands placed on the instrument's dark-field detector system are outlined. In addition, the influences of some sample preparation techniques are noted and the mass-loss induced at ambient temperatures by the incidence of 80kV electrons on various biological samples is reported. Finally, the importance of the STEM for the structural analysis of proteins is documented by examples.
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Affiliation(s)
- S A Müller
- Maurice E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
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25
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Abstract
Undecagold cluster labeling of reactive cysteine residues in numerous proteins has allowed the labeled sites to be identified by electron microscopy, providing high-resolution information on the location and orientation of subunits in oligomeric enzymes, virus capsids, crystalline sheets of membrane proteins, and muscle thin filaments. The range of applications of undecagold cluster labeling has been greatly extended by the availability of site-directed mutagenesis to introduce cysteine residues at sites of interest. In this paper I discuss factors that can influence the extent and specificity of labeling, methods for biochemical analysis of undecagold-labeled proteins, and the effects of undecagold cluster labeling on biological activity.
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Affiliation(s)
- D Safer
- Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6085, USA
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26
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Abstract
"Greengold" is a large metallic cluster thought to contain 75 gold atoms in a compact 1.4-nm-diameter core surrounded by an organic shell. Scanning transmission electron microscope imaging shows uniform mass and size distributions with an apparent mass of 24 kDa, unaffected by radiation damage. The signal-to-noise ratio is adequate for visualization at low dose and in the presence of a relatively thick biological matrix. Under some conditions these clusters have a slight tendency to form linear chains and 2-D hexagonal arrays with a spacing of 2.6 nm. The parameters presented permit estimation of the feasibility of proposed labeling experiments.
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Affiliation(s)
- J S Wall
- Biology Department, Brookhaven National Laboratory, Building 463, Upton, New York 11973, USA
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Niemeyer CM, Bürger W, Peplies J. Kovalente DNA-Streptavidin-Konjugate als Bausteine für neuartige biometallische Nanostrukturen. Angew Chem Int Ed Engl 1998. [DOI: 10.1002/(sici)1521-3757(19980817)110:16<2391::aid-ange2391>3.0.co;2-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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28
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Wall JS, Hainfeld JF, Simon MN. Scanning transmission electron microscopy of nuclear structures. Methods Cell Biol 1997; 53:139-64. [PMID: 9348508 DOI: 10.1016/s0091-679x(08)60878-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J S Wall
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973, USA
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29
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Abstract
Colloidal gold is the most widely used electron dense marker in biological electron microscopy. The development of procedures for making gold particles of very defined sizes has made double or even multiple labelling possible using gold of two or more different sizes. Lately a new type of electron dense marker has been developed consisting of ligand-stabilized metal atom clusters rather than colloidal particles. The differences between these two types of markers are highlighted and the advantages of using metal atom clusters for immuno labelling of certain biological specimens are discussed. Possible methods of distinguishing two such cluster labels in double labelling experiments are reviewed.
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Affiliation(s)
- P J Koeck
- Karolinska Institute, Department of Bioscience, Huddinge, Sweden
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31
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Vener AV, Evtushenko OA, Baykov AA. Use of biotinylated inorganic pyrophosphatase for detection of biotin bound to solid support. Anal Biochem 1990; 191:65-9. [PMID: 1964028 DOI: 10.1016/0003-2697(90)90388-p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A colorimetric procedure to detect biotin bound to microtiter plates with a sensitivity down to 10(-16) mol was developed using biotinylated inorganic pyrophosphatase of Escherichia coli. Reaction of pyrophosphatase with 1 mM N-biotinyl-6-aminocaproic acid N-hydroxy-sulfonosuccinimide ester yielded a stable 87% active enzyme containing 5.6 mol biotin/mol. In the measurements of human immunoglobulin G, a biotinylated pyrophosphatase.streptavidin complex provided a sensitivity superior to that of conventional enzyme immunoassay due to low nonspecific binding. The new procedure was also more sensitive compared with that using biotinylated alkaline phosphatase. Together with high thermostability of pyrophosphatase and its substrate, low background staining allowed measurement of enzymatic activity to be performed at 60 degrees C for 4 h resulting in a marked increase in assay sensitivity.
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Affiliation(s)
- A V Vener
- A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, USSR
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32
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33
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Abstract
Colloidal gold is easily prepared, and readily adsorbs to a number of immunoreagents and other proteins for a wide variety of uses for neuronal visualization. Gold probes serve a role as immunolabels for both light and electron microscopy. As an ultrastructural immunocytochemical marker for detection of proteins, peptides or amino acids, gold can be used for immunostaining thick or thin sections prior to embedding, or for immunostaining ultrathin sections after embedding tissue in conventional or unusual embedding matrices. By virtue of its particulate nature, gold as an immunolabel facilitates a semi-quantitative analysis of relative antigen densities on ultrathin sections. Various combinations of different size gold particles or dual immunolabelling with enzymatic immunolabels together with colloidal gold or silver-intensified gold serve well for ultrastructural immunocytochemical localization of two antigens in the same tissue section. Colloidal gold can be detected with light microscopy, transmission and scanning electron microscopy, and with confocal laser microscopy. Silver intensification allows detection of gold at both the light and electron microscope level, and increases the sensitivity of immunogold procedures. Colloidal gold is useful as a tracer for physiological studies of transport and internalization in neurons in vivo and in vitro; computer-assisted video imaging techniques allow detection and tracking of single gold particles in living cells.
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Affiliation(s)
- A N van den Pol
- Section of Neurosurgery, Yale University School of Medicine, New Haven, Ct. 06510
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34
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Däkena P, Rohde M, Dimroth P, Mayer F. Oxaloacetate decarboxylase fromKlebsiella pneumoniae: size and shape of the enzyme, and localization of its prosthetic biotin group by electron microscopic affinity labeling. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb02794.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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35
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Abstract
The Fab' fragments of antibodies can be combined with eleven gold-atom clusters to produce the smallest gold-conjugated antibody probes yet developed.
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Affiliation(s)
- J F Hainfeld
- Brookhaven National Laboratory, Biology Department, Upton, New York 11973
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36
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Affiliation(s)
- M Wilchek
- Department of Biophysics, Weizmann Institute of Science, Rehovot, Israel
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37
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Abstract
A general method has been developed to make the smallest gold-conjugated antibody label yet developed for electron microscopy. It should have wide application in domainal mapping of single molecules or in pinpointing specific molecules, sites, or sequences in supramolecular complexes. It permits electron microscopic visualization of single antigen-binding antibody fragments (Fab') by covalently linking an 11-atom gold cluster to a specific residue on each Fab' such that the antigenic specificity and capacity are preserved. The distance of the gold cluster from the antigen is a maximum of 5.0 nanometers when the undecagold-Fab' probe is used as an immunolabel.
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38
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Monson KL, Wall JS, Hainfeld JF. Visibility and stability of a 12-tungsten atom complex in the scanning transmission electron microscope. Ultramicroscopy 1987; 21:147-56. [PMID: 3564170 DOI: 10.1016/0304-3991(87)90081-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A complex consisting of 12 tungsten atoms has been studied in terms of signal-to-noise (S/N) and dose response in the scanning transmission electron microscope (STEM), to evaluate its suitability for use as a approximately 1 nm resolution biological label. Molecular weight of the complex was measured as a function of radius of integration, and results were in agreement with the calculated formula weight. S/N was highest at the lowest radius of integration (0.25 nm), and decreased monotonically with increasing radius. The complex was clearly visible at a dose of 4 X 10(3) e/nm2, and exhibited negligible mass loss (approximately 8%) after an accumulated dose of 1.28 X 10(5) e/nm2. Beam-induced motion was small, 0.46 nm rms after 4 X 10(4) e/nm2. Some intensity fluctuations were observed between successive scans of the same clusters, for which a diffraction-based explanation is advanced. Upon suitable functionalization, the tungsten complex is expected to complement the undecagold cluster already in use for site-specific labeling.
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39
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Hainfeld JF, Wall JS. Mapping the domains of molecules and complexes by mass and heavy atom loading. Ann N Y Acad Sci 1986; 483:181-7. [PMID: 3471124 DOI: 10.1111/j.1749-6632.1986.tb34518.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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40
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Pfahler WH, Reimann M, Munz E. A biotin-avidin amplified enzyme immunoassay for detection and quantitation of orthopox virus camel antibodies in dromedaries. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1986; 33:477-84. [PMID: 3028013 DOI: 10.1111/j.1439-0450.1986.tb00059.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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41
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Attwood PV, Mayer F, Wallace JC. Avidin as a probe of the conformational changes induced in pyruvate carboxylase by acetyl-CoA and pyruvate. FEBS Lett 1986; 203:191-6. [PMID: 3732509 DOI: 10.1016/0014-5793(86)80740-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sheep liver pyruvate carboxylase was mixed with avidin at a molar ratio of 1:1 in the presence of various combinations of the components of the assay systems required for either the acetyl-CoA-dependent or the acetyl-CoA-independent activity and negatively stained samples were examined by electron microscopy. Significant numbers of chain-like polymers of enzyme-avidin complexes were evident only when acetyl-CoA or high levels of pyruvate were present in the media. Similar results were also obtained for chicken liver pyruvate carboxylase despite this enzyme's almost complete lack of acetyl-CoA-independent activity. Thus, although acetyl-CoA and high concentrations of pyruvate may induce pyruvate carboxylase to adopt a 'tight' tetrahedron-like conformation which can interact with avidin to form chains, this structural change alone does not result in an enzymic form that is maximally active. This suggests that the allosteric activation of pyruvate carboxylase by acetyl-CoA is attributable, at least in part to more subtle conformational changes; especially in the case of the chicken enzyme.
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42
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Safer D, Bolinger L, Leigh JS. Undecagold clusters for site-specific labeling of biological macromolecules: simplified preparation and model applications. J Inorg Biochem 1986; 26:77-91. [PMID: 3958709 DOI: 10.1016/0162-0134(86)80001-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We report simple and rapid procedures for the synthesis of a variety of stable, water-soluble undecagold cluster, and model applications of a thiol-reactive gold cluster for the specific labeling of cysteine residues in proteins.
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43
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Johnson KA. Scanning transmission electron microscopy of dynein arms. Ann N Y Acad Sci 1984; 438:217-23. [PMID: 6242011 DOI: 10.1111/j.1749-6632.1984.tb38288.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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44
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Yang H, Reardon JE, Frey PA. Synthesis of undecagold cluster molecules as biochemical labeling reagents. 2. Bromoacetyl and maleimido undecagold clusters. Biochemistry 1984; 23:3857-62. [PMID: 6487582 DOI: 10.1021/bi00312a010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Derivatives of heptakis[4,4',4"-phosphinidynetris(benzenemethanamine) ]undecagold, 1, molecular formula Au11(CN)3[P(C6H4CH2NH3)]7, are described. These include undecagold complexes with a single free primary amino group, a single bromoacetyl group, and a single maleimido group per molecule. Hydrolysis of mono(N-phthalyl)icosa(N-acetyl)-1 at pH 3.2 and 46 degrees C under anaerobic conditions and in the presence of NaBH3CN produces icosa(N-acetyl)-1. Partial acylation of 1 with 1.3 equiv of 2,3-dimethylmaleic anhydride followed by complete acetylation with acetic anhydride produces a mixture consisting largely of mono- and bis(dimethylmaleyl)peracetyl-1. Hydrolysis of 2,3-dimethylmaleimides at pH 3.2 for 1 at 25 degrees C produces a mixture of icosa(N-acetyl)-1, with a single free amino group, and nondea(N-acetyl)-1. This mixture can be quantitatively separated by cation-exchange chromatography at pH 7, giving homogeneous icosa(N-acetyl)-1 in an overall yield of 55%. Icosa(N-acetyl)-1 serves as the starting material for the synthesis of the alkylating derivatives mono(N-bromoacetyl)icosa(N-acetyl)-1 and mono[N-(p-maleimidobenzoyl)]icosa(N-acetyl)-1. These derivatives can be used for alkylating proteins in preparation for electron microscopy.
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45
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Reardon JE, Frey PA. Synthesis of undecagold cluster molecules as biochemical labeling reagents. 1. Monoacyl and mono[N-(succinimidooxy)succinyl] undecagold clusters. Biochemistry 1984; 23:3849-56. [PMID: 6487581 DOI: 10.1021/bi00312a009] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper describes the synthesis and characterization of succinyl, phthalyl, and N-(succinimidooxy)-succinyl derivatives of the undecagold cluster complex tricyanoheptakis[4,4',4"-phosphinidynetris(benzenemethana mine)]undecagold, 1, molecular formula Au11(CN)3[P(C6-H4CH2NH2)3]7. These are useful as electron-dense reagents for labeling biological structures in preparation for electron microscopic analysis. Limited reaction of 1 with succinic or phthalic anhydrides produces a mixture of mono-, bis-, etc. (N-succinyl)-1 or (N-phthalyl)-1, which can be separated by anion-exchange chromatography at pH 11.5. Yields of monoacylated derivatives can be maximized by controlling the ratio of succinic or phthalic anhydride to 1. The remaining 20 primary amino groups can be dialkylated or acetylated, blocking their participation in further chemical modifications of the carboxylic functional group introduced in the succinylation or phthalylation of 1. These carboxyl groups can be activated as N-hydroxysuccinimido esters, which are acylating derivatives of 1. An example is mono[N-(succinimidooxy)-succinyl]icosa(N,N-dimethyl)-1 whose synthesis is described. Bis- and tris(N-succinyl) and -(N-phthalyl) derivatives of 1 are also produced and isolated in usable quantities.
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Yang H, Frey PA. Synthesis of undecagold cluster molecules as biochemical labeling reagents. 3. Dimeric cluster with a single reactive amino group. Biochemistry 1984; 23:3863-8. [PMID: 6487583 DOI: 10.1021/bi00312a011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The synthesis and characterization of a dimeric derivative of the undecagold cluster complex Au11(CN)3[P-(C6H4CH2NH2)3]7, 1, are described. The dimer, 2, consists of cross-linked molecules of 1 in which 41 of the 42 amino groups are acylated, leaving a single free amino group per dimer. This amino group is reactive and can be used to prepare derivatives of 2 for use in labeling biological macromolecules in preparation for electron microscopic analysis. Limited acylation of 1 by 1.3 equiv of citraconic anhydride in aqueous solution, followed by extensive acylation with acetic anhydride at pH 7-7.5, leads to a mixture of monomeric and dimeric products. Hydrolytic removal of N-citraconyl groups at pH 3.2 unmasks a few amino groups. Cation-exchange chromatography at pH 7 separates the products into three main groups, species containing one, two, or three free amino groups, in overall yields of 33%, 28%, and 15%, respectively. The monoamino species consist mainly of 2 and a monomeric product, which are separated by gel exclusion chromatography. 2 migrates as a dimer upon polyacrylamide gel electrophoresis in sodium dodecyl sulfate, and it contains a single free amino group, detectable by its ion-exchange behavior as a monocation at pH 7 and by its reactivity with [14C]phthalic anhydride.
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47
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Elo HA, Korpela J. The occurrence and production of avidin: a new conception of the high-affinity biotin-binding protein. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1984; 78:15-20. [PMID: 6086227 DOI: 10.1016/0305-0491(84)90137-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The production of avidin, a high-affinity biotin-binding egg-white protein, is not restricted to the avian, amphibian and reptilian oviducts. In the acute phase of inflammation, avidin is synthesized and secreted by various injured tissues in the domestic fowl, both male and female. Also in other avian species and a lizard, injured tissues produce an avidin-like biotin-binding factor. The non-oviductal production of avidin in domestic fowl has a great variety of inducers, for example acute inflammation caused by mechanical or thermal tissue injury, septic bacterial infection and (toxic) drugs, and even retrovirus-induced cell transformation. In culture, chicken embryo fibroblasts and yolk sac macrophages synthesize and secrete avidin. Besides the albumen, avidin may act as an antibacterial protein also in the tissues.
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Wall J, Hainfeld J, Haschemeyer RH, Mosesson MW. Analysis of human fibrinogen by scanning transmission electron microscopy. Ann N Y Acad Sci 1983; 408:164-79. [PMID: 6346984 DOI: 10.1111/j.1749-6632.1983.tb23243.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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50
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Johannssen W, Attwood PV, Wallace JC, Keech DB. Localisation of the active site of pyruvate carboxylase by electron microscopic examination of avidin-enzyme complexes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1983; 133:201-6. [PMID: 6189712 DOI: 10.1111/j.1432-1033.1983.tb07448.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Negatively stained enzyme-avidin complexes, seen at different stages of the titration of the biotin-binding sites on avidin with chicken liver pyruvate carboxylase, have been studied using electron microscopy. Formation of linear, unbranched polymers of the enzyme-avidin complex is seen to occur when the ratio of avidin to enzyme is between 2:1 and 1:2; beyond these limits only single enzyme tetramers are visible. The single avidin molecules observed seem to have a cuboid structure. The orientation and dimensions of the enzyme tetramers within the polymers indicate that the tetrahedron-like structure, observed in the single molecules, has been preserved. From the structure of the polymers and the observation of single enzyme-avidin complexes, we deduce that the biotin groups on the enzyme are located on the external faces of each subunit close to, and probably within 3 nm of, the intersubunit junction.
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