A high-performance neutron diffractometer for biological crystallography (BIX-3)

2002 ◽  
Vol 35 (1) ◽  
pp. 34-40 ◽  
Author(s):  
I. Tanaka ◽  
K. Kurihara ◽  
T. Chatake ◽  
N. Niimura
Keyword(s):  
High Performance ◽  
Signal To Noise Ratio ◽  
Neutron Imaging ◽  
Bragg Diffraction ◽  
Imaging Plate ◽  
Biological Macromolecules ◽  
Hydrogen Atoms ◽  
Neutron Diffractometer ◽  
Technical Innovations ◽  
Neutron Protein Crystallography

A high-performance neutron diffractometer for biological crystallography (BIX-3) has been constructed at JRR-3M in the Japan Atomic Energy Research Institute (JAERI) in order to determine the hydrogen-atom positions in biological macromolecules. It uses several recent technical innovations, such as a neutron imaging plate and an elastically bent silicon monochromator developed by the authors. These have made it possible to realise a compact vertical arrangement of the diffractometer. Diffraction data have been collected from the proteins rubredoxin and myoglobin in about one month, to a resolution of 1.5 Å. The data were good enough to identify the hydrogen atoms with high accuracy. By adopting a crystal-step scan method for measuring Bragg diffraction intensities, the signal-to-noise ratio was much better than that of the Laue method. This shows that BIX-3 is one of the best-performing machines for neutron protein crystallography in the world today.

High resolution neutron protein crystallography. Hydrogen and hydration in proteins

2003 ◽  
Vol 218 (2) ◽  
Author(s):  
N. Niimura ◽  
T. Chatake ◽  
A. Ostermann ◽  
K. Kurihara ◽  
I. Tanaka
Keyword(s):  
High Resolution ◽  
Dynamical Behavior ◽  
Protein Crystallography ◽  
Neutron Imaging ◽  
Imaging Plate ◽  
Biological Macromolecules ◽  
Hydrogen Atoms ◽  
Neutron Diffractometer ◽  
Neutron Protein Crystallography ◽  
Acidic Hydrogen

AbstractNeutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, and the development of the neutron imaging plate (NIP) became a breakthrough event in neutron protein crystallography. The general features of the NIP are reviewed. A high resolution neutron diffractometer dedicated to biological macromolecules (BIX-3) with the NIP has been constructed at Japan Atomic Energy Research Institute and this has enabled 1.5 Å resolution structural analyses of several proteins to be carried out. The specifications of BIX-3 and LADI (a quasi-Laue type diffractometer installed in the Institut Laue-Langevin) are compared. The crystal structures of myoglobin, wild type rubredoxin and a mutant of rubredoxin have been carried out using BIX-3. From these studies, several topics, such as the location of hydrogen bonds and certain acidic hydrogen atoms, the identification of methyl hydrogen atoms, details of H/D exchange and dynamical behavior of hydration structures have been investigated, and important information has been extracted from the structural results. Finally, a systematic procedure to grow large single crystals of proteins or nucleic acids is described.

A neutron diffractometer for biological macromolecules using neutron imaging plates

1997 ◽  
Vol 241-243 ◽  
pp. 207-209 ◽  
Author(s):  
S Fujiwara ◽  
Y Karasawa ◽  
I Tanaka ◽  
Y Minezaki ◽  
Y Yonezawa ◽  
...  
Keyword(s):  
Neutron Imaging ◽  
Biological Macromolecules ◽  
Neutron Diffractometer ◽  
Imaging Plates

An upgraded neutron diffractometer (BIX-IM) for macromolecules with a neutron imaging plate

1999 ◽  
Vol 60 (8-9) ◽  
pp. 1623-1626 ◽  
Author(s):  
I Tanaka ◽  
K Kurihara ◽  
Y Haga ◽  
Y Minezaki ◽  
S Fujiwara ◽  
...  
Keyword(s):  
Neutron Imaging ◽  
Imaging Plate ◽  
Neutron Diffractometer

BioDiff - a neutron diffractometer for protein crystallography

2014 ◽  
Vol 70 (a1) ◽  
pp. C1215-C1215
Author(s):  
Tobias Schrader ◽  
Andreas Ostermann ◽  
Michael Monkenbusch ◽  
Bernhard Laatsch ◽  
Philipp Jüttner ◽  
...  
Keyword(s):  
Neutron Beam ◽  
Pyrolytic Graphite ◽  
Ccd Camera ◽  
Background Level ◽  
Neutron Imaging ◽  
Imaging Plate ◽  
Active Centre ◽  
Joint Project ◽  
Neutron Diffractometer

The research reactor Heinz Maier-Leibnitz (FRM II) is a modern high flux neutron source which feeds some 30 state of the art neutron beam instruments. Currently 24 are operational, others in commissioning or under construction. The newly built neutron single crystal diffractometer BIODIFF is especially designed to collect data from crystals with large unit cells. The main field of application is the structural analysis of proteins, especially the determination of hydrogen atom positions. BIODIFF is a joint project of the Jülich Centre for Neutron Science (JCNS) and the FRM II. Typical scientific questions addressed are the determination of protonation states of amino acid side chains (see e. g. [1,2]) and the characterization of the hydrogen bonding network between the protein active centre and an inhibitor or substrate. BIODIFF is designed as a monochromatic instrument. By using a highly orientated pyrolytic graphite monochromator (PG002) the diffractometer is able to operate in the wavelength range of 2.4 Å to about 5.6 Å. Contaminations of higher order wavelengths are removed by a neutron velocity selector. To cover a large solid angle the main detector of BIODIFF consists of a neutron imaging plate in a cylindrical geometry with online read-out capability. A fast Li/ZnS scintillator CCD camera is available for additional detection abilities. An optical CCD-camera pointing at the sample position is used to quickly align the crystal with respect to the neutron beam. The main advantage of BIODIFF is the possibility to adapt the wavelength to the size of the unit cell of the sample crystal while operating with a clean monochromatic beam that keeps the background level low. BIODIFF is equipped with a standard Oxford Cryosystem "Cryostream 700+" which allows measurements in the temperature regime from 90 K up to 500 K (see Figure underneath).

Looking for Hydrogen Atoms: Neutron Crystallography Provides Novel Insights Into Protein Structure and Function

2014 ◽  
Vol 67 (12) ◽  
pp. 1751 ◽  
Author(s):  
Emily A. Golden ◽  
Alice Vrielink
Keyword(s):  
Protein Structures ◽  
Biological Macromolecules ◽  
Binding Affinities ◽  
Hydrogen Atoms ◽  
Hydronium Ions ◽  
Direct Localization ◽  
Neutron Protein Crystallography ◽  
And Function ◽  
Neutron Crystallography

Neutron crystallography allows direct localization of hydrogen positions in biological macromolecules. Within enzymes, hydrogen atoms play a pivotal role in catalysis. Recent advances in instrumentation and sample preparation have helped to overcome the difficulties of performing neutron diffraction experiments on protein crystals. The application of neutron macromolecular crystallography to a growing number of proteins has yielded novel structural insights. The ability to accurately position water molecules, hydronium ions, and hydrogen atoms within protein structures has helped in the study of low-barrier hydrogen bonds and hydrogen-bonding networks. The determination of protonation states of protein side chains, substrates, and inhibitors in the context of the macromolecule has provided important insights into enzyme chemistry and ligand binding affinities, which can assist in the design of potent therapeutic agents. In this review, we give an overview of the method and highlight advances in knowledge attained through the application of neutron protein crystallography.

Preparation and Characterization of the High Molecular Weight [3H]Hyaluronic Acid

1992 ◽  
Vol 57 (10) ◽  
pp. 2151-2156 ◽  
Author(s):  
Peter Chabreček ◽  
Ladislav Šoltés ◽  
Hynek Hradec ◽  
Jiří Filip ◽  
Eduard Orviský
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
High Molecular Weight ◽  
Methyl Bromide ◽  
High Performance ◽  
Hydrogen Atoms ◽  
Isolation And Characterization ◽  
Labelling Procedure ◽  
Enzymatic Depolymerization

Two methods for the preparation of high molecular weight [3H]hyaluronic acid were investigated. In the first one, hydrogen atoms in the molecule were replaced by tritium. This isotopic substitution was performed in aqueous solution using Pd/CaCO3 as the catalyst. In the second method, the high molecular weight hyaluronic acid was alkylated with [3H]methyl bromide in liquid ammonia at a temperature of -33.5 °C. High-performance gel permeation chromatographic separation method was used for the isolation and characterization of the high molecular weight [3H]hyaluronic acid. Molecular weight parameters for the labelled biopolymers were Mw = 128 kDa, Mw/Mn = 1.88 (first method) and Mw = 268 kDa, Mw/Mn = 1.55 (second method). The high molecular weight [3H]hyaluronic acid having Mw = 268 kDa was degraded further by specific hyaluronidase. Products of the enzymatic depolymerization were observed to be identical for both, labelled and cold biopolymer. This finding indicates that the described labelling procedure using [3H]methyl bromide does not induce any major structural rearrangements in the molecule.

A High-Performance Signal Processing System for Monopulse Tracking Radar

2011 ◽  
Vol 383-390 ◽  
pp. 471-475
Author(s):  
Yong Bin Hong ◽  
Cheng Fa Xu ◽  
Mei Guo Gao ◽  
Li Zhi Zhao
Keyword(s):  
Signal Processing ◽  
High Performance ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Processing System ◽  
Digital Signal ◽  
Radar Signal ◽  
Signal Processing System ◽  
Parallel Pipelined ◽  
Tracking Radar

A radar signal processing system characterizing high instantaneous dynamic range and low system latency is designed based on a specifically developed signal processing platform. Instantaneous dynamic range loss is a critical problem when digital signal processing is performed on fixed-point FPGAs. In this paper, the problem is well resolved by increasing the wordlength according to signal-to-noise ratio (SNR) gain of the algorithms through the data path. The distinctive software structure featuring parallel pipelined processing and “data flow drive” reduces the system latency to one coherent processing interval (CPI), which significantly improves the maximum tracking angular velocity of the monopulse tracking radar. Additionally, some important electronic counter-countermeasures (ECCM) are incorporated into this signal processing system.

scholarly journals High-speed high-resolution laser diode-based photoacoustic microscopy for in vivo microvasculature imaging

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiufeng Li ◽  
Victor T C Tsang ◽  
Lei Kang ◽  
Yan Zhang ◽  
Terence T W Wong
Keyword(s):  
High Resolution ◽  
High Speed ◽  
High Performance ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
High Signal ◽  
Photoacoustic Microscopy ◽  
Mouse Ear

AbstractLaser diodes (LDs) have been considered as cost-effective and compact excitation sources to overcome the requirement of costly and bulky pulsed laser sources that are commonly used in photoacoustic microscopy (PAM). However, the spatial resolution and/or imaging speed of previously reported LD-based PAM systems have not been optimized simultaneously. In this paper, we developed a high-speed and high-resolution LD-based PAM system using a continuous wave LD, operating at a pulsed mode, with a repetition rate of 30 kHz, as an excitation source. A hybrid scanning mechanism that synchronizes a one-dimensional galvanometer mirror and a two-dimensional motorized stage is applied to achieve a fast imaging capability without signal averaging due to the high signal-to-noise ratio. By optimizing the optical system, a high lateral resolution of 4.8 μm has been achieved. In vivo microvasculature imaging of a mouse ear has been demonstrated to show the high performance of our LD-based PAM system.

scholarly journals Electron microscopy snapshots of single particles from single cells

2018 ◽  
Vol 294 (5) ◽  
pp. 1602-1608 ◽  
Author(s):  
Xiunan Yi ◽  
Eric J. Verbeke ◽  
Yiran Chang ◽  
Daniel J. Dickinson ◽  
David W. Taylor
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Protein Complexes ◽  
Signal To Noise Ratio ◽  
Single Cells ◽  
Particle Analysis ◽  
Biological Macromolecules ◽  
Single Particle Analysis ◽  
Whole Cells ◽  
Potential Applications

Cryo-electron microscopy (cryo-EM) has become an indispensable tool for structural studies of biological macromolecules. Two additional predominant methods are available for studying the architectures of multiprotein complexes: 1) single-particle analysis of purified samples and 2) tomography of whole cells or cell sections. The former can produce high-resolution structures but is limited to highly purified samples, whereas the latter can capture proteins in their native state but has a low signal-to-noise ratio and yields lower-resolution structures. Here, we present a simple, adaptable method combining microfluidic single-cell extraction with single-particle analysis by EM to characterize protein complexes from individual Caenorhabditis elegans embryos. Using this approach, we uncover 3D structures of ribosomes directly from single embryo extracts. Moreover, we investigated structural dynamics during development by counting the number of ribosomes per polysome in early and late embryos. This approach has significant potential applications for counting protein complexes and studying protein architectures from single cells in developmental, evolutionary, and disease contexts.

scholarly journals Rationally Designing Simple Rod-Like Amphiphilic NIR-Emissive AIE Probes for Precise In-Vivo Detection of Aβ Fibrils/Plaques at A Super-Early Stage

2021 ◽  
Author(s):  
Yipu Wang ◽  
Dong Mei ◽  
Xinyi Zhang ◽  
Da-Hui Qu ◽  
Ju Mei ◽  
...  
Keyword(s):  
High Performance ◽  
Ex Vivo ◽  
Early Stage ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
In Vivo Detection ◽  
Different Strains ◽  
Aβ Fibrils

With increase of social aging, Alzheimer's disease (AD) has been one of the serious diseases threatening human health. The occurrence of A<i>β </i>fibrils<i> </i>or plaques is recognized as the hallmark of AD.<i> </i>Currently, optical imaging has stood out to be a promising technique for the imaging of A<i>β</i> fibrils/plaques and the diagnosis of AD. However, restricted by their poor blood-brain barrier (BBB) penetrability, short-wavelength excitation and emission, and aggregation-caused quenching (ACQ) effect, the clinically used gold-standard optical probes such as <a>thioflavin</a> T (ThT) and thioflavin S (ThS), are not effective enough in the early diagnosis of AD <i>in vivo</i>. Herein, we put forward an “all-in-one” design principle and demonstrate its feasibility in developing high-performance fluorescent probes which are specific to A<i>β</i> fibrils/plaques and promising for super-early <i>in</i>-<i>vivo</i> diagnosis of AD. As a proof of concept, a simple rod-like amphiphilic NIR fluorescent AIEgen, i.e., AIE-CNPy-AD, is developed by taking the specificity, BBB penetration ability, deep-tissue penetration capacity, high signal-to-noise ratio (SNR) into consideration. AIE-CNPy-AD is constituted by connecting the electron-donating and accepting moieties through single bonds and tagging with a propanesulfonate tail, giving rise to the NIR fluorescence, aggregation-induced emission (AIE) effect, amphiphilicity, and rod-like structure, which in turn result in high binding-affinity and excellent specificity to A<i>β</i> fibrils/plaques, satisfactory ability to penetrate BBB and deep tissues, ultrahigh SNR and sensitivity, and high-fidelity imaging capability. <i>In-vitro, ex-vivo,</i> and <i>in-vivo</i> <a>identifying of A<i>β</i> fibrils/plaques</a> in different strains of mice indicate that AIE-CNPy-AD holds the universality to the detection of A<i>β</i> fibrils/plaques. It is noteworthy that AIE-CNPy-AD is even able to trace the small and sparsely distributed A<i>β</i> fibrils/plaques in very young AD model mice such as 4-month-old APP/PS1 mice which are reported to be the youngest mice to have A<i>β</i> deposits in brains, suggesting its great potential in diagnosis and intervention of AD at a super-early stage.

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