Flash Oxidation (FOX) System: A Novel Laser-Free Fast Photochemical Oxidation Protein Footprinting Platform

2021 ◽  
Author(s):  
Joshua S. Sharp ◽  
Emily E. Chea ◽  
Sandeep K. Misra ◽  
Ron Orlando ◽  
Marla Popov ◽  
...  
Keyword(s):  
Photochemical Oxidation ◽  
Protein Footprinting ◽  
System A

Protein Footprinting with Radical Probe Mass Spectrometry- Two Decades of Achievement

2019 ◽  
Vol 26 (1) ◽  
pp. 4-15 ◽  
Author(s):  
Simin D. Maleknia ◽  
Kevin M. Downard
Keyword(s):  
Mass Spectrometry ◽  
Hydroxyl Radicals ◽  
Protein Structures ◽  
Protein Docking ◽  
Photochemical Oxidation ◽  
Annual Conference ◽  
Protein Footprinting ◽  
X Ray ◽  
American Society ◽  
The Impact

Background: Radical Probe Mass Spectrometry (RP-MS) describes a pioneering methodology in structural biology that enables the study of protein structures, their interactions, and dynamics on fast timescales (down to sub-milliseconds). Hydroxyl radicals (•OH) generated directly from water within aqueous solutions induce the oxidation of reactive, solvent accessible amino acid side chains that are then analyzed by mass spectrometry. Introduced in 1998 at the American Society for Mass Spectrometry annual conference, RP-MS was first published on in 1999. Objective: This review article describes developments and applications of the RP-MS methodology over the past two decades. Methods: The RP-MS method has been variously referred to as synchrotron X-ray radiolysis footprinting, Hydroxyl Radical Protein Footprinting (HRPF), X-ray Footprinting with Mass Spectrometry (XF-MS), Fast Photochemical Oxidation of Proteins (FPOP), oxidative labelling, covalent oxidative labelling, and even the Stability of Proteins from Rates of Oxidation (SPROX). Results: The article describes the utility of hydroxyl radicals as a protein structural probe, the advantages of RP-MS in comparison to other MS-based approaches, its proof of concept using ion mobility mass spectrometry, its application to protein structure, folding, complex and aggregation studies, its extension to study the onset of protein damage, its implementation using a high throughput sample loading approach, and the development of protein docking algorithms to aid with data analysis and visualization. Conclusion: RP-MS represents a powerful new structural approach that can aid in our understanding of the structure and functions of proteins, and the impact of sustained oxidation on proteins in disease pathogenesis.

scholarly journals Fast Photochemical Oxidation of Proteins Coupled with Mass Spectrometry

2019 ◽  
Vol 26 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Liuqing Shi ◽  
Michael L. Gross
Keyword(s):  
Mass Spectrometry ◽  
Hydroxyl Radical ◽  
Protein Modification ◽  
Solvent Accessibility ◽  
Conformational Dynamics ◽  
Photochemical Oxidation ◽  
Structural Proteomics ◽  
Sequence Coverage ◽  
Protein Footprinting

Background: Determination of the composition and some structural features of macromolecules can be achieved by using structural proteomics approaches coupled with mass spectrometry (MS). One approach is hydroxyl radical protein footprinting whereby amino-acid side chains are modified with reactive reagents to modify irreversibly a protein side chain. The outcomes, when deciphered with mass-spectrometry-based proteomics, can increase our knowledge of structure, assembly, and conformational dynamics of macromolecules in solution. Generating the hydroxyl radicals by laser irradiation, Hambly and Gross developed the approach of Fast Photochemical Oxidation of Proteins (FPOP), which labels proteins on the sub millisecond time scale and provides, with MS analysis, deeper understanding of protein structure and protein-ligand and protein- protein interactions. This review highlights the fundamentals of FPOP and provides descriptions of hydroxyl-radical and other radical and carbene generation, of the hydroxyl labeling of proteins, and of determination of protein modification sites. We also summarize some recent applications of FPOP coupled with MS in protein footprinting. Conclusion: We survey results that show the capability of FPOP for qualitatively measuring protein solvent accessibility on the residue level. To make these approaches more valuable, we describe recent method developments that increase FPOP’s quantitative capacity and increase the spatial protein sequence coverage. To improve FPOP further, several new labeling reagents including carbenes and other radicals have been developed. These growing improvements will allow oxidative- footprinting methods coupled with MS to play an increasingly significant role in determining the structure and dynamics of macromolecules and their assemblies.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

High-resolution electron microscopy of Cu2O surfaces

1986 ◽  
Vol 44 ◽  
pp. 396-397
Author(s):  
V. Castano ◽  
W. Krakow
Keyword(s):  
High Resolution ◽  
Natural Extension ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Initial Oxidation ◽  
System A ◽  
Resolution Electron ◽  
Surface Reconstructions ◽  
Atomic Surface ◽  
Au Thin Films

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.

Twin boundary structure of a Y-Ba-Cu-O superconductor

1989 ◽  
Vol 47 ◽  
pp. 168-169
Author(s):  
Yimei Zhu ◽  
Masaki Suenaga ◽  
R. L. Sabatini ◽  
Youwen Xu
Keyword(s):  
Twin Boundary ◽  
Fine Particles ◽  
Imaging Techniques ◽  
Fine Powder ◽  
Orthorhombic Phase ◽  
Boundary Structure ◽  
Crystallographic Axis ◽  
System A ◽  
High Resolution Structure ◽  
Electron Microscopes

The (110) twin structure of YBa2Cu3O7 superconductor oxide, which is formed to reduce the strain energy of the tetragonal to orthorhombic phase transformation by alternating the a-b crystallographic axis across the boundary, was extensively investigated. Up to now the structure of the twin boundary still remained unclear. In order to gain insight into the nature of the twin boundary in Y-Ba-Cu-O system, a study using electron diffraction techniques including optical and computed diffractograms, as well as high resolution structure imaging techniques with corresponding computer simulation and processing was initiated.Bulk samples of Y-Ba-Cu-O oxide were prepared as described elsewhere. TEM specimens were produced by crushing bulk samples into a fine powder, dispersing the powder in acetone, and suspending the fine particles on a holey carbon grid. The electron microscopy during this study was performed on both a JEOL 2000EX and 2000FX electron microscopes operated at 200 kV.

Speech Therapy Services in a Large School System: A Six-Year Overview

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches
Keyword(s):  
School System ◽  
Speech Therapy ◽  
Factors Affecting ◽  
Case Load ◽  
Number Of Children ◽  
School Population ◽  
System A ◽  
Therapy Services ◽  
And Shifts ◽  
Selection Factors

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.

1004: In-Vivo Transfection of the Rat Corpus Cavernosum Using a Non-Viral, Linear Polyethylenimine Gene Delivery System: A Novel Application

2006 ◽  
Vol 175 (4S) ◽  
pp. 323-324 ◽  
Author(s):  
Joseph Dall'era ◽  
Sweaty Koul ◽  
Jesse Mills ◽  
Jeremy Myers ◽  
Randall B. Meacham ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Delivery System ◽  
Corpus Cavernosum ◽  
Gene Delivery System ◽  
System A ◽  
In Vivo Transfection ◽  
Linear Polyethylenimine
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