High-Speed Lens-Free Holographic Sensing of Protein Molecules Using Quantitative Agglutination Assays

ACS Sensors ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 1208-1217
Author(s):  
Zhen Xiong ◽  
Colin J. Potter ◽  
Euan McLeod
Keyword(s):  
High Speed ◽  
Protein Molecules

High-Speed Atomic Force Microscopy for Studying the Dynamic Behavior of Protein Molecules at Work

2006 ◽  
Vol 45 (3B) ◽  
pp. 1897-1903 ◽  
Author(s):  
Toshio Ando ◽  
Takayuki Uchihashi ◽  
Noriyuki Kodera ◽  
Atsushi Miyagi ◽  
Ryo Nakakita ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Dynamic Behavior ◽  
High Speed ◽  
Force Microscopy ◽  
Atomic Force ◽  
Protein Molecules

scholarly journals AN IMPROVED AIR-DRIVEN TYPE OF ULTRACENTRIFUGE FOR MOLECULAR SEDIMENTATION

1937 ◽  
Vol 65 (4) ◽  
pp. 565-586 ◽  
Author(s):  
Johannes H. Bauer ◽  
Edward G. Pickels
Keyword(s):  
High Speed ◽  
Optical Systems ◽  
Centrifugal Field ◽  
Braking System ◽  
Axis Of Rotation ◽  
Protein Molecules ◽  
Transparent Cell ◽  
Definition Of ◽  
Operation Characteristics

1. A description is given of the construction details and operation characteristics of an improved type of air-driven ultracentrifuge operating in vacuum and suitable for the determination of sedimentation constants of protein molecules. 2. The rotor of the centrifuge is made of a forged aluminum alloy; it is oval in shape, measures 185 mm. at its greatest diameter, and weighs 3,430 gm. It carries a transparent cell located at a distance of 65 mm. from the axis of rotation and designed to accommodate a fluid column 15 mm. high. 3. The rotor has been run repeatedly over long periods at a speed of 60,000 R.P.M., which corresponds to a centrifugal force of 260,000 times gravity in the center of the cell. At this speed no deformation of the rotor nor leakage of the cell has been observed. 4. The sharp definition of sedimentation photographs taken at high speed serves to indicate the absence of detectable vibrations in the centrifuge. 5. When a vacuum of less than 1 micron of mercury is maintained in the centrifuge chamber, the rise in the rotor temperature amounts to only 1 or 2°C. after several hours' run at high speed. 6. There has been no evidence of convection currents interfering with normal sedimentation of protein molecules in the centrifugal field. 7. A driving air pressure of about 18 pounds per square inch is sufficient to maintain the centrifuge at a steady speed of 60,000 R.P.M. With a driving pressure of 80 pounds per square inch, it can be accelerated to this speed in less than 20 minutes, and also brought to rest in about the same length of time by the application of the braking system. 8. The adaptation of Svedberg's optical systems to this centrifuge for photographically recording the movement of sedimentation boundaries is described.

scholarly journals High-speed Atomic Force Microscopy for Capturing Dynamic Behavior of Protein Molecules at Work

2005 ◽  
Vol 3 ◽  
pp. 384-392 ◽  
Author(s):  
Toshio Ando ◽  
Noriyuki Kodera ◽  
Takayuki Uchihashi ◽  
Atsushi Miyagi ◽  
Ryo Nakakita ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Dynamic Behavior ◽  
High Speed ◽  
Force Microscopy ◽  
Atomic Force ◽  
Protein Molecules

Occurrence, Molecular Structure, and Induced Formation of the ‘Stromacentre’ in Plastids

1968 ◽  
Vol 3 (3) ◽  
pp. 445-456
Author(s):  
B. E. S. GUNNING ◽  
M. W. STEER ◽  
M. P. COCHRANE
Keyword(s):  
High Speed ◽  
Osmium Tetroxide ◽  
Membrane System ◽  
Close Packing ◽  
Hexagonal Close Packing ◽  
Side View ◽  
Fraction I Protein ◽  
Protein Molecules ◽  
Free Particles ◽  
Fraction I

The ‘stromacentre’ is a fibrillar spherulite found in plastids of aldehyde osmium-tetroxide fixed leaves of species in the genus Avena. Fibrils, each up to 0.2 µ x 80-90 Å, are associated in bundles, sometimes in hexagonal close packing, and the bundles in turn are aggregated in the spherulite. Individual bundles, or structures resembling them, occur in the plastid stroma in some other plants. In Avena, the stromacentre develops along with the internal membrane system of the plastids. Its staining reactions suggest absence of nucleic acid, and that it is proteinaceous. It is probably present in all mature Avena plastids. Stromacentre fibrils have been negatively stained. They consist of linearly aggregated particles. In side view these measure about 85-90 Å square, though the outline of the particles varies according to the orientation of the fibril. Particle outlines and staining patterns within particles are illustrated in photographically reinforced images. Micrographs interpreted as illustrating disaggregation into free particles are presented. These free particles are indistinguishable from numerous others in the preparations, and these in turn are thought to be Fraction I protein molecules. A process somewhat similar to stromacentre formation occurs in etioplasts and chloroplasts in Phaseolus leaves that have been dehydrated by plasmolysis, by wilting, or by high-speed centrifugation. These aggregates are not quite the same as the Avena stromacentre, but negative staining shows that they too are composed of units that are about the same size as Fraction I protein molecules. The hypothesis that the stromacentre fibrils consist of linearly aggregated Fraction I protein molecules is discussed.

scholarly journals 2P289 Preparation of substrata for high-speed AFM imaging of protein molecules at work

2004 ◽  
Vol 44 (supplement) ◽  
pp. S182
Author(s):  
D. Maeda ◽  
A. Miyagi ◽  
N. Kodera ◽  
T. Ando
Keyword(s):  
High Speed ◽  
Afm Imaging ◽  
Protein Molecules

scholarly journals Molecular weights and metabolism of rat brain proteins

1970 ◽  
Vol 116 (4) ◽  
pp. 745-753 ◽  
Author(s):  
R. Vrba ◽  
Wendy Cannon
Keyword(s):  
Sodium Chloride ◽  
High Speed ◽  
Gel Filtration ◽  
Specific Radioactivity ◽  
Sodium Deoxycholate ◽  
Dynamic State ◽  
Brain Proteins ◽  
Molecular Weights ◽  
Protein Molecules ◽  
The Brain

1. Rats were injected with [U-14C]glucose and after various intervals extracts of whole brain proteins (and in some cases proteins from liver, blood and heart) were prepared by high-speed centrifugation of homogenates in 0.9% sodium chloride or 0.5% sodium deoxycholate. 2. The extracts were subjected to gel filtration on columns of Sephadex G-200 equilibrated with 0.9% sodium chloride or 0.5% sodium deoxycholate. 3. Extracts prepared with both solvents displayed on gel filtration a continuous range of proteins of approximate molecular weights ranging from less than 2×104 to more than 8×105. 4. The relative amount of the large proteins (mol.wt.>8×105) was conspicuously higher in brain and liver than in blood. 5. At 15min after the injection of [U-14C]glucose the smaller protein molecules (mol.wt.<2×104) were significantly radioactive, whereas no 14C could be detected in the larger (mol.wt.>2×104) protein molecules. The labelling of all protein samples was similar within 4h after injection of [U-14C]glucose. Fractionation of brain proteins into distinctly different groups by the methods used in the present work yielded protein samples with a specific radioactivity comparable with that of total brain protein. 6. No evidence could be obtained by the methods used in the present and previous work to indicate the presence of a significant amount of ‘metabolically inert protein’ in the brain. 7. It is concluded that: (a) most or all of the brain proteins are in a dynamic state of equilibrium between continuous catabolism and anabolism; (b) the continuous conversion of glucose into protein is an important part of the maintenance of this equilibrium and of the homoeostasis of brain proteins in vivo.

scholarly journals Protein identification with a nanopore and a binary alphabet

2017 ◽  
Author(s):  
G. Sampath
Keyword(s):  
Single Molecule ◽  
High Speed ◽  
Protein Identification ◽  
Binary Sequences ◽  
False Detection Rate ◽  
False Detection ◽  
Post Translational Modifications ◽  
Identification Rate ◽  
Binary Alphabet ◽  
Protein Molecules

AbstractProtein sequences are recoded with a binary alphabet obtained by dividing the 20 amino acids into two subsets based on volume. A protein is identified from subsequences by database search. Computations on the Helicobacter pylori proteome show that over 93% of binary subsequences of length 20 are correct at a confidence level exceeding 90%. Over 98% of the proteins can be identified, most have multiple identifiers so the false detection rate is low. Binary sequences of unbroken protein molecules can be obtained with a nanopore from current blockade levels proportional to residue volume; only two levels, rather than 20, need be measured to determine a residue’s subset. This procedure can be translated into practice with a sub-nanopore that can measure residue volumes with ~0.07 nm3 resolution as shown in a recent publication. The high detector bandwidth required by the high speed of a translocating molecule can be reduced more than tenfold with an averaging technique, the resulting decrease in the identification rate is only 10%. Averaging also mitigates the homopolymer problem due to identical successive blockade levels. The proposed method is a proteolysis-free single-molecule method that can identify arbitrary proteins in a proteome rather than specific ones. This approach to protein identification also works if residue mass is used instead of mass; again over 98% of the proteins are identified by binary subsequences of length 20. The possibility of using this in mass spectrometry studies of proteins, in particular those with post-translational modifications, is under investigation.

scholarly journals Direct Observation of Hop Diffusion of Lipid and Protein Molecules in the Plasma Membrane by High-Speed Single Fluorescent-Molecule Imaging

2010 ◽  
Vol 98 (3) ◽  
pp. 305a-306a
Author(s):  
Takahiro K. Fujiwara ◽  
Shinji Takeuchi ◽  
Yosuke Nagai ◽  
Kazuhide Hanaka ◽  
Kokoro Iwasawa ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Direct Observation ◽  
High Speed ◽  
Fluorescent Molecule ◽  
Protein Molecules
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