Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

QUATERNARY STRUCTURE OF PEA PHYTOCHROME I DIMER STUDIED WITH SMALL-ANGLE X-RAY SCATTERING and ROTARY-SHADOWING ELECTRON MICROSCOPY

1990 ◽  
Vol 52 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Masayoshi Nakasako ◽  
Masamitsu Wada ◽  
Satoru Tokutomi ◽  
Kotaro T. Yamamoto ◽  
Jun Sakai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Angle ◽  
Quaternary Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Rotary Shadowing ◽  
Ray Scattering

The resolution of individual protein subunits in ferritin

1978 ◽  
Vol 36 (2) ◽  
pp. 182-183
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
Storage Protein ◽  
Quaternary Structure ◽  
Negative Staining ◽  
Variable Amount ◽  
X Ray Diffraction ◽  
Iron Storage ◽  
Protein Subunits ◽  
X Ray ◽  
Iron Storage Protein

The technique of negative staining has been of very great value for directly determining the quaternary structure of individual multimeric proteins and viruses. In this regard, the iron-storage protein,, ferritin, is a notable exception for not having had its subunits unambiguously resolved by negative staining. Each ferritin molecule (d= 120Å) has an outer shell of 24 protein subunits (MW= 18,500) surrounding a variable amount of mineralized iron; published x-ray diffraction studies have not yet defined individual monomers in the polymeric shell. Claims that single subunits have been visualized in ferritin by electron microscopy (e.g.,6) all appear to be of highly doubtful validity since the phase granularity of the dried stain and supporting film has the same dimension as the presumed subunits; apparent subunits are readily visualized in defocused images, but are no longer discernable when brought closer to exact focus.

Dissociation of Limulus polyphemus (horseshoe crab) hemocyanin. II. Stopped-flow X-ray scattering study

1992 ◽  
Vol 43 (1) ◽  
pp. 73-80
Author(s):  
Kazumoto Kimura ◽  
Yoshihiko Igarashi ◽  
Hirotsugu Tsuruta ◽  
Hiroshi Kihara ◽  
Akihiko Kajita
Keyword(s):  
Horseshoe Crab ◽  
Limulus Polyphemus ◽  
Stopped Flow ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

scholarly journals SPICA: stereographic projection for interactive crystallographic analysis

2016 ◽  
Vol 49 (5) ◽  
pp. 1818-1826 ◽  
Author(s):  
X.-Z. Li
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stereographic Projection ◽  
Crystallographic Analysis ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
X Ray ◽  
Research Fields ◽  
Transmission Electron

In numerous research fields, especially the applications of electron and X-ray diffraction, stereographic projection represents a powerful tool for researchers. SPICA is a new computer program for stereographic projection in interactive crystallographic analysis, which inherits features from the previous JECP/SP and includes more functions for extensive crystallographic analysis. SPICA provides fully interactive options for users to plot stereograms of crystal directions and crystal planes, traces, and Kikuchi maps for an arbitrary crystal structure; it can be used to explore the orientation relationships between two crystalline phases with a composite stereogram; it is also used to predict the tilt angles of transmission electron microscopy double-tilt and rotation holders in electron diffraction experiments. In addition, various modules are provided for essential crystallographic calculations.

What can Crystallographic Analysis tell us About Fibrinogen?

1979 ◽  
Author(s):  
Carolyn Cohen ◽  
John W. Weisel
Keyword(s):  
Electron Microscopy ◽  
Protein Molecule ◽  
Crystallographic Analysis ◽  
X Ray Diffraction ◽  
Technical Problems ◽  
Crystal Forms ◽  
X Ray ◽  
X Ray Crystallography ◽  
Large Size ◽  
Hydrated Protein

A major project in our laboratory has been the determination of the molecular structure of fibrinogen and its Interactions to form fibrin. We have approached this problem by attempting to obtain ordered forms of fibrinogen and, In fact, to crystallize the molecule. X-ray crystallography is the only objective method that can yield the detailed structure of the native hydrated protein molecule. In order to obtain crystals of fibrinogen, we found that limited proteolytic digestion is required. We have now produced three macroscopic crystal forms and a variety of microcrystals using several different enzymes and fibrinogens from different species. These modified molecules are largely intact and retain their biological function to form clots with thrombin similar in appearance to native fibrin by electron microscopy. The degree of order in all these aggregates is, moreover, far superior to that of fibrin. Some of the microcrystalline forms have been shown to be closely related to fibrin. Since the fibrinogen molecule is several times larger than any protein yet solved by X-ray methods, the technical problems in the crystallographic analysis are formidable. Because of the large size of the molecule, however, electron microscopy provides Information essential for the solution. We have completed a preliminary X-ray characterization of the ctystals and, using coordinated X-ray diffraction and electron microscopy, deduced plausible packing models. The results from this first stage in the X-ray analysis of fibrinogen give insight also into the packing of the molecules to form fibrin. Supported by USPHS grant #AM17346.

scholarly journals Domain growth of Dy2O3 buffer layers on SrTiO3

1993 ◽  
Vol 8 (6) ◽  
pp. 1373-1378 ◽  
Author(s):  
A. Catana ◽  
J-P. Locquet
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Substrate Surface ◽  
Crystallographic Analysis ◽  
Buffer Layers ◽  
Domain Growth ◽  
Structural Perfection ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

Dy2O3 layers have been grown on SrTiO3 by molecular beam epitaxy. X-ray and electron diffraction patterns clearly show that Dy2O3 grows epitaxially on SrTiO3 with {100} planes parallel to the substrate surface. Transmission electron microscopy reveals that the Dy2O3 film breaks up into small domains (10–40 nm). This leads to the formation of terraces which limits the structural perfection of thin overgrown DyBa2Cu3O7 by introducing steps and small misorientations (within 3°). The resulting surface corrugation does not preclude the growth of epitaxial c-axis DyBa2Cu3O7 films with a Tc0 of 86 K. Crystallographic analysis and image calculations show that the domain growth of Dy2O3 is associated with the formation of 90° rotation twins.

High Resolution X-Ray Contact Microscopy of Hydrated Muscle Filaments

1981 ◽  
Vol 39 ◽  
pp. 512-513
Author(s):  
B.J. Panessa ◽  
M.M. Dewey ◽  
P. Brink ◽  
B. Gaylinn ◽  
R.A. McCorkle ◽  
...  
Keyword(s):  
Horseshoe Crab ◽  
Mercenaria Mercenaria ◽  
Adductor Muscle ◽  
Limulus Polyphemus ◽  
Myosin Filament ◽  
Standard Methods ◽  
X Ray ◽  
Cellular Debris ◽  
Myosin Filaments ◽  
Better Than

Soft x-ray contact microscopy is a relatively new method for imaging biological materials at resolutions of 5-30 nm. By using a wet cell, and flash x-ray source to reduce the exposure time, we have been able to obtain high contrast images of hydrated biological specimens at better than 30 nm resolution. This paper describes the technique and results of using this type of “wet” microscopy for the examination of hydrated invertebrate isolated myosin filament, and paramyosin paracrystal,preparations.Paramyosin paracrystals and myosin filaments were isolated from telson muscle of the horseshoe crab, Limulus polyphemus L. The muscle was homogenized and the cellular debris and filaments segregated by differential centrifugation. Isolated filaments were resuspended in buffer (Tris, pH 7.4-7.5), and dialyzed overnight against buffer containing EDTA at 4°C. Tissue taken from the white adductor muscle of the clam, Mercenaria mercenaria, was similarly homogenized and isolated by standard methods.

scholarly journals Dynamics of Quaternary Structure Transitions in R-State Carbonmonoxyhemoglobin Unveiled in Time-Resolved X-ray Scattering Patterns Following a Temperature Jump

2018 ◽  
Vol 122 (49) ◽  
pp. 11488-11496 ◽  
Author(s):  
Hyun Sun Cho ◽  
Friedrich Schotte ◽  
Valentyn Stadnytskyi ◽  
Anthony DiChiara ◽  
Robert Henning ◽  
...  
Keyword(s):  
Temperature Jump ◽  
Quaternary Structure ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering
Sign in / Sign up

Export Citation Format

Share Document