(1) The crystallographic parameters of four different unit cells, all of which are based on hexagonal packing arrangements, indicate that the fundamental unit of the complex is composed of six gene 5 protein dimers.
(2) The molecular structure of the hexagonal crystal form of porcine pepsin (EC 3.4.23.1), an aspartic proteinase from the gastric mucosa, has been determined by molecular replacement using the fungal enzyme, penicillopepsin (EC 3.4.23.6), as the search model.
(3) The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons.
(4) Crystal structure analysis and refinement at 2.0 A resolution of a rhombohedral crystal form of human annexin V at high calcium concentration revealed a domain motion compared to the previously analysed hexagonal crystal form.
(5) Abnormalities included absence of a hexagonal pattern, incomplete portal tracts with dilated veins only, lack of bile ducts and canaliculi, and apparent failure of bile formation and glycogen deposition.
(6) Using a hexagonal electrode array and switching times of 75 min at 45 V for 14 days, nine bands could be resolved.
(7) The PENN-PET scanner consists of six hexagonally arranged position-sensitive Nal(TI) detectors.
(8) This result was quite the same as that of the hexagonal plate crystals.
(9) When negatively stained with uranyl acetate, LPSI was ribbon-like but LPSII exhibited hexagonal lattice structures.
(10) Endothelial specular photography during an attack reveals dramatic changes: large black nonreflecting areas between quite normal-looking hexagonal cells.
(11) It is suggested that distortion in the hexagonal lattice below the pretransition temperature previously reported by X-ray diffraction techniques may be responsible for interchain interactions which give rise to a Raman band observed only in the triclinic lattice of even-numbered n-alkanes.
(12) 31P-NMR and X-ray diffraction techniques are used to study the comparative ability of myelin basic protein (MBP) vs. other basic proteins to convert hexagonal (HII) phases to stable lamellar (L alpha) structures.
(13) The influence of the intercalation of ethidium bromide (EB) on the characteristics of the DNA cholesteric and hexagonal mesophases is studied by optical microscopy, circular dichroism, and X-ray diffraction.
(14) Wide angle X-ray diffraction results indicate no major effect of the protein on the 4.1 A spacing, characteristic of hexagonal packing of the hydrocarbon chains.
(15) After in vitro perfusion of cytochalasin D to the corneal endothelium, the F-actin became randomly distributed throughout the cytoplasm, the hexagonal shape of the endothelial cell was disrupted, and endothelial permeability to carboxyfluorescein increased.
(16) The thermophilic eubacterium Clostridium thermohydrosulfuricum L77-66 is covered by a crystalline surface layer composed of identical glycoprotein subunits which are arranged in a hexagonal lattice with centre-to-centre spacings of approx.
(17) Pyramidal, cubical or hexagonal magnetic grains could be seen in different species of bacteria.
(18) The six subunits form a hexagon which is skewed with respect to the main rows of hexagons in such a way that the subunits lie on rows which make an angle of approximately 37 degrees with the main rows.
(19) In the invaginating synapses of cone pedicles, the plasma membrane of the photoreceptor ending contains an aggregate of A-face particles, a hexagonal array of synaptic vesicle sites, and rows of coated vesicle sites, which are deployed in sequence from apex to base of the synaptic ridge.
(20) The design and construction of a transistor-driven hexagonal contour-clamped homogeneous electric field (CHEF) apparatus is discussed in detail.
Icosahedron
Definition:
(n.) A solid bounded by twenty sides or faces.
Example Sentences:
(1) The dimensions and shape of the head are compatible with those of a regular icosahedron.
(2) These data showed the feasibility of the insertion of foreign sequences in a specific antigenically active locus of the poliovirus icosahedron, and suggest some limitations with respect to the sequences to be 'transplanted'.
(3) Older cultures revealed clusters of icosahedrons some of which degenerated spontaneously; others were surrounded by proteinic structure having a fringed aspect.
(4) Icosahedron-shaped particles with an average diameter of 33 nm were liberated by treatment of the fraction with the detergent Tween 80.
(5) Electron microscopic studies demonstrated that purified virions have a typical adenovirus morphologic characteristic, with 50-nm-long fiber projections at each vertex of an 80-nm-diameter icosahedron.
(6) The internal space of an icosahedron can optimally be filled by 12 geometrical figures each of which is a combination of a cone and more than half of a sphere.
(7) Phage Bam35 is an icosahedron of about 63 nm in diameter.
(8) These data predict that the nucleocapsid contains 240 copies of protein and is a T = 4 icosahedron.
(9) The virus is composed of 32 hollow morphological units representing a regular T = 3 icosahedron.
(10) Treatment of single-capsid rotavirus particles with 30% formamide or 5 M-urea resulted in their degradation, giving rise to very similar products, corresponding to isolated vertices, edges and faces of the virus icosahedron.
(11) This virus was an icosahedron of 145 nm and most likely to be placed in the family Iridoviridae.
(12) Approximately 15 molecules of IX were found per group of nine hexons and from considerations of symmetry it seemed possible that IX was located at the 'corner to edge' contacts between hexons in the icosahedron.
(13) This paper describes a method for the rapid searching of rotational three-dimensional space, relying on the symmetries of the regular icosahedron and dodecahedron.
(14) We have found that E1-E2 heterodimers, which form the virus protomeric units, exist in two conformationally distinct forms, reflecting their nonequivalent positions in the icosahedron.
(15) The model capsid is defined by the underlying icosahedron, of edge 445 A, upon which hexons are arranged.
(16) The virus was sensitive to the action of lipid solvents and trypsin and was rapidly inactivated at pH 3.0 and at temperatures of 50 and 56 C. The virion, an icosahedron consisting of a nucleoid surrounded by a double membrane, measured approximately 135 nm in diameter.
(17) Protein-protein associations have been identified which participate in the formation of the icosahedron and these associations are stabilized by intramolecular disulfide bridges (Anthony, R. P., and Brown, D. T., 1990, J. Virol.
(18) The measured relative dimensions of the different heads fit best the relative dimensions predicted by a quasi-icosahedral model in which the smallest T4 head corresponds to an icosahedron with a triangulation number T = 21.
(19) These phages contain 2-DNA, their head is a regular icosahedron, the tail consisting of a helix of protein subunits is attached to the head by a narrowed segment and is fixed in it by means of a disc-like structure.
(20) This can be explained in terms of icosahedron and cuboctahedron type clusters deposited on the surface of the carbon layer.