Virus molecules

The development of high-magnification microscopy made it possible to create images of biological materials at the molecular level. Many of these images show structures that have liquid crystalline aspects. Shown here are aligned mosaic virus molecules and protein molecules in voluntary muscles. In addition, all cell walls are picket fences of rod-shaped molecules in regular yet fluid arra. ... 

The detailed mechanism by means of which a gene or a virus molecule produces replicas of itself is not yet known. In general the use of a gene or a virus as a template would lead to the formation of a molecule not with identical structure but with complementary structure... If the structure that serves as a template (the gene or virus molecule) consists of, say, two parts, which are themselves complementary in structure, then each of these parts can serve as the mold for the production of a replica of the other part, and the complex of two complementary parts thus can serve as the mold for the production of duplicates itself. 

Carbodiimides are widely used to mediate the attachment of biomarkers to polypeptides. Examples include carbodiimides with ferrocenyl substituents. Also, peptides are covalently modified with ferrocenecarboxylic acid using EDCCl and N-hydroxy-succinimide to promote the coupling to surface lysines. They also mediate the attachment of substituents to single walled nanotubes (SWNTs) and multiwalled nanotubes (MWNTs). Also, microdots are attached to virus molecules using a water soluble carbodiimide. The attachment of viral DNA to gold particles is used in the manufacture of a new type of vaccine. 

Another property which virus molecules have, in common with ordinary small molecules, is the ability to form crystals. The molecules of a virus can form crystals because they are all essentially alike in size and shape, and so can pile together in the regular arrangement which constitutes a crystal. 

Two photographs made with the electron microscope are reproduced here, as Figures 3-10 and 3-11. They slio s molecules of viruses which cause disease in tomato plants. Each bushy stunt virus molecule is about 230 A in diameter. It is made of about 750,000 atoms, the necrosis virus molecules are somewhat smaller, about 195 A in diameter. In each photograph the individual molecules can be clearly and in the photographs of necrosis virus protein molecules the... 

The main forces between the tobacco mosaic virus molecules or bentonite particles may be considered repulsive. Since a coacervation... 

The polyoma virus may be a gene that has become abnormal. The molecule of the virus differs from the molecules of the normal gene nucleic acid in that the virus molecules contain rings, whereas the normal molecules are thought to be long chains. 

Each virus molecule consists of two rings intertwined in the complex way shown in the drawing. The molecule may be called a catenane, but it is far more complicated than the simple catenane shown in the preceding drawing. Each ring contains about 150,000 atoms. 

The problem of the way in which an animal is able to manufacture the special molecule of haemoglobin that it needs is part of the general problem of the manufacture of specific biological substances. For example, a virus molecule in the proper environment (that provided by its host) is able to cause the production of replicas of itself, and the phenomena of heredity depend upon the similar autocatalytic action of molecules of genes present in the chromosomes and also in the cytoplasm of cells. 

The question as to why, in the case of bovine albumin films, the amount of adsorbed antibodies increases with the number of underlying monolayers is of importance. First, it seems probable that the antibody molecules are piled up on top of each other in the thick layers of antibodies adsorbed on four double layers of bovine albumin. If this is true, the same process might take place in other cases. It has often been reported that undiluted immune sera gave much thicker layers of specifically adsorbed material than diluted sera. Bateman, Calkins and Chambers (19) found increments in thickness of 200 A and 60 A with undiluted and diluted serum, respectively. These variations have usually been assumed to result from a different orientation of the adsorbed antibody molecule which in the case of the rabbit antibody has approximately the dimensions of 40 X 270 A. Great variations in the thickness of adsorbed layers of antibodies have also been observed by electron microscopy. For instance, Anderson and Stanley (24) reported an adsorbed thickness of 225 A of rabbit antibodies on the surface of tobacco mosaic virus molecules but they also have observed much smaller increments. 

Template-directed ligation of oligonucleotides is accomplished using nucleotide strands with 5 -alkyne and 3 -azide strands to produce DNA strands with an unnatural backbone at the ligation point 2-Propynyl substituted hemicyanine dyes are attached to azide-containing virus molecules... 

The only intermolecular forces which can act over the distances which the X-ray evidence reveals are coulombic. Since the virus molecules are all negatively charged in the systems described, the electrostatic forces between them should be repulsive. It is reasonable that such forces between rod-shaped molecules should lead to a hexagonal array in order to fill the available space as efficiently as possible, and that the spacing should increase progressively upon dilution, as observed for gels in the absence of salt. The existence of mi equilibrium spacing in the presence of salt is more difficult to understand it has been discussed by Levine (1939, 1941) and Hamaker (1946). 

A scientist is conducting some investigations on a strain of the very dangerous Ebola virus, which has caused many deaths in Africa. It is crudely assumed that the individual virus molecule is coiled up to a... 

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