| the infection of cucumber mesophyll protoplasts with tobacco mosaic virus. | protoplasts from the first leaf mesophyll of cucumber plants were isolated by an 18 hours combined petinase/cellulase treatment. conditions favouring the infection of these protoplasts with tobacco mosaic virus (tmv), and the accumulation of infective virus up to 96 hours after inoculation have been studied. infection of approximately 5--10 per cent of the protoplats, revealed by indirect fluorescent antibody staining, was achieved by pre-treatment of the cells in 0.01 m citrate-buffered mannito ... | 1976 | 11764 |
| the rye embryo system as an alternative to the wheat system for protein synthesis in vitro. | isolated rye embryos are a readily available source for the preparation of very active, cell-free, protein-synthesizing systems. incorporation levels up to 2000 pmol leucine per 50 mul assay are routinely obtained at saturating tmv (tobacco mosaic virus) rna concentrations; at limiting messenger rna concentrations the incorporation exceeds 1000 leucine molecules per tmv rna molecule. the characteristics of this cell-free system for the translation of tmv rna are identical with those of a similar ... | 1976 | 10004 |
| self-assembly of biological macromolecules. | the genetic apparatus of the cell is responsible for the accurate biosynthesis of the primary structure of macromolecules which then spontaneously fold up and, in certain circumstances, aggregate to yield the complex tertiary and quaternary structures of the biologically active molecules. structures capable of self-assembly in this range from simple monomers through oligomers to complex multimeric structures that may contain more than one type of polypeptide chain and components other than prote ... | 1975 | 1808 |
| circular-dichroism and absorption spectroscopic studies on specific aromatic residues involved in the different modes of aggregation of tobacco-mosaic-virus protein. | conformational changes accompanying the different modes of aggregation of tobacco mosaic virus protein (tmv-protein) were investigated using circular dichroism (cd) and absorption difference spectra in the range of aromatic absorption. comparing wild-type protein and mutant ni 2068 (tyr-139 leads to cys-139) a tentative localization of aromatic amino acids in the three-dimensional structure is rendered possible. in all modes of aggregation the cd spectra are determined by intrasubunit interactio ... | 1976 | 2466 |
| polyamino acid induced aphid transmission of plant viruses. | aphids transmitted poly-l-ornithine (plo)-treated tobacco mosaic virus (tmv) when given acquistion and inoculation access periods as brief as 30 s and 2 min, respectively; the ability to transmit was lost within 90 min. aphids without claws were able to transmit the virus. transmission thus seems similar to that of nonpersistent viruses. the ratio of virus to polyamino acid, as well as the kcl concentration, markedly affected transmission. transmission was best from mixtures which contained 250 ... | 1975 | 1467 |
| effect of amino acid replacement on the stability of the tobacco mosaic virus protein structure. | a comparative polarographic study on the alkaline degradation of tobacco mosaic virus (tmv) strain vulgare and its mutant tmv 483, having histidine instead of glutamine at position 9 in the polypeptide chain, was performed. in the course of alkaline degradation and subsequent incubation in the supporting electrolyte at 0 degrees c tmv 483, unlike tmv vulgare, showed a polarographic effect indicating the unfolding of the tmv polypeptide. it was concluded that the replacement of glutamine-9 by his ... | 1977 | 22230 |
| hydrogen ion uptake upon tobacco mosaic virus protein polymerization. | | 1977 | 22763 |
| saturation transfer electron paramagnetic resonance spectroscopy of spin labeled tobacco mosaic virus protein. | | 1977 | 23118 |
| tobacco mosaic virus protein: sedimentation equilibrium studies of the initial stages of polymerization. | the lowest stages of polymerization of tobacco mosaic virus protein were studied by means of high-speed sedimentation equilibrium experiments. several distinct modes of polymerization were found. at ph 7.1 the expected monomer-trimer-higher polymer equilibrium was observed--very little dimer was detected at this ph. at ph 7.5, however, a strong dimerization was observed--neither monomer nor trimer was detected at this ph. an octamer appeared to be the only species present other than the dimer. w ... | 1977 | 22344 |
| hydrogen-ion binding by tobacco-mosaic-virus protein polymers. | hydrogen ion titration curves of tobacco mosaic virus protein have been measured in various conditions of protein concentration, temperature, ionic strength, and rate of ph change. the polymers present at each stage are deduced from turbidity and sedimentation data, plus published information. a simple semi-quantitative analysis of the curves is given, and the pk values of the two abnormal carboxylates in single helix are estimated as 6.4 and about 7.0. disks, and some faster-forming unknown pol ... | 1977 | 21086 |
| comparison of interferon-inducing activities and antiviral effects of tobacco mosaic virus, tilorone and sodium nucleinate. | endogenous interferon was produced in animals in response to the administration of tobacco mosaic virus (tmv), tilorone and sodium nucleinate. the relationship between interferon production and the kind of inducer and the route of its administration was studied. tmv was completely innocuous for macaca rhesus monkeys and mice and caused no untoward effects in humans upon peroral administration. tmv, tilorone and sodium nucleinate given per os exerted a marked protective effect in mice against tic ... | 1977 | 20769 |
| metastable aggregates in the polymerisation of tobacco-mosaic-virus protein. | | 1977 | 21087 |
| cation binding by tobacco mosaic virus. | | 1977 | 16379 |
| interaction of tobacco mosaic virus and tobacco mosaic virus protein with bovine serum albumin. | | 1977 | 13727 |
| stimulation of in vitro translation of messenger rna by actinomycin d and cordycepin. | actinomycin d and cordycepin were tested for their effect on translation in the wheat germ embryo extract and reticulocyte lysate assays for in vitro protein synthesis. both drugs were found to stimulate the incorporation of 35s-labeled methionine into protein up to threefold as compared to control assays. this was true for synthesis directed by murine myeloma polyadenylate-containing rna, tobacco mosaic virus rna, and endogenous reticulocyte messenger rna. | 1977 | 17919 |
| kinetics of the polymerization reaction of tobacco mosaic virus protein: transient-saturation type polymerization reaction. | the kinetics of the endothermic polymerization reaction of tobacco mosaic virus protein in the mild acid region was studied by means of temperature-jump (rising time of 6 sec)-turbidimetry, electron microscopy, and computer simulation. the time course profile of the turbidity increase changed from a normal one to an anomalous one as the size of the temperature-jump was made greater. the anomalous type polymerization profile, which we named the "transient-saturation" type, could be characterized ... | 1977 | 15670 |
| the use of tris-hcl buffer for inoculation of tomato protoplasts with tobacco mosaic virus. | when tris-hcl was used as the buffer for inoculation of tomato protoplasts with tobacco mosaic virus, a greater proportion became infected than when phosphate was used. using 0-05 m-tris-hcl buffer, ph 8-0, in the presence of poly-l-ornithine or poly-d-lysine, 50 to 80 % infection was obtained. | 1976 | 14223 |
| immunochemical studies of tobacco mosaic virus--iii. demonstration of five antigenic regions in the protein sub-unit. | | 1979 | 90642 |
| specific encapsidation of fragments of tmv rna. | the in vitro reconstitution of tobacco mosaic virus (tmv) is initiated by the binding of a disk of tmv protein to the 'disk recognition site', a region of the rna chain at or near the 5'-terminus for which the disk has special affinity. in order to gain insight into the recognition process, we have studied the ability of disks to encapsidate short rna fragments produced by partial pancreatic or t1 rnase digestion of tmv rna. the disk is capable of dicriminating among such fragments, encapsidatin ... | 1976 | 13430 |
| tobacco rattle virus rna-protein interactions. | for the purpose of attempting to generalize the rules concerning morphogenesis of helical viruses, the in vitro reconstitution of the cam strain of trv was studied. the conditions for reconstitution and the importance of the aggregation state of the protein for initiation and elongation are compared with those of tmv. the initiation step consisting of the binding of rna with the 36s disk of protein was easily accomplished. the polarity and the specificity of encapsidation of trv rna by homologou ... | 1976 | 13428 |
| assembly of tobacco mosaic virus. | the assembly of tobacco mosaic virus requires the presence of a particular protein aggregate, the disk. during the nucleation, a specific region of the rna interacts with a single disk, to bring about a necessarily cooperative transition from the paired two-layer structure to a short segment of nucleo-protein helix. there is a high selectivity for this region of the tmv rna, because of the many nucleotides bound at once, and other nucleotide sequences appear only to bind by a different mechanism ... | 1976 | 13427 |
| the region of tobacco mosaic virus rna involved in the nucleation of assembly. | the interaction of tmv rna with the disk aggregate of tmv protein at the initiation of assembly has been studied by using the techniques of rna sequencing. the 5' end group has been identified, and shown not to be protected in the early stages of assembly from accessibility to nuclease digestion. a population of rna fragments of average length 250 nucleotides, originating from a unique region of tmv rna, is encapsidated by limited assembly, and sufficient sequence information is available to ide ... | 1976 | 13431 |
| uptake of labelled tobacco mosaic virus by tobacco protoplasts in the presence of metabolic inhibitors and at low temperature. | in the presence of inhibitors of protein synthesis and energy metabolism, tobacco protoplasts were shown to retain 14c-labelled tobacco mosaic virus (14c-tmv) with the same intensity as in control. at 2 degrees c, the protoplasts retained 14c-tmv at approximately the same rate as at 25 degrees c. in protoplasts inocculated at different temperatures, approximately equal amounts of infectious virus were produced, this being possibly indicative of a non-physiological nature of the first stages of v ... | 1976 | 11673 |
| polarity of stripping of tobacco mosaic virus by alkali and sodium dodecyl sulfate. | | 1977 | 13534 |
| sequences of oligonucleotides prepared from tobacco mosaic virus ribonucleic acid. | | 1975 | 166485 |
| polarity of the rna in the tobacco mosaic virus particle and the direction of protein stripping in sodium dodecyl sulphate. | | 1976 | 6327 |
| [synthesis of virus-specific products following introduction of tobacco mosaic virus rna pereparations and the native virus into acetabularia]. | the possibility to synthesize the viral-specific products after microinjection of tobacco mosaic virus (tmv) preparations and the tmv rna into the single-celled seaweed acetabularia was studied. the accumulation of the newly synthesized protein and double-stranded rna 24 hours after injection of tmv rna and native virus preparations was demonstrated by immunological and immunofluorescent methods. the virus titer sharply dropped 3--4 hours after introduction into acetabularia and in 48 hours it r ... | 1978 | 96330 |
| a ph-dependent conformational change in the coat protein subunits from potato virus x. | both the circular dichroism and fluorescence spectra of the dissociated coat protein subunits from potato virus x changed substantially over the ph range 8 to 4, irreversible changes resulted below ph 4, with tyrosyl and tryptophanyl residues affected most. the titration curves show a pka of about 5.6 and do not require cooperative interactions between the coat protein subunits, thus they are in marked contrast to titrations of tobacco mosaic virus a-protein. the spectra of the intact virus were ... | 1976 | 10980 |
| dark field imaging of biological macromolecules with the scanning transmission electron microscope. | a scanning transmission electron microscope (stem) equipped with a field emission gun has been employed for the examination of biological macromolecules at high resolution. the quality of micrographs obtained with the stem is dependent upon the quality of the substrate used to support biological objects because the image contrast in dark field is proportional to the mass density of the specimen. in order to reduce deleterious effects of the substrates on the image quality, we have developed a me ... | 1979 | 35788 |
| antiphytoviral activity of 2,4 dioxo hexahydro triazine. | three treatments with 2,4 dioxo hexahydro triazine (dht) significantly reduced the concentration of potato virus x (pvx) in systemically infected tobacco plants. in hypersensitive plants dht caused a reduction in the number of local lesions produced by pvx. in systemic and hypersensitive hosts, treatment with dht resulted in a more or less marked reduction in the concentration of, and in the number of local lesions caused by, potato virus y (pvy), potato virus a (pva), tobacco mosaic virus (tmv) ... | 1979 | 42301 |
| enzymatic acylation of histidine to tobacco mosaic virus rna. | | 1976 | 5804 |
| [comparative study of the antiviral properties of histones of animal and plant origin]. | the antiviral properties of histones of animal (thymus) and plant (french beans) origin were studied in plants and with a plant virus, tobacco mosaic virus (tmv). histones of the thymus and french beans were shown to be able to inhibit tmv reproduction. the antiviral properties of histones were found to depend on their concentration, ph, and to be determined by the modes of their introduction into leaves. the manifestation of the antiviral properties of histones seems to require not only their d ... | 1978 | 34928 |
| the characterization of intermediates formed during the disassembly of tobacco mosaic virus at alkaline ph. | | 1978 | 23605 |
| appearances of microtubules after various fixative procedures, and comparison with the appearances of tobacco mosaic virus. | microtubules in crane-fly spermatids appeared altered when the glutaraldehyde-fixed cells were not postfixed with osmium tetroxide. the cytoplasmic microtubules were altered more than the doublet microtubules. addition of osmium tetroxide after dehydration did not produce appearances identical with those of microtubules postfixed directly after glutaraldehyde, and thus at least some alterations occurred during dehydration, possibly due to extraction of microtubule-associated lipid. the omission ... | 1975 | 54362 |
| importance of short-lived lymphocytes in the immune response. | lymphocytes are heterogeneous with respect to their life-span. typical b cells, bearing on their membranes immunoglobulin receptors, easily detectable by immunofluorescence, belong mainly to the long-lived population: this can be observed using combined autoradiography and immunofluorescence. however, when primed mice receive (-3h) thymidine before a boosting injection of tobacco mosaic virus (tmv), many plasma cells appearing in the spleen during the secondary response are labelled. in irradiat ... | 1975 | 48500 |
| electron microscopy of tobacco mosaic virus prepared with the aid of negative staining-carbon film techniques. | the negative staining-carbon technique has been applied to suspensions of freshly prepared type strain tobacco mosaic virus particles in high concentrations. electron microscope images show that paracrystalline arrays of the virus were formed, in which large areas of rods could be viewed along their long axes and in parallel arrays in horizontal positions. high-resolution micrographs showed the protein structure units in rods photographed in both vertical and horizontal orientations. | 1976 | 58964 |
| tobacco mosaic virus protein: kinetic and equilibrium studies on the ph-dependent transition. a-protein yields double disc. | | 1975 | 235923 |
| sharing of idiotypic specificities between different antibody populations from an individual rabbit. | rabbits hyperimmunized with tobacco mosaic virus synthesize very heterogeneous antibodies. despite this, specific anti-idiotypic sera recognizing a large part (70%) of these antibodies can be raised in rabbits matched for allotypic specificities a1, a2, a3, b4, b5, b6, c7, and b9. different rabbits synthesize antibodies with different idiotypic specificities. however, in the serum of a single rabbit antibody fractions of different isoelectric ph share some idiotypic specificities. the results sh ... | 1975 | 61876 |
| the formation of phenotypically mixed particles upon mixed assembly of some tobacco mosaic virus (tmv) strains. | | 1977 | 65827 |
| mixed infection with two tobamoviruses: the formation of particles containing the coat protein messenger rnas of either virus. | plants mixedly infected with the u2 strain of tobacco mosaic virus (t2mv) and sunnhemp mosaic virus (shmv) and grown at 35 degrees, yield particles of the same modal lengths (300 and 40 nm) as those found in plants singly infected with shmv, but not in plants infected with t2mv, which yield only the long particles. at least some of the particles produced in mixedly infected plants contain coat proteins of both viruses. when rnas from these particles are translated in vitro the coat proteins of b ... | 1976 | 67100 |
| electrophoretic light scattering on calf thymus deoxyribonucleic acdi and tobacco mosaic virus. | | 1975 | 235687 |
| isolation of specific antibody under conditions of low ionic strength. | specific rabbit and goat antibodies to tobacco mosaic virus, bovine serum albumin and human gamma globulin have been isolated by acid dissociation from the antigen in the absence of salt. maximum recovery of 96-100% of active antibody occurred at ph 2.8-2.9. the amount of antibody recovered within any given ph range was highly reproducible. the average antibody affinity was found to be correlated with the pth of dissociation and to decrease exponentially with the length of exposure to acid condi ... | 1977 | 68980 |
| immunochemical studies on the tobacco mosaic virus protein. | the decapeptide having the amino acid sequence thr-thr-ala-glu-thr-leu-asp-ala-thr-arg has been shown to be a major antigenic determinant of the tobacco mosaic virus protein in rabbits, mice and guinea pigs. the antigenic specificity of the decapeptide is attributed to its c-terminal tripeptide ala-thr-arg. although this tripeptide has no demonstrable binding with antibodies to the protein, its n-octanoylated derivative exhibits specific binding with antibodies as well as the capacity to elicit ... | 1978 | 82381 |
| location and encapsidation of the coat protein cistron of tobacco mosaic virus. a bidirectional elongation of the nucleoprotein rod. | the coat protein cistron of tobacco mosaic virus has been located on the viral rna starting between 975 and 1050 nucleotides from the 3'-hydroxyl end. this locates its 5' end close to the origin for virus assembly, where the first protein disk interacts with rna. it also means that the coat protein mrna must have a short 5'-untranslated tail and a long (over 500 nucleotides) 3' one. the recovery of characteristic oligonucleotides in nuclease-protected rods during the growth from rna and a protei ... | 1979 | 108098 |
| sequence of 1000 nucleotides at the 3' end of tobacco mosaic virus rna. | the sequence of 1000 nucleotides at the 3' end of tobacco mosaic virus rna has been determined. the sequence contains the entire coat protein cistron as well as regions to its left and right. sequence characterization was by conventional methods for use with uniformly 32p labeled rna complemented by newer methods for in vitro 5' and 3' 32p end-labeling of rna and its subsequent rapid analysis. the noncoding region separating the coat protein cistron from the 3' terminus is 204 residues long and ... | 1979 | 109810 |
| letter: hysteresis of proton binding to tobacco mosaic virus protein associated with metastable polymerization. | | 1975 | 240942 |
| states of aggregation of the dahlemense strain of tobacco mosaic virus protein and their relation to crystal formation. | | 1975 | 240945 |
| infectivity suppressing and virus-binding activities of a membrane material isolated from tobacco leaves. | tmv binding substance (r) was isolated from a tobacco leaf membrane fraction and was purified by extraction with organic solvents and by column chromatography. experimental results suggest that the binding of r with tmv results in inactivation of tmv. when tobacco leaves were inoculated with the r-tmv complex, it was found that the formation of polysome containing infecting viral rna was inhibited. model experiments showed that the mode of r-tmv adsorption to the membrane is different from that ... | 1979 | 94422 |
| tobacco mosaic virus rna carries 5'-terminal triphosphorylated guanosine blocked by 5'-linked 7-methylguanosine. | | 1975 | 170129 |
| characterization of long guanosine-free rna sequences from the dahlemense and u2 strains of tobacco mosaic virus. | four naturally occurring strains of tobacco mosaic virus, u2, dahlemense, cv4, and the bean form of tobacco mosaic virus, were tested for the existence of long t1 rnaase oligonucleotides analogous to the oligonucleotide omega found in the common or u1 strain of tobacco mosaic virus and which makes up the 5' non-coding region of the rna molecule. u2 and dahlemense rna were each found to contain this type of long t1 rnaase oligonucleotide with chain lengths of 54 and 74--77 residues, respectively. ... | 1979 | 111935 |
| hapten-sandwich labeling. ii. immunospecific attachment of cell surface markers suitable for scanning electron microscopy. | a hapten-sandwich procedure has been used for immunospecific labeling of cell surface antigens with markers visible by scanning electron microscopy. antihapten antibody was used to link hapten-modified tobacco mosaic virus, bushy stunt virus, or hemocyanin to hapten-modified human erythrocytes. the antihapten antibody bridge was also used to link the hapten-virus marker to hapten-modified antibodies against mammary tumor virus on mouse mammary tumor cells, or against immunoglobulin receptors on ... | 1975 | 163829 |
| mechanism of self-assembly of tobacco mosaic virus protein. i. nucleation-controlled kinetics of polymerization. | | 1979 | 34729 |
| mechanism of self-assembly of tobacco mosaic virus protein. ii. characterization of the metastable polymerization nucleus and the initial stages of helix formation. | | 1979 | 34730 |
| importance of 5'-terminal blocking structure to stabilize mrna in eukaryotic protein synthesis. | the 7-methylguanylic acid residue confronting the 5'-terminal nucleotide of mrna through two pyrophosphate linkages was completely removed by tobacco pyrophosphatase from mrnas of cytoplasmic polyhedrosis virus, tobacco mosaic virus (viral rna), and globin without any scission in the inner part of the rna chain. protein synthesis ability in a wheat germ cell-free system was lost after this treatment of all three kinds of mrna. the initiation complexes for protein synthesis of these three rnas we ... | 1977 | 197518 |
| a 13c and 1h nmr study on rod-like polymerization of tobacco mosaic virus protein. | | 1978 | 29780 |
| the 5' end group of tobacco mosaic virus rna is m7g5' ppp5' gp. | rna extracted from csc1-purified virions of tobacco mosaic virus is shown to give rise to an unusual nucleotide on digestion which rnaase t2, in addition to the four major nucleotides. this minor component has the electrophoretic characteristics of a phosphorylated end group, but is partially resistant to bacterial alkaline phosphatase. it is, however, a substrate for venom phosphodiesterase or nucleotide pyrophosphatase, yielding products which imply the structure m7g5'ppp5'gp. tmv rna, like ma ... | 1975 | 168558 |
| enzymatic removal of the 5'-terminal methylated blocked structure of tobacco mosaic virus rna and its effects on infectivity and reconstitution with coat protein. | | 1976 | 182554 |
| [study of the conformational mobility of globular proteins by pulse methods of nmr]. | the protein spin-echo decay and recovery of longitudinal magnetization were studied in seven globular proteins: cytochrome c, ribonuclease, lysozyme, dna, hemoglobin, serum albumin and gamma-globulin in d2o solutions. for comparison the tobacco mosaic virus (tmv) protons in d2o solutions were also investigated. the spin-echo decay of all 7 proteins can be separated into three components: a slowly decaying component with an amplitude of about 10% of the amplitude of the total signal, intermediate ... | 1978 | 207975 |
| a spin label epr study of tobacco mosaic virus protein. | | 1978 | 202492 |
| [on the antiviral effect of a triazole compound (author's transl)]. | 4-[hydroxy-3-piperid-n-yl-prop-1-yl]-5-methyl-2-phenyl-triazole (hmpt) reduced the plaque formation caused by m 12, f 2, and q beta and retarded the liberation of phages. the concentration of tobacco mosaic virus in primarily infected tobacco leaves was decreased. hmpt inhibited the development of local lesions. free phages and tmv particles werenot influenced by hmpt. | 1979 | 398649 |
| phenylalanine ammonia-lyase in tobacco mosaic virus-infected hypersensitive tobacco. density-labelling evidence of de novo synthesis. | a strong increase in phenylalanine ammonia-lyase (ec 4.3.1.5) activity occurs in tobacco mosaic virus-infected tobacco leaves developing necrotic local lesions. comparison of physicochemical properties of the partially purified enzymes extracted from healthy and infected leaves showed that the hypersensitive reaction leads to an increase in the pool size of the same active enzyme molecules as those present in non-infected material. the molecular mechanism of enzyme formation was investigated by ... | 1977 | 411516 |
| cytokinin activity in the rna of tobacco mosaic virus. | | 1979 | 425329 |
| studies on spin labeled ribonucleic acids encapsulated by viral proteins. | spin labeled poly ra (sl-poly ra) was encapsulated by the coat proteins of two plant viruses having different morphologies: tmv, a rigid rod and ccmv, an icosahedral sphere. electron microscopy showed that the resultant particles were morphologically similar to the parent virus from which the coat protein was obtained. encapsulation produced progressive immobilization of the spin label. the motion of the spin label attached to tmv-sl-poly ra appears anisotropic with a correlation time about the ... | 1978 | 214764 |
| a poly(u) polymerase in tobacco leaves. | a poly(u) polymerizing enzyme has been found in healthy and tobacco mosaic virus-infected tobacco leaves and has been partially purified by affinity chromatography on a gel prepared from agarose with chemically coupled rna. the enzyme is stimulated by mn-2+ and dependent on a polynucleotide, preferentially poly(a). the synthesis proceeds optimally at ph 7.6 and 25 degrees c. the enzyme is highly specific for utp and is inhibited by other ribonucleoside triphosphates. the product was partly sensi ... | 1975 | 235994 |
| effects of alkylation of phosphodiesters and of bases of infectivity and stability of tobacco mosaic virus rna. | upon ethyl nitrosourea treatment of rna of tobacco mosaic virus, up to four phosphodiester groups may be alkylated per molecule without chain breakage, as shown be sucrose gradient centrifugation. this indicates that ribophosphotriesters are quite stable. however, when this alkylation reaction is of longer duration and 6 to 10 triesters are formed, then an average of 1 to 2 breaks occurs and little or no intact rna can be isolated. methyl nitrosourea is less effective in forming triesters (about ... | 1975 | 237271 |
| a specific effect of calcium ion on the polymerization-depolymerization of tobacco mosaic virus protein. | | 1975 | 239636 |
| topography of a flexible ribonucleoprotein helix: protein-protein contacts in sendai virus nucleocapsids. | contacts among the three polypeptide species in the flexible helical nucleocapsids of a paramyxovirus were examined with bifunctional protein cross-linking reagents. polypeptides l and p, minor components of sendai virus nucleocapsids implicated in viral rna polymerase activity, were efficiently cross-linked into large complexes, indicating that they enjoy abundant contacts with neighboring protein molecules in the helix. less reactivity was found in the case of the major structural polypeptide, ... | 1979 | 225539 |
| assembly of tobacco mosaic virus in vitro: elongation of partially reconstituted rna. | it was reported that the rate of elongation of partially reconstituted rna, if prepared without centrifugation, showed dependency upon the state of protein aggregation like that found when free rna was used as the nucleic acid source [butler, p. j. g. (1974) j. mol. biol. 82, 333-341]. butler concluded from this result that disks are the kinetically favored protein source for the elongation of the tobacco mosaic virus rod. we show that partially reconstituted rna prepared without centrifugation ... | 1977 | 265520 |
| inhibitory effect of methylated derivatives of guanylic acid for protein synthesis with reference to the functional structure of the 5'-'cap' in viral messenger rna. | guanylic acid modified variously with methyl groups on base or sugar moieties were synthesized chemically and their inhibitory effects on protein synthesis were tesetd in a wheat germ cell-free system using mrnas from cytoplasmic polyhedrosis virus and tobacco mosaic virus. the confronting dinucleotide m7g5' pppa that corresponds to the most simple 'cap' structure of an eukaryotic mrna is a strong inhibitor of protein synthesis, but non-methylated g5' pppa or g5' ppa is not inhibitory. the stron ... | 1979 | 226144 |
| [study of protein-nucleic reactions in tobacco mosaic virus by the spin label and fluorescence technics]. | | 1979 | 219907 |
| kinetics of biphasic reconstitution of tobacco mosaic virus in vitro. | the kinetics of the in vitro reconstitution of tobacco mosaic virus from its rna and protein were studied by measuring the increase in turbidity, the development of ribonuclease-resistant infectivity, the emcapsidation of the terminal ends of the rna, and the growth of rod length. the results showed that the reconstitution reaction consists of two processes in which the direction, timing, and rate of assembly are different. rapid elongation of particles toward the 5' end of the rna proceeds in t ... | 1978 | 273903 |
| inside-out model for self-assembly of tobacco mosaic virus. | incompletely reconstituted particles of tobacco mosaic virus treated with moderate concentrations of dimethylsulfoxide prior to electron microscopy have two visible tails of unencapsidated rna, a long one and a short one. the short tail has a constant length of 720 +/- 80 nucleotides in incomplete particles of diverse size and probably corresponds to the 3'oh end of the rna. the length of the long 5' tail is inversely related to the length of the unfinished rod. surprisingly, both tails appear t ... | 1977 | 264669 |
| kinetics and mechanism of tobacco mosaic virus assembly: direct measurement of relative rates of incorporation of 4s and 20s protein. | the mechanism of assembly of tobacco mosaic virus has been investigated under conditions in which the rates of incorporation of the 4s and 20s proteins can each be directly measured by analytical centfrifugation. under these conditions, ph 6.5, 6.5 degrees c, 0.10 m ionic strength potassium orthophosphate, the protein can be made to exist as a metastable 20s aggregate that is necessary for efficient reconstitution. the overall assembly process consists of an initiation (nucleation) reaction that ... | 1979 | 288062 |
| idiotypic regulation of the immune system. common idiotypic specificities between idiotypes and antibodies raised against anti-idiotypic antibodies in rabbits. | anti-idiotypic antibodies (ab2) were raised in allotype-matched rabbits against anti-carbohydrate or anti-tobacco mosaic virus antibodies (ab1). several ab2 were purified and injected into a third series of rabbits iii which synthesized antiantiidiotypic antibodies (ab3). antigen was then given for the first time in those rabbits who had synthesized ab3. the specific antibody synthesized in rabbits iii was called ab1'. anti-idiotypic antibodies were raised against purified ab3 antibodies (ab4). ... | 1979 | 312906 |
| polar uncoating of tobacco mosaic virus (tmv) with dimethylsulfoxide (dmso) and subsequent reassembly of partially stripped tmv. | increasing concentrations of dimethylsulfoxide (dmso) strip tobacco mosaic virus (tmv) stepwise from the 3'end. the rna tail increases in length up to 2,000 nucleotides (nu) reaching a region of very strong protein-rna affinity. thereafter, uncoating occurs from the other end and produces a second rna tail 500 nu long. further stripping of tmv proceeds from both ends, the long tail increasing in length up to 4,000 nu and the short one increasing more moderately and remaining below 2,000 nu. the ... | 1979 | 286871 |
| tactoidal state and phase transitions in systems of linear polymers of variable length. | the tactoidal state in systems containing long, rod-like molecules consists of partially aligned solute molecules in equilibrium with and at a concentration not much higher than that in the conjugate isotropic phase. under the liquid lattice model of flory [proc. r. soc. london ser. a, (1956) 234, 73-89], as well as under other models, tactoid formation by molecules of fixed axial ratio depends on nonideality induced by excluded volumes; the process is wholly entropy driven and requires no direc ... | 1979 | 288061 |
| binding of ribosomes to 5'-terminal leader sequences of eukaryotic messenger rnas. | tobacco mosaic virus and turnip yellow mosaic virus genome rnas, which have long (greater than or equal to 69 nucleotides) 5'-terminal leader sequences preceding the aug initiation codon, can form disome initiation complexes when incubated with a wheat germ extract and sparsomycin. in tobacco mosaic virus rna, whereas one ribosome in such complexes presumably occupies the aug-containing initiation site, the other is located within the rna leader sequence. the results favor a model of eukaryotic ... | 1979 | 290990 |
| electrophoretic analysis of the molecular weight of murine mammary tumor virus rna. | molecular weight determinations of native and subunit rnas of murine mammary tumor virus (mumtv), a type b oncornavirus, were performed by polyacrylamide gel electrophoresis and compared with molecular weights of well-characterized avian cellular rnas and tobacco mosaic virus rna. from extrapolations of semilog plots of the molecular weights of the standard rnas versus relative electrophoretic mobilities and ferguson plots, the subunit and native rnas of mumtv were found to possess molecular wei ... | 1977 | 195092 |
| reconstitution of tobacco mosaic virus rods occurs bidirectionally from an internal initiation region: demonstration by electron microscopic serology. | rna of a common strain of tobacco mosaic virus was sequentially reconstituted first with protein of the same strain and then with protein of a tomato strain. the reconstituted particles were treated with specific antibodies against the two strain particles and were examined electron microscopically to locate the regions of rods encapsidated with the respective proteins. the results demonstrated that reconstitution starts at an internal region of the rna about 830 nucleotides from an end that rec ... | 1977 | 325560 |
| the structure of cytochrome b562 from escherichia coli at 2.5 a resolution. | the structure of cytochrome b562 from escherichia coli has been determined at 2.5 a resolution by x-ray diffraction methods. protein phases were computed by the single isomorphous replacement method with anomalous scattering measurements from the native and uranyl acetate-substituted crystals. the electron density was averaged about the noncrystallographic 2-fold axis relating 2 molecules in the triclinic unit cell. the protein consists of four nearly parallel alpha helices and represents a new ... | 1979 | 368073 |
| combined microspectrophotometry and automated quantitative autoradiography applied to the analysis of the plant cell cycle. | two methods, which relate grain number to cell cycle phase in feulgen-stained autoradiographic preparations, have been developed and compared. both methods automate grain number estimations, one by taking integrated absorbance measurements at different wavelengths, the other by measuring absorption at a single wavelength before and after chemical removal of silver grains. with tritium-labelled tobacco mosaic virus as a probe, a quantitative analysis has been made of the binding of virus particle ... | 1979 | 393709 |
| a modification of the polyethylene glycol technique for the purification of small quantities of tobacco mosaic virus. | an adaptation of the polyethylene glycol method for the purification of tobacco mosaic virus (sunnhemp strain) from small (2 g) samples of french bean lamina is described. the virus can be precipitated from 1-2 ml of clarified sap by the addition of an equal volume of 8% polyethylene glycol 6000 (w/v) (peg), and pelleted by centrifugation for 10 min at 1,8000 x g. details are given of tests which establish that the purity and quality of the virus obtained by the small-scale method are as good as ... | 1979 | 393959 |
| efficeint transcription of rna into dna by avian sarcoma virus polymerase. | the dnaase digestion end-product of calf thymus dna contains oligonucleotides that will function as primers for the efficient transcription into dna of many naturally-occurring rna's by purified avian sarcoma virus rna-directed dna polymerase. the labeled dna transcripts so obtained are valuable as probes for molecular hybridization studies. typical applications of the method include the efficient transcription into dna of 18 and 28 s rrna as well as the rna's of avian sarcoma virus, polio virus ... | 1976 | 183818 |
| translation of tobacco mosaic virus rna in acetabularia cell cytoplasm. | isolated acetabularia nuclei were microinjected with tobacco mosaic virus rna and then implanted into an anucleate posterior fragment of an acetabularia cell. injected rna was translated in the acetabularia cytoplasm from the first to twelfth day after implantation of the nuclei. the production of specific virus proteins was detected and localized in the acetabularia cytoplasm by an immunofluorescence precipitation technique. | 1978 | 363289 |
| location of the sequences coding for capsid proteins vp1 and vp2 on polyoma virus dna. | the 19s and 16s polyoma virus late mrnas have been separated on sucrose-formamide density gradients and translated in vitro. the 16s rna codes only for polyoma capsid protein vp1, while the 19s rna codes in addition for capsid protein vp2. since the 19s and 16s species have been previously mapped on the viral genome, these results allow us to deduce the location of the sequences coding for vp1 and vp2. comparison of the chain lengths of the capsid proteins with the size of the viral mrnas coding ... | 1976 | 186193 |
| protein-rna interactions during tmv assembly. | a review of the structural studies of tobacco mosaic virus (tmv) is given. tmv is essentially a flat helical microcrystal with 16 1/3 subunits per turn. a single strand of rna runs along the helix and is deeply embedded in the protein. the virus particles form oriented gels from which high-resolution x-ray fiber diffraction data can be obtained. this may be interpreted by the use of six heavy-chain derivatives to give an electron density map at 0.4 nm resolution from which the rna configuration ... | 1979 | 397974 |
| determination of avidity of anti-viral antibodies at 50% binding of antibody. | binding studies with tobacco mosaic virus and specific igg and fab' fragments were done under conditions of 50% binding of antibody. when the log of the concentration of antigen sites required to bind 50% of the available antibody was plotted against the log of bound sites, a line was obtained which had a slope varying between 0 and 1. instead of using the slope of this line as an index of avidity of the antiserum, it is suggested that the calculation k0 values over a range of reactant concentra ... | 1979 | 458165 |
| binding of oligonucleotides to the disk of tobacco-mosaic-virus protein. | the trinucleoside diphosphate a-a-g and the hexanucleotide fraction from a ribonuclease i digest of yeast rna have been soaked into crystals of the disk aggregate of tobacco mosaic virus protein. at high concentrations these cause disruption of the crystal, probably by mimicking the normal nucleation of assembly. at lower nucleotide concentrations the crystals remain intact and the differences caused by nucleotide binding have been studied by x-ray diffraction. the most obvious change is an upwa ... | 1979 | 428385 |
| distance constraints on macromolecular conformation. | many physico-chemical studies are made on proteins to determine something of their solution conformation. for example the coat protein of tobacco mosaic virus has been subjected to more non-crystallographic experimental studies to determine its native conformation than perhaps any other protein. yet the sum of the experimentally determined constraints on its tertiary structure are surprisingly inadequate to fix its conformation. we are able to detect and remove minor inconsistencies in the data ... | 1979 | 429105 |
| [model for tobacco mosaic virus assembly in vitro: specific dislocation by cooperative single-letter purine recognition and non-cooperative rna "locking" between subunit layers]. | a model of the molecular mechanism of tobacco mosaic virus (tmv) assembly in vitro is proposed. the model is based on the assumption that on interaction of tmv rna chain with a double protein disk two different types of structural alterations occur in the protein subunits: "dislocating alterations" leading to screw dislocation of the disk into a helix fragment and "locking alterations" leading to locking of the rna chain between the subunits layers. during initiation of tmv assembly the dislocat ... | 1979 | 470937 |
| a temperature-sensitive mutant of tobacco mosaic virus deficient in synthesis of single-stranded rna. | | 1979 | 433149 |
| disassembly of tobacco mosaic virus by membrane lipid isolated from tobacco leaves and polyornithine. | in vitro disassembly of tobacco mosaic virus (tmv) virions occurred in the presence of both polyornithine and a lipid fraction isolated from tobacco leaf membrane. the latter could be replaced by lecithine. disassembly of 10 microgram of tmv virions was attained in the presence of a 500-mg leaf equivalent of membrane lipid and 20 microgram of polyornithine in 1 ml of 0.01 m tris-hcl buffer, ph 7.4 at 30 c. similarity and dissimilarity between the in vitro disassembly and the in vivo uncoating m ... | 1979 | 530101 |
| carbon-13 nuclear magnetic resonance studies on tobacco mosaic virus and its protein. | fourier transform nuclear magnetic resonance studies on 12% 13c-enriched tobacco mosaic virus (tmv) and its rod-like protein oligomers in solution with molecular weights up to 42 x 10(6) are reported. in the virus approximately 17% of the carbons of the protein subunit have line widths of less than or equal to 300 hz and t1 less than or equal to 1 s and are concluded to be mobile with more than one degree of freedom of internal rotation about a carbon--carbon bond. in the rodlike polymer of tmv ... | 1979 | 486407 |
| light scattering of aqueous solutions of dna, poly(acrylic acid), and tobacco mosaic virus under alternating electric field. | | 1979 | 526552 |
| structural comparisons of the aggregates of tobacco mosaic virus protein. | the coat protein of tobacco mosaic virus forms numerous aggregates, including the small a-protein, the disk, and two helical forms. the structures of the disk, the helical protein forms, and the virus are compared. most of the differences are in the conformation of the chain between residues 89 and 113, which lies in the region of protein at the center of the virus, inside the rna. it is disordered in the disk, but has a fixed conformation in the virus and the protein helices. the differences be ... | 1979 | 544935 |
| comparison of the relationships of southern bean mosaic virus and the cowpea strain of tobacco mosaic virus with the bean leaf beetle. | | 1978 | 563640 |
| fluorescent study of tobacco mosaic virus protein. | protein fluorescence properties of tobacco mosaic virus [3 trp residues per monomer (positions 17, 52, 152)] and of two tobacco mosaic virus mutants [green tomato atypical mosaic virus, 2 trp (52, 152) and cucumber virus4, 1 trp (unknown position)] have been studied. emission spectra, fluorescence quantum yields and lifetimes were determined. results showed that protein fluorescence is due to buried trp only, except for the cucumber virus4 strain, in which tyr also contributed to the emission. c ... | 1977 | 588584 |
| in vitro methylation of tobacco mosaic virus rna with ribothymidine-forming trna methyltransferase. characterization and specificity of the reaction. | a novel method has been developed for the detection and study of trna-like moieties in viral rnas. tobacco mosaic virus rna is an acceptable substrate for crude escherichia coli ribothymidine-forming trna methyltransferase. under optimum reaction conditions at least 85% of the methylation product is ribothymidine (rt). the reaction is essentially quantitative, 1 mol of rt being formed per mol of tobacco mosaic virus rna. the optimum reaction conditions include the presence of 6.6 micrometers s-a ... | 1978 | 361090 |
| double-stranded rna is present in extracts of tobacco plants infected with tobacco mosaic virus. | serologically specific electron microscopy was used to detect double-stranded rna in extracts of tobacco infected with tobacco mosaic virus. assays were made immediately after extraction, without purification, concentration, or treatment with phenol or detergent. this indicates that the double-stranded rna is native and is not an artifact induced by purification methods. | 1978 | 622553 |
| the influence of protoplast concentration on retention of tobacco mosaic virus by tobacco protoplasts. | | 1978 | 622812 |