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T R Doel

Publications and source records attributed to T R Doel.

48 records · Page 3Linked to original sources

Thermal stability of foot-and-mouth disease virus.

The thermal stabilities of 146S component of seven strains of foot-and-mouth disease virus were found to differ considerably. Inactivation of infectivity with acetylethyleneimine (AEI) reduced the thermal stabilities of all but one of the viruses. Treatment of AEI inactivated and control virus preparations with glutaraldehyde stabilized 146S particles to a considerable extent, whereas treatment with dimethyl suberimidate was less effective. In similar experiments with 75S, natural empty particles, the thermal stabilities were lower than those of the corresponding 146 S particles. Treatment of 75S particles with AEI appeared to have no direct effect on the protein-protein interactions involved in 75S capsid integrity. As with 146S particles, glutaraldehyde stabilized 75S particles.

Aphthovirus↗

Observations and implications of proteolysis in preparations of foot-and-mouth disease virus.

The integrity of the VP1 protein of foot-and-mouth disease virus was assessed by polyacrylamide gel electrophoresis (following storage at 4 degrees C of conventional tissue culture preparations and concentrated preparations of the virus. There was little evidence of VP1 degradation in tissue culture filtrates whereas considerable degradation was observed throughout a range of different concentrates. The use of the proteolytic enzyme inhibitor 'Trasylol' appeared to inhibit VP1 degradation in some virus preparations. Vaccination experiments with guinea pigs indicate that cleavage of O BFS 1860 virus by a range of proteolytic enzymes was always associated with a lowered stimulation of neutralising antibody and total antibody. Experiments with six other strains treated with trypsin gave similar results to those obtained with O BFS 1860.

Aphthovirus↗

Biochemical aspects of variation in foot-and-mouth disease virus.

The biochemical basis for variation in foot-and-mouth disease virus (FMDV) has been explored by analysis of the virus RNA and the virus-induced and structural proteins of three isolates of the virus. Two of the isolates were from serotype A and the third was from serotype O. Hybridization studies of the RNAs showed greater than 80% homology between the two type A viruses and about 65% homology between the two type A viruses and the virus of type O. The ribonuclease T1 maps of the three viruses gave distinct patterns typical of FMDV, but did not show that any two of the three viruses were more closely related. The virus-induced primary translation products, P88, P52 and P100 isolated from infected cells, were compared by tryptic peptide analysis. Combinations of 3H- and 14C-leucine-labelled polypeptides were hydrolysed with trypsin and resolved on an ion-exchange column. Much greater differences were found in P88 than in P52 or P100, indicating that the major variation occurs in the region of the genome coding for the structural proteins. Similar analysis of combinations of the structural proteins of the three viruses showed that there were differences in VP1, VP2 and VP3 and these results were supported by those obtained by PAGE analysis of the Staphylococcus aureus V8 protease cleavage products.

Aphthovirus↗

Purification and identification of the RNA-dependent RNA polymerase of foot-and-mouth disease virus.

The RNA-dependent RNA polymerase induced in BHK 21 cells by infection with foot-and-mouth disease virus has been isolated from the replication complex. It contains a major, virus-coded protein with mol. wt. 56 000 which appears from serological studies and tryptic peptide mapping to be the same as the virus infection associated (VIA) antigen and the protein P56 found in cells infected with the virus. Other virus coded proteins and a host cell protein were present in the partially purified replication complex but were removed by digestion with ribonuclease T1, leaving only the major virus coded protein. The tryptic peptide maps of the VIA antigen of the seven serotypes of the virus were similar, suggesting a high level of conservation in that region of the genome coding for the RNA polymerase of each type.

Animals↗

Tryptic peptide analysis of the structural proteins of vesicular stomatitis virus.

The individual structural polypeptides of vesicular stomatitis virus have been examined by tryptic peptide analysis of 35S-methionine preparations labelled in vivo and 125I-preparations labelled in vitro. Isolates of the two classical serotypes of the virus (Indiana and New Jersey) and of a sub-type of the Indiana serotype, Brazil virus, were compared. The study showed that the major internal proteins of all three viruses gave similar maps, whereas the surface glycoproteins gave distinct maps that had very few spots in common. The map of the glycoprotein of Brazil virus, which has been shown previously to be more closely related serologically to Indiana virus than to New Jersey virus, did not show any greater similarity to the Indiana virus than to the New Jersey virus glycoprotein. On the other hand, peptide maps of the nucleoprotein and matrix protein showed Indiana and Brazil viruses to be more closely related to each other than to New Jersey virus.

Amino Acids↗

A model for vesicular exanthema virus, the prototype of the calicivirus group.

The structure of vesicular exanthema virus, the prototype member of the calicivirus group, has been studied in more detail. The RNA comprises 18% of mol. wt. of about 2.8 x 10(6), based on polyacrylamide gel electrophoresis experiments in the presence of formaldehyde. The virus contains one major polypeptide, mol. wt. 70 x 10(3) as determined by polyacrylamide gel electrophoresis and by chromatography on Sepharose 6B in the presence of 6 M-guanidine. Further evidence for the presence of a single major polypeptide was obtained by tryptic peptide analysis of 35S-methionine labelled virus. The mol. wt. of a protein oligomer produced by adjusting the pH of virus suspensions to 3.5 was c. 200 x 10(3). On the basis of these data we propose a T = 3 model for the virus capsid incorporating 180 copies of the virus protein.

Animals↗

A re-appraisal of the biochemical map of foot-and-mouth disease virus RNA.

The proteins induced by infection of BHK 21 cells with foot-and-mouth disease virus have been compared by tryptic peptide analysis. The results indicate that there are three primary products 5'--P88, P52, P100--3'. The polypeptide P56, which we considered previously to be a primary product, is derived from the region of the genome that codes for P100. The results indicate that there are alternative cleavage pathways of P100, the polypeptide coded for by the 3' end of the genome.

Aphthovirus↗