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Inhibition of type 5 adenovirus infectivity by periodate oxidation
1Laboratoire d'Immunochimie Inserm, Faculté de Médecine Lyon Sud, Université Claude Bernard Lyon I, Oullins, France.
Abstract:
Periodate oxidation of purified type 5 Adenovirus (Ad5) led to a mean loss of infectivity of 6.84 logs. There were no significant differences in adsorption and penetration between oxidized and mock-oxidized virus. However, after infection with oxidized virus, no synthesis of viral structural proteins could be detected and a 78.5% inhibition of viral DNA synthesis was observed. Labelling experiments performed by treating oxidized and mock-oxidized virus with tritiated sodium borohydride revealed that the fiber glycoprotein was one of the proteins labelled in oxidized virus whereas no labelled proteins were detected in non oxidized virus. In addition, it was found that one mol of formaldehyde generated during oxidation of sugar residues was bound per 500 base pairs in oxidized virus. One consequence of this in situ generation of formaldehyde is the formation of DNA-protein crosslinks. The DNA so crosslinked showed different patterns of restriction fragments with endonucleases such as Hpa I, Hind III and Kpn I but not with Xho I.
Insights
Periodate oxidation significantly reduces adenovirus type 5 infectivity by damaging viral structural proteins and inhibiting DNA synthesis. This process generates formaldehyde, causing DNA-protein crosslinks and altering DNA restriction patterns.
Area of Science:
- Virology
- Biochemistry
- Molecular Biology
Background:
- Adenovirus type 5 (Ad5) is a common human pathogen.
- Understanding Ad5 inactivation mechanisms is crucial for antiviral strategies.
Purpose of the Study:
- To investigate the effects of periodate oxidation on Ad5 infectivity and replication.
- To identify specific viral components affected by oxidation.
Main Methods:
- Periodate oxidation of purified Ad5.
- Infectivity assays, adsorption and penetration studies.
- Viral protein and DNA synthesis analysis.
- Tritiated sodium borohydride labeling.
- Restriction endonuclease digestion of viral DNA.
Main Results:
- Periodate oxidation caused a 6.84-log mean loss of Ad5 infectivity.
- Oxidation did not affect virus adsorption or penetration.
- No viral structural protein synthesis was detected post-infection with oxidized virus.
- A 78.5% inhibition of viral DNA synthesis was observed.
- The fiber glycoprotein was labeled in oxidized virus, indicating its modification.
- Formaldehyde generated during oxidation formed DNA-protein crosslinks, altering DNA restriction fragment patterns.
Conclusions:
- Periodate oxidation inactivates Ad5 by targeting structural proteins like the fiber glycoprotein and disrupting viral DNA replication.
- In situ formaldehyde generation leads to DNA-protein crosslinks, contributing to viral inactivation.