The effects of hydrogen ions on the morphology and infectivity of rhinovirions

Purified human rhinovirus type 14 has been subjected to acid and alkaline degradation and the effects of hydrogen ions on particle morphology and infectivity are being studied. Considerable morphological degradation of the capsid occurred by pH 5.5. Breakdown may be by loss of discrete capsomere groups accompanied by release of the viral genome in the form of a ribonucleoprotein strand. Examination of virions prepared for electron microscopy by the “critical point” procedure which results in essentially 3 dimensional specimens confirms this finding. Under alkaline conditions there is very little loss of infectivity up to pH 9.8. There is a precipitous loss in infectivity at around pH 10.9 accompanied by complete break up of viral capsid morphology.