Crystallization of a Protein from Poliomyelitis Infected Mouse Brain

Abstract

Poliomyelitis infected brains were frozen and kept at or below 0[degree] throughout the procedure. Brains were thawed and extracted with saline, centrifuged and supernatant fluid shaken with an equal volume of ether. In separation the lower layer contains most of the virus. Supernatant I was kept separate. The precipitate was re-suspended in saline, pH adjusted to 8, mixed and centrifuged (supernatant II). Supernatant I and II were mixed, precipitated with 1.6 [image] (NH4)2S04, centrifuged and ppt. discarded. Supernatant was reprecipitated with 2.3 [image] (NH4)2SO4, ppt. suspended in physiol. saline and dialyzed against saline. The soln. was then brought to pH 4.3 and ppt. discarded. To the clear fluid was added iV/100 acetic acid until ppt. appeared. One of these conglomerates was separated, washed in A71000 acetic acid and dissolved in dilute NaOH. It proved highly infective for mice, producing typical paralytic symptoms of poliomyelitis after intracerebral inoculation, in 14-72 hrs.