1989 Volume 55 Issue 5 Pages 586-593
We examined the effects of concentration methods, extraction buffers, clarification reagents, and resuspension buffers on virus yield and purity by using SDS-polyacrylamide gel electrophoresis (SDS-PAGE), so as to establish optimal purification procedures of zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus 2 (WMV2), and the watermelon mosaic virus 1 strain of papaya ringspot virus (PRSV-W). We then investigated the physicochemical properties of the three viruses. SDS-PAGE proved very useful to monitor virus purification in a small scale. The three viruses were purified with similar yields of 5-10mg per 100g of infected pumpkin leaves by the respective optimal methods. The procedures basically involved clarification with Triton X-100, differential centrifugation using a 20% sucrose pad, and 20-50% sucrose density gradient centrifugation. From WMV2 and PRSV-W purified preparations, capsid protein (CP) of 34, 000 (34K) was predominantly detected in addition to minor degradation products of 27K to 33K, respectively. A breakdown product of 28K was, however, as detectable as intact CP of 33K from ZYMV purified preparation. The RNAs of WMV2 and PRSV-W, which were a little larger than ZYMV RNA, were indistinguishable in size as evaluated with 1.7% agarose gel electrophoresis in denaturing conditions.