FIG. 9.

Analysis of N protein multimerization by DSP cross-linking. Virus particles or cells expressing either viral or recombinant N proteins were cross-linked with 2 mM DSP for up to 1 h and solubilized in RIPA buffer. The lysates were boiled in standard SDS sample buffer under nonreducing conditions and were separated by SDS-PAGE followed by immunoblot analysis using N-specific rabbit antibody and the alkaline phosphatase-conjugated secondary antibody against rabbit immunoglobulin G. (A) Kinetic studies of purified virus samples treated with DSP and cross-linked for increasing periods of time. (B) Cross-linked N protein point and deletion mutants probed with N-specific rabbit antibody. The arrows indicate oligomeric forms of the N protein. WT, wild type. Molecular mass markers (M) in kilodaltons are shown on the left.