Isolation of the protein dimers from shoots. Chitinase activity profiles of the fractions collected following Rotofor purification from proteins obtained from control (A) or Trichoderma-treated (B) plants. The pI of several fractions is indicated. Triangles and circles are MUA and MUB tests, respectively. Gel analysis for the different stages of dimer purification is presents in (C). Activity staining for Rotofor fractions #4 from control and Trichoderma-treated plants (Native gels) is shown on the 1st panel on the left; on the 2nd panel is a coomassie staining of a sample of the same fractions run on SDS-PAGE. The active bands were sliced out and eluted from the native gels. A sample of these eluted proteins was analyzed on SDS-PAGE with protein-treatment of 55°C, silver stained and is shown on the 3rd panel indicating that they are electrophoretically pure. On the 4th panel (right side)- after boiling, the purified proteins dissociated into smaller proteins at the size of the components of the dimeric proteins as identified by LC/MS/MS (arrows). Molecular size markers (marked with asterisks): 106, 93, 52, 32, 28, and 18 kDa.