Fig. 5

Comparison of expression level, solubility and activity of the cold-shock inducible, recombinant chitinase. a A representative SDS-PAGE gel showing the total protein produced (T) and the soluble fraction (S) in lysed Rosetta2(DE3)pLysS extracts of MZ0009 expressed from the pCold-vector suite. Asterisks indicate the presence of recombinant proteins of theoretical expected mass (given below figure). M, Protein standard in kilodaltons (kDa). b Semi-quantitative calculation of soluble fraction of the MZ0009 fusion proteins. Error bars show variation in two independent experiments. c Chitinolytic activity, presented as normalized fluorescence intensities, towards three synthetic 4-methylumbelliferone-labelled (4MU) chitin analogs in the cleared lysates containing MZ0009 fused to fusion proteins. Background activity from expression of ‘empty’ vectors is indicated with a dashed baseline. A.U., arbitrary units. Error bars show variation in two replicates in one representative experiment