Figure 2.

Plot of OD₄₁₀ vs. depolymerase concentration for samples of succinoglycan treated for 24 hr with either ExoK (squares) or ExsH (triangles) and then subjected to the Lever-reducing end assay. We tested a series of fivefold dilutions of the two proteins, starting at a concentration of 20 μg/ml. Substrates: 0.38 mg/ml native succinoglycan (A), 0.27 mg/ml neutral/heat-treated succinoglycan (B), and 0.20 mg/ml acid/heat-treated succinoglycan (C). Arrows indicate OD₄₁₀ for untreated succinoglycan (*) or succinoglycan depolymerized completely to octasaccharide by succinoglycan depolymerase of Cytophaga arvensicola (∗∗). Each data point represents the average of three samples (SD < 10%).