Skip to main content

Table 1 Kinetic parameters of WT and H208F mutant

From: Engineering broad-spectrum digestion of polyuronides from an exolytic polysaccharide lyase

  WT H208F
k CAT (s−1) K M (mM) k CAT/K M k CAT (s−1) K M (mM) k CAT/K M
Alginate 34.8 0.67 52.2 14.6 1.35 10.8
PolyManA 62.2 0.41 151.8 21.3 0.41 51.5
Poly-GulA 34.6 5.99 5.8 1.4 2.22 0.7
Poly-MG 22.2 0.57 38.7 2.0 0.98 2.1
Poly-GlcA 0.4 1.40 0.3 6.1 0.57 10.6
  1. WT and H208F mutant were added to 10 different solutions containing 7.8–4000 µg/mL substrate in 20 mM sodium phosphate buffer at pH 8.5 for alginate-based polysaccharides, and pH 8 for poly-GlcA. Enzymatic activity was monitored by absorbance at 235 nm, and all reactions were performed in triplicate. Turnover rate (k CAT) was calculated using an extinction coefficient of 6150 M−1 cm−1 for the unsaturated product [11, 12]. K M values are based upon an effective molecular weight of 176 for the monosaccharide unit, the smallest product formed by Smlt2602 during catalysis [12, 52]