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Table 1 Specific activity (U/mg) against colloidal chitin and synthetic substrates of Cv Chi45

From: Expression and efficient secretion of a functional chitinase from Chromobacterium violaceum in Escherichia coli

Substrate

CvChi45

S. griseuschitinase

Colloidal chitin*

22,260.5

20,368.0

p-nitrophenyl-N-acetyl-β-D-glucosamine (pNP-GlcNAc)**

ND

ND

p-nitrophenyl-β-D-N,N’-diacetylchitobiose [pNP-(GlcNAc)2]**

32,320.0

10,370.0

p-nitrophenyl-β-D-N,N’,N”-triacetylchitotriose [pNP-(GlcNAc)3]**

31,560.0

9,120.0

  1. The specific activity (U/mg) of the purified chitinase was measured using colloidal chitin and synthetic substrates as described in the Methods section. A chitinase from Streptomyces griseus (Sigma) was included for comparison.
  2. * For assays using colloidal chitin as the substrate (0.5% final concentration), one unit was defined as the amount of enzyme that released 1 nmol of GlcNAc/mg/h at 37°C.
  3. ** For assays using synthetic substrates, one unit was defined as the amount of enzyme that released 1 nmol of 4-nitrophenol/mg/h at 37°C; the substrates were assayed at final concentrations of 2.9 mM (pNP-GlcNAc), 1.8 mM [pNP-(GlcNAc)2], and 1.3 mM [pNP-(GlcNAc)3]; ND: not detected.