Table 2 Effect of chemical agents on keratinase activity. Values are the mean of three replicates ± standard deviation. 100% of activity corresponds to those displayed by the enzyme without the presence of any chemical

 None

100

 PMSF

1 mM

103.1 ± 5.8

 Iodoacetate

10 mM

95.5 ± 6.3

 EDTA

5 mM

33.5 ± 1.8

 1,10-Phenanthroline

1 mM

83.3 ± 3.4

 Pepstatin A

100 μg/ml

108.1 ± 7.3

 Mg²⁺

1 mM

111.8 ± 6.0

 Zn²⁺

1 mM

107.6 ± 1.8

 Ca²⁺

1 mM

104.6 ± 1.2

 Hg²⁺

1 mM

95.9 ± 3.6

 Co⁺²

1 mM

97.3 ± 0.6

 Mn⁺²

1 mM

112.8 ± 4.3

 Na⁺

1 mM

90.3 ± 0.6

 K⁺

1 mM

89.9 ± 1.2

 Triton X-100

0.5 % (v/v)

97.7 ± 2.7

 Tween 20

0.5 % (v/v)

98.5 ± 2.0

 SDS

0.5 % (v/v)

75.9 ± 3.4

 H₂O₂

1 % (w/v)

100.9 ± 2.6

2 % (w/v)

98.9 ± 2.5

3 % (w/v)

79.8 ± 5.5

 Sodium perborate

0.2 % (w/v)

86.6 ± 5.1

0.5 % (w/v)

80.3 ± 5.1

 DMSO

1 % (v/v)

100 ± 0.6

 Ethanol

1 % (v/v)

100 ± 0.3

 Methanol

1 % (v/v)

100 ± 0.6

 Isopropanol

1 % (v/v)

100 ± 1.0