Digestive Alkaline Proteases from Zosterisessor ophiocephalus, Raja clavata, and Scorpaena scrofa: Characteristics and Application in Chitin Extraction

Table 2

Stability of alkaline proteases in the presence of various surfactants and oxidizing agents.

Surfactants/oxidizing agents	Concentration (%)	Residual activity (%)
		Goby	Scorpionfish	Thornback ray
None	0	100	100	100
Triton X-100	5 (v/v)	100	107	117
Tween 20	5	82	109	115
Tween 80	5	90	107	100
SDS	0.1 (w/v)	40	73.5	13
	0.5	33	44	0
	1	14	16	0
Sodium perborate	0.2	92.3	106	88
	1	66	100	70

Enzyme preparations were incubated with different surfactants and oxidizing agents for 1 hour at 30°C and the remaining activity was measured under standard conditions. The activity is expressed as a percentage of the activity level in the absence of additives.