ACACIA CAVEN (MOL.) MOLINA POLLEN PROTEASES. APPLICATION TO THE PEPTIDE SYNTHESIS AND TO LAUNDRY DETERGENTS - Biochemical Engineering - page 299

130

b )

40º C

120

110

25º C

100

90

80

50º C

70

60º C

0 20 40 60 80 100

Time (min)

Figure 2. a) Effect of the temperature on the proteolytic activity of Acacia caven CE in 0.1M Tris-HCl
buffer pH 8, after 5 min of incubation. b) Thermostability of Acacia caven CE in 0.1 M Tris-HCl buffer
pH 8. BAPNA was used as substrate.

On the other hand, Acacia caven CE demonstrated to be active over a broad pH range and
more than 40 % of its maximum activity was exhibited between pH 7.5 and 10. One of the
most important parameters for selecting proteases for both laundry detergents and catalyst of
peptide synthesis is the optimum pH. The desired pH of a detergent solution in which
proteases work should be approximately the same as the optimum pH for the enzyme [32].
Since the pH of laundry detergents is commonly alkaline protease and other enzymes
currently used in detergent compositions should be alkaline in nature with a high optimum pH
[33]. Besides, peptide synthesis reactions should be carried out at high pH in order to
maximize the concentration of the unionized amine form of the nucleophile. These properties
were displayed by Acacia caven proteases.

120 120 120

0.1% (v/v)
0.4% (v/v)
1% (v/v)

25º C 40º C 60º C

100 100 100

80 80 80

60 60 60

40 40

40

20 20 20

0 0 0

Triton X100 Tween 20 Tween 80 EFA Arlatone Triton X100 Tween 20 Tween 80 EFA Arlatone Triton X100 Tween 20 Tween 80 EFA Arlatone

Figure 3. Effect of different concentration of some ionic and non-ionic surfactants (0.1, 0.4 and 1%
(v/v)) on the proteolytic activity of Acacia caven CE, after 1 h at 25, 40 and 60º C.