Identification of a New Serine Alkaline Peptidase from the Moderately Halophilic Virgibacillus natechei sp. nov., Strain FarD^T and its Application as Bioadditive for Peptide Synthesis and Laundry Detergent Formulations

Table 4

Substrate specificity profile of rSAPV enzyme.

Substrate	Concentration	Absorbance (nm)^a	Relative protease activity (%)^b
Natural protein
Casein	25 g/L	600	100 ± 2.5
Albumin	25 g/L	600	80 ± 1.8
Gelatin	25 g/L	600	42 ± 1.2
Ovalbumin	25 g/L	600	16 ± 0.4
Keratin	25 g/L	600	24 ± 0.9
Modified protein
Azo-casein	20 g/L	440	100 ± 2.5
Albumin azure	20 g/L	440	64 ± 1.6
Keratin azure	20 g/L	440	18 ± 1.4
Collagen type I or II	10 g/L	440	0 ± 0.0
Ester
ATEE	10 mM	253	100 ± 2.5
BTEE	10 mM	253	89 ± 2.4
BAEE	10 mM	253	0 ± 0.0
BCEE	10 mM	253	0 ± 0.0
TAME	10 mM	253	0 ± 0.0
Synthetic peptide (pNA)
P4-P3-P2-P1-P′1
Suc-F-pNA	5 mM	410	52 ± 1.7
Benz-Y-pNA	5 mM	410	0 ± 0.0
Met-pNA	5 mM	410	0 ± 0.0
Ac-L-pNA	5 mM	410	0 ± 0.0
Pro-pNA	5 mM	410	0 ± 0.0
Ac-A-pNA	5 mM	410	0 ± 0.0
Benz-R-pNA	5 mM	410	63 ± 1.9
Suc-Y-L-V-pNA	5 mM	410	0 ± 0.0
Suc-A-A-A-pNA	5 mM	410	0 ± 0.0
Suc-A-A-V-pNA	5 mM	410	21 ± 0.1
Suc-A-A-F-pNA	5 mM	410	35 ± 0.8
Benz-F-V-R-pNA	5 mM	410	0 ± 0.0
Suc-F-A-A-F-pNA	5 mM	410	100 ± 2.5
Suc-A-A-P-F-pNA	5 mM	410	87 ± 2
Suc-A-A-V-A-pNA	5 mM	410	75 ± 1.8
Suc-A-A-P-M-pNA	5 mM	410	62 ± 1.4
Suc-A-A-P-L-pNA	5 mM	410	38 ± 0.4
Suc-L-L-V-Y-pNA	5 mM	410	52 ± 0.9
Ac-Y-V-A-D-pNA	5 mM	410	0 ± 0.0

^aValues represent the means of three replicates, and ± standard errors are reported. ^bThe activity of each substrate was determined by measuring absorbance at specified wave lengths according to the relative method reported elsewhere [32]. BTEE: N-benzol-L-tyrosine ethyl ester; ATEE: N-acetyl-L-tyrosine ethyl ester monohydrate; BAEE: N-benzol-L-arginine ethyl ester; BCEE: S-benzyl-L-cysteine ethyl ester hydrochloride; TAME: Nα-p-tosyl-L-arginine methyl ester hydrochloride. N-succinyl-L-Phe-p-nitroanilide; N-benzoyl-L-Tyr-p-nitroanilide; N-acetyl-L-Leu-p-nitroanilide; L-Met-p-nitroanilide; L-Pro-p-nitroanilide trifluoroacetate salt; N-acetyl-L-Ala-p-nitroanilide; L-Val-p-nitroanilide hydrochloride; N-benzoyl-L-Arg-p-nitroanilide; N-succinyl-L-Tyr-L-Leu-L-Val-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Phe-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Val-p-nitroanilide; N- benzoyl-L-Phe-L-Val-L-Arg-p-nitroanilide; N-succinyl-L-Phe-L-Ala-L-Ala-L-Phe-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Val-L-Ala-p-nitroanilide; N-succinyl-L-Leu-L-Leu-L-Val-L-Tyr-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Pro-L-Met-p-nitroanilide; N-succinyl-L-Ala-L-Ala-L-Pro-L-Leu-p-nitroanilide; N-acetyl-L-Tyr-L-Val-L-Ala-L-Asp-p-nitroanilide.