BsAra51B (BsAra5A)

Ex-Ara0135

(EC.3.2.1.55)exo-α-arabinofuranosidase

CAZy Family: GH51

PROPERTIES

1.ELECTROPHORETIC PURITY

-Single band on SDS-gel electrophoresis (MW ~58 kDa)

Figure 1. Electrophoresis analysis ofBsAra51B. M, molecular weight marker (PageRuler Prestained Protein Ladder, Thermo Scientific); lane 1, culture lysate before IPTG induction; lane 2, culture lysate after IPTG induction; lane 3,BsAra51Bpurified from Ni sepharose fastflow column.

2.SPECIFIC ACTIVITY

2.51 U/mg protein (on pNP-α-Araf) at pH 7.0 and 37°C.

One Unit of pNP-α-Araf activity is defined as the amount of enzyme required to release 1 μmol of p-nitrophenyl per minute from pNP-α-Araf (5 mM) in phosphate buffer (20 mM) pH 7.0.

3.RELATIVE RATES OF HYDROLYSIS OF SUBSTRATES

Table 1. Relative activity ofBsAra51Bon different substrates^a.

^aReactions were performed with 5 mM substrate, pH 7.0, at 37°C for 5 min.

^bAbsorption caused by released p-nitrophenol was measured at 405 nm. The relative activity on pNPαAraf was taken as 100%.

^cThe data are reported as means±standard errors from the mean for three independent experiments.

Table2.Catalytic activity of BsAra51B

nd, Although enzyme activity was present it was not possible to measure the individual kinetic constants.

4.PHYSICOCHEMICAL PROPERTIES

pH Optima: 8.0

Temperature Optima: 50°C

5.STORAGE CONDITIONS

The enzyme should be stored at -20°C. For assay, this enzyme should be diluted in phosphate buffer (20 mM) pH 7.0. Swirl to mix the enzyme immediately prior to use.

6. REFERENCES

[1] Inacio J M, Correia I L, de Sa-Nogueira I. Two distinct arabinofuranosidases contribute to arabino-oligosaccharide degradation in Bacillus subtilis[J]. Microbiology, 2008, 154(9): 2719-2729.