BtMan92B

Ex-Man0083

(EC.3.2.1)exo-α-1,4-Mannosidase

CAZy Family: GH92

PROPERTIES

1.ELECTROPHORETIC PURITY

-Single band on SDS-gel electrophoresis (MW ~74 kDa)

Figure 1. Electrophoresis analysis of BtMan92B. 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, BtMan92B purified from Ni sepharose fastflow column.

2.SPECIFIC ACTIVITY

3.RELATIVE RATES OF HYDROLYSIS OF SUBSTRATES

Table 1. Relative activity of BtMan92B on different substrates^a.

^aReactions were performed with 5 mM substrate, pH 7.0, at 37°C for 10 min.

^bAbsorption caused by released p-nitrophenol was measured at 405 nm.

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

Figure.2 Amannose release indicated the enzyme wasactive against the substrate (+), while no release of the sugar is indicative of no activity (–). The score for each protein is based on the HPlC signal for mannose after 16 h incubations with 1 µM of enzyme: HPlC signals > 500 nanocoulomb (nc), +++; 200–500 nc, ++; <200 nc, +;cNA: no activity was detected.

4.PHYSICOCHEMICAL PROPERTIES

pH Optima: 7.0

Temperature Optima: 37°C

5.STORAGE CONDITIONS

The enzyme should be stored at -20°C. For assay, this enzyme should be diluted in phosphate buffer (20 mM) pH7.0. Swirl to mix the enzyme immediately prior to use.

6. REFERENCES

[1]Zhu Y, Suits M D L, Thompson A J, et al. Mechanistic insights into a Ca2+-dependent family of α-mannosidases in a human gut symbiont[J]. Nature chemical biology, 2010, 6(2): 125-132.