BgtA | Biochem 3

Abbreviation

HmBgtA

Source

Helicobacter mustelae

Activity

Transfer GalNAc from UDP-GalNAc to Gal of H-antigen via an a1,3-linkage

Expression

Purification

Expression system: pET28a with C-terminal His6-tag , E. coli BL21(DE3)

Induction condition: 0. 2 mM IPTG, 16 °C, 20 h, 200 rpm, Luria LB broth

Purification:

1) Suspend cells collected from 1 L medium in ice-cold 40 mL Buffer-A

2) Disrupt cells by a CF1 cell disruptor (Constant Systems), 20 kPsi, 4 °C

3) Centrifuge at 12000 x g, 4 °C, 30 min

4) Load supernatant to a 10 mL gravity column filled with 2 mL Ni-NTA resin (pre-equilibrated)

5) Wash with 50 mL Buffer-A, then 50 mM Buffer-B, finally elute with 10 mL Buffer-C.

6) Concentrate into 2.5 mL and change buffer to Buffer D using a PD-10 column.

7) Store at 4 °C for up to 6 months, store at -80 °C for up to 1 year (avoid repeated freeze)

Buffers: A: 20 mM Tris-HCl (pH 8.0), 300 mM NaCl, 10 mM imidazole;

B: A + 15 mM imidazole; C: A + 250 mM imidazole.

D: 50 mM Tris-HCl (pH 8.0), 100 mM NaCl, 20 % Glycerol

Optimal Condition

37 °C

7.5

MnCl2

50 mM Tris-HCl (pH 7.5), 22 mM donor, 20 mM acceptor, 20 mM MnCl2, incubate at 37 °C for 1 h to overnight.

Temperature:

pH:

Metal ion:

Example condition:

UDP-GalNAc and derivative

All types of H-antigen

Donor:

Acceptor:

Kinetics:

Substrate Specificity

Yi W., Shen J., et al. Bacterial homologue of human blood group A transferase. J Am Chem Soc, 2008, 130, 14420.
Chaubard, J., Krishnamurthy C., et al. Chemoenzymatic Probes for Detecting and Imaging Fucose-α(1-2)-galactose Glycan Biomarkers. J Am Chem Soc, 2012, 134, 4489.

References