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1
Supplementary Materials 1
2
3
Muropeptide rescue in Bacillus subtilis involves sequential hydrolysis by 4
exo-β-N-acetylglucosaminidase and N-acetylmuramyl-L-alanine amidase 5
Silke Litzinger1, Amanda Duckworth1, Katja Nitzsche1, Christian Risinger2, 6
Valentin Wittman2 and Christoph Mayer1* 7
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9
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Synthesis of 4-Methylumbelliferyl-2-amino-2-deoxyglucopyranoside 5 1
2
OAcO
OAc
AcOTrocHN
OAcO
OAc
AcOTrocHN
O OO
O
CCl3
NH
O OHO
+
DCM
BF3 Et2O
OAcO
OAc
AcOH2N
O OOOHO
OH
HOH2N
O OOZn, AcOH NaOMe
MeOH87%
60%
98%
1 2 3
4 5 3 4
Scheme 1. Synthesis of 4-Methylumbelliferyl-2-amino-2-deoxyglucopyranoside 5 5
6
4-Methylumbelliferyl glycoside 4 (3, 5, 6) was synthesized by an improved procedure 7
(Scheme 1). Troc protected trichloroacetimidate 1 (2) and 4-Methylumbelliferone 2 were 8
reacted under BF3 catalysis. The obtained glycoside 3 was then deprotected in two steps to 9
yield the desired compound 5. 10
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Experimental Section 12 13 General Methods: Cation exchange resin Amberlite IR-120 (H+) was pre-washed with dry 14
MeOH before use. Analytical thin layer chromatography (TLC) was performed on Merck 15
Silica Gel 60 F245 aluminium sheets (thickness 0.2 mm). Compound spots were visualized by 16
quenching of fluorescence and/or by charring after treatment with cerium reagent (5 g 17
molybdatophosphoric acid, 2.5 g ceric sulphate tetrahydrate, 25 mL sulphuric acid and 225 18
mL water), ethanolic ninhydrin (3% v/v), and ethanolic sulphuric acid (15 % v/v), 19
respectively. Flash column chromatography (FC) was performed on Macherey-Nagel Silica 20
Gel 60 (0.04-0.063 mm; 230-400 mesh ASTM). 1H and 13C NMR spectra were recorded at 21
293 K on Bruker AC 250, Bruker Avance III 400 or Bruker Avance DRX 600 spectrometers. 22
Resonance assignments were made by the aid of COSY, HSQC and HMBC when necessary. 23 1H chemical shifts are referenced to residual protic solvent (CDCl3, δH = 7.26 ppm; CD3OD, 24
δH = 3.31 ppm; DMSO-d6, δH = 2.50 ppm ). 13C chemical shifts are referenced to the solvent 25
Table S1. Identity of BsNagZ with a partially purified GlcNAc`ase of B. subtilis reported 1
earlier (1, 4) 2
3
BsNagZ
(this study) Partially purified GlcNAc`ase (1, 4)
Occurrence produced towards the end of growth (i.e. late log phase, stationary phase)
Compartmentalisation
released into medium
mainly found in a sedimentable form (about 70 % in the 30,000 x g sediment)
with increasing culture age more particulate material (after 15h: about 90 % in the 30,000 x g sediment)
NaCl extraction 80 - 90 % released from cells and from sedimented material with 3 M NaCl at 30,000 x g
pH optimum 5.8-6.2 5.9-6.0
most stable at 4.0- 8.0 8.5
pI 9.37 (calculated) “seems to be 3.8”
MW a70-75 kDa 75 kDa
KM; specific activity
(pNP-β-GlcNAc)
b171.6 µM
8.33 µmol/min mg
150 µM;
14.50 µmol/min mg
KM; specific activity
(4-β-Mu-GlcNAc)
109.6 µM;
5.39 µmol/min mg
110 µM;
5.26 µmol/min mg
KM; Specific activity
(GlcNAc-MurNAc) n.d.
18 µM;
32.6 µmol/min mg
4-Mu-β-GlcN no substrate n.d.
4-Mu-β-GalNAc no substrate no substrate
a the calculated molecular weight of the cloned protein including His6-tagis 71.3 kDa 4 b kinetic parameters were determined at pH 5.8 in Clark and Lubs buffer (0.1M KH2PO4/0.1M 5 NaOH). n.d., not determined. 6
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1 2
Figure S1. Purity of recombinant BsNagZ and BsAmiE. Sodium dodecyl sulfate-3
polyacrylamid gel electrophoresis (SDS-PAGE) of elution fractions (numbers) of the Ni-4
chelate affinity chromatography of BsNagZ (A) and BsAmiE (B). BsNagZ shows a molecular 5
weight of about 70-75 kDa (calculated 71.3 kDa) and BsAmiE of about 40-45 kDa (calculated 6
47.9 kDa). The molecular weight marker is indicated (M). 7
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1 Figure S2. pH activity profile of NagZ. The kcat versus pH plot revealed a bell-shaped curve 2
with a pH-optimum in the range of 5.8 to 6.2 with 4-methylumbelliferyl-β-N-acetyl-D-3
glucosaminide (4-Mu-β-GlcNAc) as the substrate. The buffers were: 0.1 M citric acid/0.2 M 4
disodium phosphate buffer (McIlvaine) ranging from pH 4.0 to 8.0 (); 0.2M sodium acetate-5
acetic acid buffer ranging from 4.0 to 5.6 () and Clark and Lubs solution (0.1 M 6
KH2PO4/0.1 M NaOH) in the range of pH 5.8 to 8.0 (). 7
8
References 9 10 1. Berkeley, R. C., S. J. Brewer, J. M. Ortiz, and J. B. Gillespie. 1973. An exo-β-N-11
2. Dullenkopf, W., J. C. Castro-Palomino, L. Manzoni, and R. R. Schmidt. 1996. N-14 trichloroethoxycarbonyl-glucosamine derivatives as glycosyl donors. Carbohydr. Res. 15 296:135-47. 16
3. Macauley, M. S., K. A. Stubbs, and D. J. Vocadlo. 2005. O-GlcNAcase catalyzes 17 cleavage of thioglycosides without general acid catalysis. J. Am. Chem. Soc. 18 127:17202-3. 19
4. Ortiz, J. M., J. B. Gillespie, and R. C. Berkeley. 1972. An exo-β-N-20 acetylglucosaminidase from Bacillus subtilis B; extraction and purification. Biochim. 21 Biophys. Acta 289:174-86. 22
5. Roeser, K. R., and G. Legler. 1981. Role of sugar hydroxyl groups in glycoside 23 hydrolysis. Cleavage mechanism of deoxyglucosides and related substrates by β-24 glucosidase A3 from Aspergillus wentii. Biochim. Biophys. Acta 657:321-33. 25
6. Whitworth, G. E., M. S. Macauley, K. A. Stubbs, R. J. Dennis, E. J. Taylor, G. J. 26 Davies, I. R. Greig, and D. J. Vocadlo. 2007. Analysis of PUGNAc and NAG-27 thiazoline as transition state analogues for human O-GlcNAcase: mechanistic and 28 structural insights into inhibitor selectivity and transition state poise. J. Am. Chem. 29 Soc. 129:635-44. 30