Literature summary extracted from

Chaari, F.; Bhiri, F.; Blibech, M.; Maktouf, S.; Ellouz-Chaabouni, S.; Ellouz-Ghorbel, R.
Potential application of two thermostable lichenases from a newly isolated Bacillus licheniformis UEB CF: purification and characterization (2012), Process Biochem., 47, 509-516.

No PubMed abstract available

Inhibitors

EC Number	Inhibitors	Comment	Organism	Structure
3.2.1.73	Co2+	inhibits isozyme EG1 by 35%, and isozyme EG2 also slightly, at 2.5 mM	Bacillus licheniformis
3.2.1.73	Cu2+	inhibits isozyme EG1 by 28%, but slightly activates isozyme EG2 at 2.5 mM	Bacillus licheniformis
3.2.1.73	Fe2+	inhibits isozyme EG1 by 50% at 2.5 mM	Bacillus licheniformis
3.2.1.73	H2O2	at 0.5% w/v hydrogen peroxide, isozymes EG1 and EG2 retain 82.8% and 90.28% of their activities, respectively. At 1% w/v hydrogen peroxide, isozyme EG2 retains 60% activity, while isozyme EG1 is completely inhibited	Bacillus licheniformis
3.2.1.73	Hg2+	complete inhibition of both isozymes at 2.5 mM	Bacillus licheniformis
3.2.1.73	additional information	the isozymes are highly stable in the presence of non-ionic surfactants such as Tween 80 and Triton X-100	Bacillus licheniformis
3.2.1.73	SDS	the strong anionic surfactant at 0.1% and 0.5% causes a moderate inhibition of 27.5% and 30.7% of isozyme EG2 activity. Isozyme EG1 is highly stable against SDS and retains 100% of its activity in the presence of 0.1% and 0.5% SDS	Bacillus licheniformis
3.2.1.73	sodium perborate	isozymes EG1 and EG2 retain 58% and 66.8% of their activities after 1 h of incubation at 40°C in the presence of 0.2% w/v sodium perborate, respectively	Bacillus licheniformis
3.2.1.73	Zn2+	78% inhibition of isozyme EG1, poor inhibition of isozyme EG2	Bacillus licheniformis

KM Value [mM]

EC Number	KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
3.2.1.73	additional information	-	additional information	2.1 mg/ml for isozyme EG1 and 1.8 mg/ml for isozyme EG2 with lichenan at pH 5.0, 50°C	Bacillus licheniformis

Metals/Ions

EC Number	Metals/Ions	Comment	Organism	Structure
3.2.1.73	Ca2+	enhances the isozyme EG1 and EG2 activities by 32.7% and 12%, respectively, at 2.5 mM. Ca2+ enhances the substrate binding affinity of the enzyme and stabilize the conformation of the catalytic site	Bacillus licheniformis
3.2.1.73	Cu2+	inhibits isozyme EG1 by 35%, but slightly activates isozyme EG2 at 2.5 mM	Bacillus licheniformis
3.2.1.73	Fe2+	slightly activates isozyme EG2 at 2.5 mM	Bacillus licheniformis
3.2.1.73	additional information	poor effects on both isozymes by Mg2+ and EDTA at 2.5 mM	Bacillus licheniformis

Molecular Weight [Da]

EC Number	Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
3.2.1.73	30000	-	1 * 30000, isozyme EG1, SDS-PAGE, 1 * 50000, isozyme EG2, SDS-PAGE	Bacillus licheniformis
3.2.1.73	50000	-	1 * 30000, isozyme EG1, SDS-PAGE, 1 * 50000, isozyme EG2, SDS-PAGE	Bacillus licheniformis
3.2.1.73	55000	-	isozyme EG2, native PAGE	Bacillus licheniformis

Organism

EC Number	Organism	UniProt	Comment	Textmining
3.2.1.73	Bacillus licheniformis	-	isozymes EG1 and EG2	-
3.2.1.73	Bacillus licheniformis UEB CF	-	isozymes EG1 and EG2	-

Purification (Commentary)

EC Number	Purification (Comment)	Organism
3.2.1.73	native extracellular isozymes EG1 and EG2 0.24fold and 11.6fold, respectively, from cell-free culture supernatant by dialysis and concentration with PEG 400, followed by anion exchange chromatography and gel filtration, both isozymes to homogeneity	Bacillus licheniformis

Specific Activity [micromol/min/mg]

EC Number	Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
3.2.1.73	15.6	-	isozyme EG1, pH 5.0, 50°C, substrate lichenan	Bacillus licheniformis
3.2.1.73	767	-	isozyme EG2, pH 5.0, 50°C, substrate lichenan	Bacillus licheniformis

Substrates and Products (Substrate)

EC Number	Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
3.2.1.73	barley beta-glucan + H2O	-	Bacillus licheniformis	3-O-beta-cellobiosyl-D-glucose + 3-O-beta-cellotriosyl-D-glucose	oligosaccharides, mainly trisaccharide and tetrasaccharide	?
3.2.1.73	barley beta-glucan + H2O	-	Bacillus licheniformis UEB CF	3-O-beta-cellobiosyl-D-glucose + 3-O-beta-cellotriosyl-D-glucose	oligosaccharides, mainly trisaccharide and tetrasaccharide	?
3.2.1.73	lichenan + H2O	-	Bacillus licheniformis	3-O-beta-cellobiosyl-D-glucose + 3-O-beta-cellotriosyl-D-glucose	oligosaccharides, mainly trisaccharide and tetrasaccharide	?
3.2.1.73	lichenan + H2O	-	Bacillus licheniformis UEB CF	3-O-beta-cellobiosyl-D-glucose + 3-O-beta-cellotriosyl-D-glucose	oligosaccharides, mainly trisaccharide and tetrasaccharide	?
3.2.1.73	additional information	no activity with carboxymethyl cellulose and laminarin, isozymes EG1 and EG2 exhibit no activity for pure beta-1,3 bond and for pure beta-1,4 glucan forms	Bacillus licheniformis	?	-	?
3.2.1.73	additional information	no activity with carboxymethyl cellulose and laminarin, isozymes EG1 and EG2 exhibit no activity for pure beta-1,3 bond and for pure beta-1,4 glucan forms	Bacillus licheniformis UEB CF	?	-	?

Subunits

EC Number	Subunits	Comment	Organism
3.2.1.73	monomer	1 * 30000, isozyme EG1, SDS-PAGE, 1 * 50000, isozyme EG2, SDS-PAGE	Bacillus licheniformis

Synonyms

EC Number	Synonyms	Comment	Organism
3.2.1.73	EG1	-	Bacillus licheniformis
3.2.1.73	Lichenase	-	Bacillus licheniformis

Temperature Optimum [°C]

EC Number	Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
3.2.1.73	60	-	isozyme EG2	Bacillus licheniformis
3.2.1.73	70	-	isozyme EG1	Bacillus licheniformis

Temperature Stability [°C]

EC Number	Temperature Stability Minimum [°C]	Temperature Stability Maximum [°C]	Comment	Organism
3.2.1.73	40	50	purified isozymes EG1 and EG2, retaining over 90% activity after 1 h	Bacillus licheniformis
3.2.1.73	60	-	purified isozymes EG1 and EG2, half-lives are 55 min and 5 h, respectively	Bacillus licheniformis
3.2.1.73	70	-	purified isozymes EG1 and EG2, half-lives are 10 min and 52 min, respectively	Bacillus licheniformis

Turnover Number [1/s]

EC Number	Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
3.2.1.73	60	-	lichenan	isozyme EG1, pH 5.0, 50°C	Bacillus licheniformis
3.2.1.73	708.3	-	lichenan	isozyme EG1, pH 5.0, 50°C	Bacillus licheniformis

pH Optimum

EC Number	pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
3.2.1.73	5	-	isozyme EG1	Bacillus licheniformis
3.2.1.73	7	-	isozyme EG2	Bacillus licheniformis

pH Range

EC Number	pH Minimum	pH Maximum	Comment	Organism
3.2.1.73	4	10	isozyme EG1, more than 80% of maximal activity within pH range pH 4.0-7.0, 50% at pH 10.0. Isozyme Eg2 shows over 70% of maximal activity at pH 4.0-10.0	Bacillus licheniformis

pH Stability

EC Number	pH Stability	pH Stability Maximum	Comment	Organism
3.2.1.73	4	10	purified isozymes EG1 and EG2, retaining over 90% activity after 48 h, after 72 h isozyme EG1 loses 30% and isozyme EG2 15% activity	Bacillus licheniformis

General Information

EC Number	General Information	Comment	Organism
3.2.1.73	additional information	N-terminal amino acid sequences of isozymes EG1 and EG2 are GAAPIKKGTTKLN and DINGGGATLPQK, respectively	Bacillus licheniformis

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Release 2023.1 (January 2023)