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P1512

Sigma-Aldrich

Thermolysin from Geobacillus stearothermophilus

Type X, lyophilized powder, 30-350 units/mg protein (E1%/280)

Synonym(s):

Protease from Geobacillus stearothermophilus, Thermophilic-bacterial protease

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About This Item

CAS Number:
Enzyme Commission number:
EC Number:
MDL number:
UNSPSC Code:
12352204
eCl@ss:
32160410
NACRES:
NA.54

biological source

Geobacillus stearothermophilus

type

Type X

form

lyophilized powder

specific activity

30-350 units/mg protein (E1%/280)

mol wt

34.6 kDa by amino acid sequence

purified by

crystallization

shipped in

wet ice

storage temp.

−20°C

General description

Thermolysin is a protease that has specificity different from other proteases available for sequence investigations.

Application

A thermostable (thermophilic) extracellular metalloendopeptidase containing four calcium ions. Cofactors are zinc and calcium. Hydrolyzes protein bonds on the N-terminal side of hydrophobic amino acid residues. The pH optimum is 8.0 and the optimal temperature for activity is 70 °C. Considerably stable from pH 5 to 9.5. Thermolysin has a low cleavage specificity, therefore, it produces a number of short fragments that are suitable for sequencing. Preferential cleavage: X-cleavage-Y-Z where X=any amino acid; Y=Leu, Phe, Ile, Val, Met, Ala and Z is any amino acid other than Pro. Cleavage N-terminal to Leu is preferred over cleavage of N-terminal to Phe which is preferred over the others. Often used to do limited proteolysis for peptide mapping and studies of protein structure and conformational changes.
Thermolysin has been shown to have a prosequeence that acts as an intramolecular chaperone in vivo. It has also been used in a study to investigate the effects of sodium chloride on thermal stability and catalytic activity.
Thermolysin is also commonly used for the commercial synthesis of N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester, the precursor for the artificial sweetener aspartame.

Quality

Contains many extraneous enzymes.

Unit Definition

One unit will hydrolyze casein to produce color equivalent to 1.0 μmole (181 μg) of tyrosine per min at pH 7.5 at 37 °C (color by Folin-Ciocalteu reagent).

Physical form

lyophilized powder containing calcium and sodium acetate buffer salts

Preparation Note

The pH optimum is 8.0 and the optimal temperature for activity is 70 °C. Considerably stable from pH 5 to 9.5. Thermolysin has a low cleavage specificity, therefore, it produces a number of short fragments that are suitable for sequencing. Preferential cleavage: X-cleavage-Y-Z where X=any amino acid; Y=Leu, Phe, Ile, Val, Met, Ala and Z is any amino acid other than Pro. Cleavage N-terminal to Leu is preferred over cleavage of N-terminal to Phe which is preferred over the others.

Pictograms

Health hazard

Signal Word

Danger

Hazard Statements

Hazard Classifications

Resp. Sens. 1

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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K Inouye et al.
Biochimica et biophysica acta, 1388(1), 209-214 (1998-10-17)
Thermolysin, a thermophilic metalloproteinase, is markedly activated in the presence of high concentrations (1-5 M) of neutral salts. The activity increases in an exponential fashion with increasing salt concentration, and is enhanced 13-15 times with 4 M NaCl at pH
The use of thermolysin in amino acid sequence determination.
R P Ambler et al.
The Biochemical journal, 108(5), 893-895 (1968-08-01)
M Miyanaga et al.
Biotechnology and bioengineering, 46(6), 631-635 (1995-06-20)
N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester, a precursor of the synthetic sweetener, aspartame, was synthesized from N-(benzyloxycarbonyl)-L-aspartic acid and L-phenylalanine methyl ester with an immobilized thermolysin (EC 3.4.24.4) in the mixed organic solvent system of tert-amyl alcohol and ethyl acetate. A mixed solvent
Balbir K Chaal et al.
Methods in molecular biology (Clifton, N.J.), 390, 207-217 (2007-10-24)
All the algae with chlorophyll (Chl) c (haptophytes, cryptophytes, and heterokonts such as diatoms) acquired their chloroplasts by secondary endosymbiosis, where a nonphotosynthetic eukaryote host engulfed (or was invaded by) a red alga. This resulted in chloroplasts with four bounding
Haley Marshall et al.
Acta crystallographica. Section D, Biological crystallography, 68(Pt 1), 69-81 (2011-12-24)
Both crystallization and cryoprotection are often bottlenecks for high-resolution X-ray structure determination of macromolecules. Methylamine osmolytes are known stabilizers of protein structure. One such osmolyte, trimethylamine N-oxide (TMAO), has seen occasional use as an additive to improve macromolecular crystal quality

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