Description
In enzymology, a creatinase (EC 3.5.3.3) is an enzyme that catalyzes the chemical reaction: creatine + H2O ↔sarcosine + urea. Thus, the two substrates of this enzyme are creatine and H2O, whereas its two products are sarcosine and urea. The native enzyme was shown to be made up of two subunit monomers via SDS-polyacrylamide gel electrophoresis. Creatinase has been found to be most active at pH 8 and is most stable between ph 6-8 for 24 hrs. at 37 degrees. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amidines. This enzyme participates in arginine and proline metabolism.
Abbr
Creatinase, Native (Microorganism)
Applications
This enzyme is useful for enzymatic determination of creatinine when coupled with creatine amidinohydrolase, sarcosine dehydrogenase or sarcosine oxidase and formaldehyde dehydrogenase in clinical analysis.
Appearance
White amorphous powder, lyophilized
Enzyme Commission Number
EC 3.5.3.3
Activity
GradeⅡ 4.0 U/mg-solid or more
Contaminants
NADH oxidase < 5.0×10⁻²%; Catalase < 2.0%
Molecular Weight
approx. 67 kDa (by gel filtration)
Isoelectric point
4.5±0.1
pH Stability
pH 4.0-10.0 (25°C, 20hr)
Michaelis Constant
4.5×10－3 M (Creatine)
Structure
2 subunits per mol of enzyme
Optimum temperature
40－50°C
Thermal stability
below 70°C (pH 7.5, 30min)
Stability
Stable at -20°C for at least one year
Inhibitors
Hg⁺⁺, Cu⁺⁺, Ag⁺, SH reagent (NEM), PCMB
Synonyms
Creatine amidohydrolase; Creatinase; EC 3.5.3.3
