
The enzyme is useful for the determination of creatinine and creatine in clinical analysis.
由来 | recombinant E. coli |
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系统名称 | Creatine amidinohydrolase |
EC编号 | 3.5.3.3 |
反应式 | Creatine + H2O →→→ Sarcosine + Urea |
The enzyme is useful for the determination of creatinine and creatine in clinical analysis.
由来 | recombinant E. coli |
---|---|
系统名称 | Creatine amidinohydrolase |
EC编号 | 3.5.3.3 |
反应式 | Creatine + H2O →→→ Sarcosine + Urea |
Appearance | white to light yellow lyophilizate | |
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Activity | ≧9 U/mg | |
Stabilizer | sucrose | |
Storage condition | below -20℃ |
Molecular weight | ca. 80 kDa (gel filtration) |
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Structure | 2 subunits of 46 kDa (SDS-PAGE) |
Michaelis constant | 1.3×10-2M (creatine) |
pH Optimum | 7.0–9.0 (Fig. 1) |
pH Stability | 5.0–11.0 (Fig. 2) |
Optimum temperature | 40℃ (Fig. 3) |
Thermal stability | below 45℃ (Fig. 4) |
Stability (liquid form) | stable at 37℃ for at least two weeks (Fig. 5) |
Stability (powder form) | stable at 30℃ for at least one month (Fig. 6) |
Inhibitors | Hg2+ |
The enzyme is useful for the determination of creatinine and creatine in clinical analysis.
The appearance of urea is measured spectrophotometrically at 435 nm.
One unit (U) is defined as the amount of enzyme which produces 1 μmol of urea per min at 37℃ and pH 7.7 under the conditions described below.
Sample: dissolve the lyophilized enzyme to a volume activity of 1.4–2.8 U/ml with ice-cold enzyme dilution buffer (Reagent D) immediately before measurement.
0.1 ml | Potassium phosphate buffer | (Reagent A) |
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0.8 ml | Creatine solution | (Reagent B) |
Activity can be calculated by using the following formula:
Suzuki, M, Medical Technology, 7, 945–950 (1979).
Suzuki, M. and Yoshida, M. (1984)
A new enzymatic determination of serum creatine
Clinica Chimica Acta, 140, 289–294.
Suzuki, M. and Yoshida, M. (1984)
A new enzymatic serum creatinine measurement based on an endogenous creatine-eliminating system
Clinica Chimica Acta, 143, 147–155.