D-Lactate Dehydrogenase (D-LDH), Grade I
from Lactobacillus delbrückii, lyophilizate
For further processing only.
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D-Lactate Dehydrogenase (D-LDH), Grade I material number and pack size: Material Number Pack Size 11291416103 custom fill
- Dehydrogenase that catalyzes the interconversion of D(-)-lactate to pyruvate.
- Use D-Lactate Dehydrogenase (D-LDH), Grade I, in a variety of diagnostic tests, e.g., in the determination of alanine aminotransferases, lactate or pyruvate. Used for the removal of pyruvate in determinations working with NADH (i.e., triglycerides, lipase, aldolase, aspartate aminotransferases, glutamate dehydrogenase).
Nomenclature: D-lactate:NAD+ oxidoreductase
Michaelis constants (Tris maleate buffer, pH 8.0, +25°C):
D-lactate: 0.7 x 10-1 mol/L (NAD, 2 mmol/L)
Pyruvate: 1.2 x 10-3 mol/L (NADH, 0.1 mmol/L)
NADH: 7.1 x 10-5 mol/L (pyruvate, 20 mmol/L)
pH optimum: 7.0 (see figure)
Temperature dependence: See figure
pH stability: 4.0-10.0 (see figure)
Thermal stability: Up to +50°C (see figure)
Specificity: Lactate dehydrogenase is specific for D(-)-lactate, L(+)-lactate does not react.
Remark: Lactate dehydrogenase, Grade I is especially suited for liquid stable applications with extended shelf life requirements. Appearance: White to yellowish lyophilizate
Solubility: Clear to yellowish solution in water (c=10 mg/mL)
pH value (c=10 mg/mL in water): 6.0-7.0
Activity (+25°C, pyruvate): ≥180 U/mg lyophilizate
Specific activity: ≥450 U/mg protein
Protein (Biuret) : No limit, 0.3-0.8 mg/mg lyophilizate
Contaminants (expressed as percentage of D-Lactate Dehydrogenase activity):
Alcohol dehydrogenase: ≤0.01
Malate dehydrogenase: ≤0.1
''NADH oxidase'': ≤0.0005
Succinate dehydrogenase: ≤0.01
NH4: ≤0.01 μmol/KU
Na (flame photometric): ≤0.5 μmol/KU
K (flame photometric): ≤0.007 μmol/KU
Stability: At +2 to +8°C within specification range for 12 months. Store dry.