L-Lactate Dehydrogenase (L-LDH)
ROCHE/LLDH-RO
Synonym: L-LDH; L-Lactate Dehydrogenase; l-lactate
Product Type: Chemical
| form | suspension |
| manufacturer/tradename | Roche |
| packaging | pkg of 10 mL (10127884001 [100 mg]) |
| pkg of 2 mL (10127230001 [10 mg]) | |
| pkg of 5 mL (10127876001 [25 mg]) | |
| Quality Level | 100  |
| shipped in | wet ice |
| specific activity | ~550 units/mg protein (at 25 °C (1,100 U/mg at 37 °C) with pyruvate as the substrate.) |
| storage temp. | 2-8°C |
| Analysis Note: | Absorbance:The purified enzyme from beef heart has an absorbance of 14.9 (10 mg/ml, 280 nm). |
| Application: | Reduction of α-ketoacids to α-hydroxycarboxylic acids, or reverse reaction. |
| General description: | L-lactate:NAD+ oxidoreductase. L-lactate dehydrogenase catalyzes the reversible reduction of pyruvate to L-lactate. |
| Other Notes: | For life science research only. Not for use in diagnostic procedures. |
| Physical form: | Suspension in 3.2 M ammonium sulfate solution, pH approximately 7 |
| Preparation Note: | Activator: 2-amino-2-methyl-1-propan |
| Sequence: | LDH is a tetramer (MW = approx. 140,000 D, rabbit muscle or pig heart LDH). In mammals, there are two types of LDH subunits, M and H, with similar molecular weight (subunit MW ≈ 36,500 D) but differing amino acid composition. Therefore, 5 electrophoretically distinguishable LDH isoenzymes, LDH-1 through LDH-5, of differing subunit composition, are found in mammals. The molecular weight of all LDH isoenzymes is approximately the same. – LDH-1 (H4), LDH-2 (H3M): predominant components of heart LDH – LDH-3 (H2M2): principal component of LDH from lymphatic tissue – LDH-4 (HM3), LDH-5 (M4): predominate in skeletal muscle or liver LDH Note: The M subunit of LDH used to be designated the A subunit; the H subunit was the B subunit. Under the old designation, LDH-1 isoenzyme was LDH-B4. |
| Specificity: | L()-Lactate dehydrogenase (LDH) is specific for L()-lactate (relative rate = 100). It does not react with D(-)-lactate.LDH will also slowly oxidize glyoxylate (oxoacetate), glycerate and 3-halogen derivatives of L-lactate (rate with each, ≤ 1); 3-phosphoglycerate does not react.LDH will reduce pyruvate (2-oxopropanate; relative rate = 100) and other 2-oxoacids (e.g., 2-oxobutyrate), with rates decreasing rapidly with increasing chain length of the acid. Heart LDH reacts with 2-oxobutyrate at a greater rate than does skeletal muscle LDH.LDH will also oxidize 2,4-diketoacids (relative rate = 10). The enzyme is realtively specific for NAD(H) (relative rate = 100); NADP(H) is utilized much less efficiently (relative rate < 1). Representative Kms for (hog) skeletal muscle LDH (pH 7.5) are lactate, 8.3 mM; pyruvate, 0.12 mM; NAD, 0.10 mM; NADH, 0.012 mM.Representative Kms for (pig) heart LDH (pH 7.5) are lactate, 3.3 mM; pyruvate, 0.15 mM; NAD, 0.07 mM;NADH, 0.011 mM. In general, the concentration of pyruvate (reduction reaction) or of L-lactate (oxidation reaction) necessary to obtain a maximal rate with LDH is lower for preparations from heart tissue than for the preparations from skeletal muscle. |
| Unit Definition: | One unit (U) lactate dehydrogenase will reduce 1 mol of pyruvate to L-lactate in 1 minute at +25 °C and pH 7.0. Note: For preparations H and I, the activity is defined at +30 °C, pH 7.8. The above assay consumes 1 mol of NADH per mol of pyruvate reduced. Unit Conversion: For the reduction reaction, pyruvate as substrate: 1 U (+25 °C) 1.5 U (+37 °C) [hog muscle LDH in glycerol]. 1 U (+25 °C) 1.8 U (+37 °C) [hog muscle LDH in amm onium sulfate]. 1 U (+25 °C) 1.1 U (+30 °C) 2.0 U (+37 °C) [rabbit muscle LDH]. 1 U (+25 °C) 1.4 U(+30 °C) 2.5 U (+37 °C) [pig heart LDH]. 1 U (+25 °C) 2.5 U (+37 °C) [beef heart LDH]. |
| RIDADR | NONH for all modes of transport |
| WGK Germany | WGK 1 |
| Flash Point(F) | does not flash |
| Flash Point(C) | does not flash |
| activity | specific activity: ~550 units/mg protein (at 25 °C (1,100 U/mg at 37 °C) with pyruvate as the substrate.) |
| Storage Temp. | 2-8°C |
| Enzyme Commission (EC) Number | 1.1.1.27 ( BRENDA  | IUBMB ) |
| UNSPSC | 12352200 |