Purification of lactate dehydrogenase isoenzyme-5 from human liver.
Clinical chemistry
confidence
Key findings
Method for purifying human liver lactate dehydrogenase isoenzyme-5; no clinical or biological endpoints reported.
View source on PubMed (PMID 7449128) ↗
- Sample size
- Not reported
- Population
- Human liver (in vitro purification)
- Dosing
- Not applicable
- Duration
- Not reported
- Route
- Not applicable
- Blinding
- not_reported
- Controls
- none
- Drug class
- coenzyme
Full abstract
We present a method for preparing human liver lactate dehydrogenase (L-lactate:NAD+ oxidoreductase; EC 1.1.1.27) isoenzyme-5 by sequential ion-exchange chromatography, general-ligand (AMP analog) affinity chromatography, and preparative isoelectric focusing. The yield ws 40%, with a 493-fold purification. The final specific activity was 458 kU per gram of protein. The preparation contained less than 0.2% of lactate dehydrogenase isoenzyme-4, was homogeneous by agarose gel electrophoresis and also by polyacrylamide gel electrophoresis at pH 8.9 and 6.9, and showed one major protein band (containing all the enzyme activity) and one minor anodic contaminant (containing no enzyme activity) by analytical isoelectric focusing. The enzyme had a mean pI value of 9.59 (SD 0.04) (n = 5) at 5 degrees C. By comparison, the pI value of a preparation of rabbit lactate dehydrogenase-5 was 9.16 (5 degrees C).