|
type |
Journal Article |
authors |
Siow, Y. L.; Dakshinamurti, K. |
title |
Purification of dopa decarboxylase from bovine striatum |
journal |
Mol Cell Biochem |
Activity |
4.1.1.28 |
ui |
90326084 |
year |
(1990) |
volume |
94 |
number |
2 |
pages |
121-31. |
| |
keywords |
5-Hydroxytryptophan/metabolism |
abstract |
Pyridoxal phosphate-dependent DOPA decarboxylase has been purified from bovine striatum to a specific activity of 1.6 U/mg protein. After ammonium sulfate precipitation (30-60%) it was purified by DEAE- Sephacel, Sephacryl S-200, and TSK Phenyl 5 PW chromatography. The purified enzyme showed a single silver straining band with polyacrylamide gel electrophoresis under both denaturing and non- denaturing conditions. The bovine striatal DOPA decarboxylase is a dimer (subunit Mr = 56,000 by SDS-PAGE) with a native Mr of 106,000 as judged by chromatography on Sephacryl S-200 and by sedimentation analysis. Similar to the DOPA decarboxylase purified from non-CNS tissues, the bovine striatal enzyme requires free sulfhydryl groups for activity, is strongly inhibited by heavy metal ions, and can decarboxylate 5-hydroxytryptophan as well. It should be noted, however, that the final enzyme preparation is enriched in DOPA decarboxylase activity. The distribution of the DOPA decarboxylase and 5-HTP decarboxylase activities also varies among several bovine brain regions. In addition, heat treatment of the enzyme preparation inactivated the two decarboxylation activities at different rates. |
last changed |
2002/11/12 16:17 |
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