Purification et detection de plusieurs formes moleculaires de l'histidine decarboxylase de la muqueuse gastrique de rat
| Autor: | Alain Savany, L. Cronenberger |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Aromatic L-amino acid decarboxylase
Chromatography biology Isoelectric focusing Size-exclusion chromatography General Medicine Histidine decarboxylase Enzyme assay chemistry.chemical_compound Isoelectric point chemistry Biochemistry biology.protein Pyridoxal phosphate Polyacrylamide gel electrophoresis |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Enzymology. 526:247-258 |
| ISSN: | 0005-2744 |
| DOI: | 10.1016/0005-2744(78)90309-1 |
| Popis: | A specific histidine decarboxylase from rat gastric mucosa has been obtained at high purity and good yield (purification about 600-fold). The purification procedure included double (NH4)2SO4 fractionation, ion-exchange chromatography, preparative isoelectric focusing in a granulated gel and gel filtration. Only the specific histidine enzyme was obtained by that procedure; DOPA decarboxylase, a non-specific enzyme, was absent in our final preparation. Each step of the purification was visualized by polyacrylamide gel electrophoresis and analytical isoelectric focusing. The purified enzyme was apparently homogeneous by criteria of electrophoresis and gel filtration and has a molecular weight of 94 000. Several protein bands appeared after isoelectric focusing and the enzyme activity was localized in 3 distinct peaks. The gastric enzyme consists of 3 active forms which could be distinguished by their isoelectric points: 5.4, 5.75 and 6. Molecular weights estimated by SDS polyacrylamide gel electrophoresis were 97 000, 93 000 and 90 000, and no subunits were observed. Pyridoxal phosphate was required as a coenzyme and resolution of the holoenzyme agreed with a portion of the coenzyme tightly bound to the apo-enzyme. The purified enzyme was stable at low ionic strength, near neutral pH; concentrated reducing agents inhibit the enzyme. |
| Databáze: | OpenAIRE |
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