Rat Mammary Arginase: Isolation and Characterization
| Autor: | M.R. Grigor, Christopher P. Jenkinson |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
chemistry.chemical_classification
Gel electrophoresis Kidney Arginase Immunoprecipitation Endocrinology Diabetes and Metabolism Protein subunit Hydrogen-Ion Concentration Protein degradation Biology Biochemistry Isozyme Rats Molecular Weight Mammary Glands Animal Enzyme medicine.anatomical_structure chemistry medicine Animals Female Rabbits Rats Wistar |
| Zdroj: | Biochemical Medicine and Metabolic Biology. 51:156-165 |
| ISSN: | 0885-4505 |
| DOI: | 10.1006/bmmb.1994.1020 |
| Popis: | The extrahepatic arginase, AII, from rat mammary gland was isolated and its properties investigated and compared with those of the hepatic arginase, AI. Mammary arginase activity increased 300% at mid-lactation, an increase unaccompanied by an increase in liver arginase activity. Mammary gland contained two isozymes, separable by ion exchange chromatography. The major form, AII, was purified 103-fold and antisera were raised against it. A 1300-fold purification was achieved temporarily but the enzyme was unstable. Arginase AII was kinetically similar to AI: both had pH optima of 10 and Kms for L-arginine of 12-14 mM. Arginase AII differed from AI in having a near-neutral pI and a slightly larger subunit size (39,800 Da compared to 38,900 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)). Solution immunoprecipitation studies revealed that virtually all of the arginase present in liver was type AI, whereas kidney and mammary gland contained both isozymes. Western immunoblotting showed that the amount of immunoreactive mammary arginase AII protein increased at mid-lactation in parallel with the increase in activity. This suggests that the elevated arginase activity is due to de novo protein synthesis and/or reduced protein degradation, rather than activation of arginase. |
| Databáze: | OpenAIRE |
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