Abstract
A quantitative assay has been developed to measure holocarboxylase synthetase activity in cellular extracts. This assay was based on measuring the incorporation of [3H]biotin of high specific activity (4.3 Ci/mmol) into purified rat liver apopyruvate carboxylase. With this assay, holocarboxylase synthetase in 3T3-L1 mouse fibroblasts has been monitored. During the differentiation of this cell from a fibroblast to an adipocyte, holocarboxylase synthetase activity was found to increase threefold, while pyruvate carboxylase activity rose 20-fold. The results suggest a possible relationship between the activity of the holocarboxylase synthetase and the level of the biotin-dependent carboxylases within the mammalian cell. Utilizing digitonin fractionation, the intracellular distribution of this enzyme has also been examined. In the 3T3-L1 cell, the large majority (approximately 70%) of the total holocarboxylase synthetase activity was found in the cytosolic compartment.
Original language | English |
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Pages (from-to) | 237-247 |
Number of pages | 11 |
Journal | Archives of Biochemistry and Biophysics |
Volume | 225 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1983 Aug |
Externally published | Yes |
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology