Propionyl carboxylase purified from bovine liver mitochondria catalyzes the carboxylation of 992 micromoles of propionyl-CoA per hour per milligram of protein. Relative carboxylation rates for acetyl-, propionyl-, butyryl-, and valeryl-CoA remain constant during purification. The carboxylase is inhibited by PCMB, N-ethylmaleimide, and iodoacetamide; and the inhibition by PCMB can be almost completely reversed by GSH. The K<sub>m</sub> values for acetyl-CoA, propionyl-CoA, butyryl-CoA, valeryh-CoA, propionyl pantetheine, ATP, and HCOj were determined. The K<sub>m</sub> values for the aeyl-CoA derivatives are approximately the same while there is a 200-fold difference between the V<sub>m</sub> values for propionyl-CoA and valeryl-CoA. Coenzyme A and valeryl-CoA, but not propionyl pantetheine were found to be competitive inhibitors of propionyl carboxylase.
The apparent equilibrium constant for the enzymatic propionyl-CoA carboxylation reaction at pH 8.15 and 37°c is 8.1 x 10<sup>-3</sup> and the Δ F°<sub>310</sub> calculated from this constant is 2970 calories per mole. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/41960 |
| Date | 07 April 2010 |
| Creators | Feng, Marjorie Jan-yung |
| Contributors | Biochemistry and Nutrition, Lane, M. Daniel, Engel, R. W., King, Kendall W., Vingiello, Frank A. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 30 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 22676039, LD5655.V855_1962.F463.pdf |
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