Studies on some enzymatic properties of mitochondrial propionyl carboxylase

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_m values for acetyl-CoA, propionyl-CoA, butyryl-CoA, valeryh-CoA, propionyl pantetheine, ATP, and HCOj were determined. The K_m values for the aeyl-CoA derivatives are approximately the same while there is a 200-fold difference between the V_m 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^-3 and the Δ F°₃₁₀ calculated from this constant is 2970 calories per mole.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biochemistry and Nutrition

Department dc:contributor.department

Biochemistry and Nutrition

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1962

Author dc:creator

• Feng, Marjorie Jan-yung

Chair dc:contributor.committeechair

• Lane, M. Daniel

Committee members dc:contributor.committeemember

• Engel, R. W.
• King, Kendall W.
• Vingiello, Frank A.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-04072010-020058

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/41960