Date of Graduation

2000

Document Type

Thesis

Degree Type

MS

Committee Chair

Kenneth P. Blemings

Abstract

To understand tissue participation in lysine oxidation, chicken lysine α-ketoglutarate reductase (LKR) activity and lysine oxidation (LOX) were measured in vitro. LKR activity was measured using a spectrophotometer and LOX was measured by collection of 14CO2 from [U-14C] L-lysine. LKR and LOX were measured in homogenates prepared from liver, kidney, pancreas, heart, brain, lungs, spleen, muscle, and intestine. LKR activities were 1000-fold LOX. LKR activity was highest in liver and intestine each approximately 63 µmoles/(hr*g tissue). Activity in other tissues was significantly greater than zero except for muscle. Muscle, liver, and intestine contributed about 70%, 15% and 6.5% respectively of the total oxidative capacity. The Km and Vmax for LKR were 6.96 ± 1.87 mM and 29.4 ± 2.94 µmoles/(hr*g liver) respectively. A significant (p< 0.05) increase in LKR activity was found in lysine adequate (1.1, 2.1, or 3.1%) diets compared to a lysine deficient diet (0.69%).

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