Table 3.
Relative specific activities of mAAT and cysteine S-conjugate β-lyase in fractions obtained from rat kidney mitochondria
| Fraction | mAAT (mU/mg)a (A) |
Cysteine S-conjugate β- lyase (mU/mg)b (B) |
A/B |
|---|---|---|---|
| Mitochondria (unfractionated)c | 1316 | 5.4 | 244 |
| Mitochondria (high-Mr fraction)d | 51 | 0.23 | 222 |
| Mitochondria (low-Mr fraction)d | 2190 | 7.8 | 281 |
a
The reaction mixture contained 6 mM α-ketoglutarate, 10 mM L-aspartate and 100 mM potassium phosphate buffer (pH 7.4); 37°C. The rate of oxaloacetate formation was measured. One unit = one μmol/min.
b
The reaction mixture contained 10 mM TFEC, 0.1 mM α-ketoglutarate, and 100 mM potassium phosphate buffer (pH 7.4); 37°C. Pyruvate formation was determined.
c
Kidney mitochondria were prepared as described by Zhang et al. (2006) and disrupted by sonication.
d
Fractionated as noted in Table 2.