Table 1.
Biochemical Analysis of Peroxisome Purity
| HPR
|
NADP-Dependent GAPDH
|
Fumarase
|
||||||
|---|---|---|---|---|---|---|---|---|
| Activity (nkat) | Percentage of CE | Activity (nkat) | Percentage of CE | Contamination (%) | Activity (nkat) | Percentage of CE | Contamination (%) | |
| Crude extract | 1240 ± 70 | 100 | 1500 ± 500 | 100 | 167 ± 35 | 100 | ||
| Leaf peroxisome fraction LP-P1 | 89.5 ± 27.5 | 7.2 | 0.39 ± 0.14 | 0.026 | 0.36 | 0.56 ± 0.32 | 0.33 | 4.6 |
| Leaf peroxisome fraction LP-P2 | 45.8 ± 17.5 | 3.7 | 0.065 ± 0.029 | 0.0043 | 0.12 | 0.10 ± 0.04 | 0.062 | 1.7 |
Peroxisome purity was determined on the basis of marker enzyme activities specific for leaf peroxisomes (HPR), chloroplasts (NADP-dependent GAPDH), and mitochondria (fumarase). The protein content of the leaf peroxisomal fraction LP-P2 was 115 ± 29 μg, resulting in a specific HPR activity of 293 ± 76 nkat/mg protein and a yield of 1.9 ± 0.5 μg protein/g fresh weight. The content of chlorophyll (thylakoids) was below the limits of detection in both leaf peroxisomal fractions LP-P1 and P2 (data not shown) (n = 5). CE, crude extract.