Full text loading...
Abstract
SUMMARY: Homogenates from Polytomella caeca were fractionated by differential centrifugation. All the mitochondria (located by measurement of cytochrome c oxidase) and most of the peroxisomes (located by measurement of catalase) sedimented at 105 g min. Most of the NADPH-cytochrome c oxidoreductase, IDPase and acid p-nitrophenyl phosphatase were still present in the supernatant. This supernatant also contained a cytochrome b, cytochromes P-450 and P-416. Zonal centrifugation indicated that catalase and cytochrome oxidase were entirely sedimentable at 6 x 106 g min and that NADPH-and antimycin A-insensitive NADH-cytochrome c oxidoreductases were not mitochondrial. Peroxisomes (ρ = 1.25) were separated from mitochondria (ρ = 1.20) by both rate and isopycnic-zonal centrifugation. Two zones of acid ρ‐nitrophenyl phosphatase activity were detected, one at ρ = 1.15 and the other at ρ= 1.21, but no other acid hydrolases were found. Separation, of polysomes and various microsomal enzymes (IDPase, acid p-nitrophenyl phosphatase, NADH-and NADPH-cytochrome c oxidoreductases) was also achieved.
- Accepted:
- Published Online: