Claim · model-written summary
PPO activity correlated with a 48 kDa polypeptide.
- Taxon
- Spinach
Spinacia oleraceat0 - Gene
- 48 kDa polypeptidee0
- Outcome
- PPO activitye0
Not reportedMaterialCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorSettingDirectionValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Spinach”
e0“PPO activity was correlated with a 48 kDa polypeptide”
Title
Yelena G. Sheptovitsky; Gary W. Brudvig Biochemistry 1996. doi:10.1021/bi9613842
Other claims from this paper (15)
- Observation PSII membranes showed catalase and PPO activities.
- Intervention effect Mild heating of PSII membranes released most catalase and PPO activities.
- Intervention effect Mild heating activated PPO sevenfold.
- Intervention effect Mild heating did not release significant amounts of either activity from thylakoid membranes.
- Mechanism Both enzymes were inferred to bind the luminal thylakoid surface.
- Association Catalase activity correlated with a 63 kDa polypeptide.
- Mechanism PSII-associated catalase was unstable in solution, probably through irreversible aggregation.
- Observation PSII-associated catalase was characterized as a previously unidentified luminal membrane-bound heme enzyme.
- Intervention effect 3-amino-1,2,4-triazole irreversibly inhibited residual catalase activity after heating.
- Intervention effect 3-amino-1,2,4-triazole did not inhibit oxygen evolution.
- Mechanism The oxygen-evolving center contributed little, if any, dark catalase activity.
- Observation The 48 and 72 kDa polypeptides shared an N-terminal sequence identical to a known 64 kDa protein.
- Observation Most 72 kDa polypeptide converted into the 48 kDa polypeptide during heating and manipulation.
- Mechanism The 72 kDa polypeptide was interpreted as a latent precursor of active PPO.
- Observation Heat-released PPO appeared identical to an enzyme previously isolated from spinach thylakoids.