Claim · model-written summary
Splitting of protohemin from holoperoxidase coincides with a decrease in enzymatic activity at high temperatures.
- Taxon
- Japanese-radish
Raphanus sativus var. longipinnatuse0 - Treatment
- at high temperaturese2
- Compound
- protohemine2
- Outcome
- activitye2
- Direction
- degreasee2
Not reportedMaterialGeneOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thermal denaturation of Japanese-radish peroxidase”
e2“The splitting process of protohemin from holoperoxidase as followed by the change in the absorption spectrum at high temperatures coincided with the degrease in the activity”
Title
Thermal Denaturation and Regeneration of Japanese-radish Peroxidase12
Yoshiyuki TAMURA; Yuhei MORITA The Journal of Biochemistry 1975. doi:10.1093/oxfordjournals.jbchem.a130941
Other claims from this paper (12)
- Observation Inactivation of the peroxidase occurs above 60 degrees and involves three processes.
- Observation Regeneration of peroxidase on cooling to room temperature is essentially reversible at neutral pH.
- Observation Regeneration of peroxidase on cooling is irreversible at pH 5 and pH 9.
- Mechanism Irreversibility at acidic pH is mainly due to an irreversible change in the conformation of the apoenzyme.
- Mechanism Irreversibility at alkaline pH is largely attributable to the modification of protohemin.
- Intervention effect Heat-treated apoperoxidase shows a 20% increase in total protein fluorescence quantum yield relative to untreated apoenzyme.
- Observation Heat-treated apoperoxidase shows a denaturation blueshift with negative maxima at 287 and 294 nm.
- Observation Apoperoxidase is more resistant to heat denaturation than the holoenzyme.
- Observation Modification or degradation of protohemin in heated enzyme is greater at alkaline pH than at acidic pH.
- Observation Heat treatment shifts the alpha-band maxima of the pyridine-ferrohemochrome spectrum slightly to shorter wavelength.
- Observation Heat treatment yields a new heme derivative other than protohemin.
- Observation The modified product is probably (2(4)-vinyl-4(2)-hydroxyethyldeuterohemin).