Claim · model-written summary
Regeneration of peroxidase on cooling is irreversible at pH 5 and pH 9.
- Taxon
- Japanese-radish
Raphanus sativus var. longipinnatuse0 - Treatment
- cooling to room temperaturee3
- Outcome
- regeneration of peroxidasee3
- Qualifier
- at pH 5 and pH 9 these processes were irreversiblee3
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingDirectionValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thermal denaturation of Japanese-radish peroxidase”
e3“The regeneration of peroxidase on cooling to room temperature was essentially reversible at neutral pH, while at pH 5 and pH 9 these processes were irreversible”
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.
- Association Splitting of protohemin from holoperoxidase coincides with a decrease in enzymatic activity at high temperatures.
- Observation Regeneration of peroxidase on cooling to room temperature is essentially reversible at neutral pH.
- 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).