6533b855fe1ef96bd12aff0c
RESEARCH PRODUCT
Hemocyanin conformational changes associated with SDS-induced phenol oxidase activation.
Elmar JaenickeJacqueline NairnChristian MeestersDorothea NilliusSharon BairdSharon M. KellyNicholas C. PriceHeinz Deckersubject
Copper proteinmedicine.medical_treatmentBiophysicschemistry.chemical_elementBiochemistryOxygenProtein Structure SecondaryAnalytical ChemistryScorpionsEnzyme activatorCatalytic DomainHorseshoe CrabsmedicineAnimalsMolecular Biologychemistry.chemical_classificationOxidase testMonophenol MonooxygenaseSodium Dodecyl SulfateHemocyaninIsothermal titration calorimetrySpidersProtein tertiary structureProtein Structure TertiaryEnzyme ActivationEnzymechemistryBiochemistryHemocyaninsCopperdescription
The enzymatic activity of phenoloxidase is assayed routinely in the presence of SDS. Similar assay conditions elicit phenoloxidase activity in another type 3 copper protein, namely hemocyanin, which normally functions as an oxygen carrier. The nature of the conformational changes induced in type 3 copper proteins by the denaturant SDS is unknown. This comparative study demonstrates that arthropod hemocyanins can be converted from being an oxygen carrier to a form which exhibits phenoloxidase activity by incubation with SDS, with accompanying changes in secondary and tertiary structure. Structural characterisation, using various biophysical methods, suggests that the micellar form of SDS is required to induce optimal conformational transitions in the protein which may result in opening a channel to the di-copper centre allowing bulky phenolic substrates access to the catalytic site.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-05-23 | Biochimica et biophysica acta |