The presence of heat-stable conformers of ovalbumin affects properties of thermally formed aggregates
article
The aim of this work was to study the effect of the formation of more heat-stable conformers of chicken egg ovalbumin during incubation at basic pH (9.9) and elevated temperature (55°C) on the protein aggregation properties at neutral pH. Native ovalbumin (N-OVA) is converted on the hours time-scale into more heat-stable forms denoted I- (intermediate) and S-OVA, that have denaturation temperatures 4.8 and 8.4°C, respectively, higher than that of N-OVA. The conversions most likely proceed via I-OVA, but direct conversion of N-OVA into S-OVA with slower kinetics can not be excluded. It is demonstrated that both I- and S-OVA have similar denaturation characteristics to N-OVA, except that higher temperatures are required for denaturation. The presence of even small contributions of I-OVA does, however, reduce the Stokes radius of the aggregates formed upon heat treatment of the material at 90°C about 2-fold. This affects the gel network formation considerably. Since many (commercial) preparations of ovalbumin contain varying contributions of the more heat-stable forms mentioned, proper characterization or standardization of the isolation procedure of the material is essential to control or predict the industrial application of this protein.
Chemicals/CAS: ovalbumin, 77466-29-6; Ovalbumin, 9006-59-1
Chemicals/CAS: ovalbumin, 77466-29-6; Ovalbumin, 9006-59-1
Topics
Food technologyAggregationOvalbuminProtein denaturationStokes radiusTurbidityOvalbuminChemical reaction kineticsHeat treatmentPHPriority journalProtein aggregationProtein analysisProtein denaturationProtein stabilityThermostabilityTurbidityAnimalsCalorimetry, Differential ScanningChickensHeatKineticsOvalbuminProtein ConformationTime FactorsGallus gallus
TNO Identifier
237473
ISSN
02692139
Source
Protein Engineering, 16(12), pp. 1035-1040.
Pages
1035-1040
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