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alpha,beta-unsaturated aldehydes accelerate oxymyoglobin oxidation.
C Faustman1, D C Liebler, T D McClure
1Department of Animal Science, University of Connecticut, Storrs 06269-4040, USA. cfaustma@ansc1.cag.uconn.edu
Journal of Agricultural and Food Chemistry
|December 20, 1999
Summary
Lipid oxidation products, specifically alpha,beta-unsaturated aldehydes, accelerate oxymyoglobin (OxyMb) oxidation. This occurs through covalent attachment, forming metmyoglobin (MetMb) and impacting myoglobin
Area of Science:
- Biochemistry
- Food Chemistry
Background:
- Oxymyoglobin (OxyMb) is crucial for oxygen transport and storage.
- Lipid oxidation products, such as aldehydes, can interact with proteins.
- Understanding these interactions is vital for food quality and biological systems.
Purpose of the Study:
- To investigate how lipid oxidation products, specifically aldehydes, enhance oxymyoglobin oxidation.
- To determine the chemical basis for the observed acceleration of OxyMb oxidation.
Main Methods:
- Incubation of OxyMb with various aldehydes at physiological conditions (37°C, pH 7.4).
- Quantification of metmyoglobin (MetMb) formation.
- Analysis of covalent adduction using electrospray ionization mass spectrometry (ESI-MS).
Main Results:
- Alpha,beta-unsaturated aldehydes caused greater MetMb formation than saturated aldehydes.
- Increasing aldehyde chain length enhanced MetMb formation.
- ESI-MS confirmed covalent attachment of 4-hydroxynonenal (HNE) to OxyMb, forming adducts.
- A prooxidant effect of HNE was observed at pH 7.4 but not pH 5.6 due to rapid OxyMb autoxidation at lower pH.
Conclusions:
- Alpha,beta-unsaturated aldehydes accelerate OxyMb oxidation.
- Covalent attachment of aldehydes to OxyMb is a key mechanism for this acceleration.
- The pH-dependent prooxidant effect of HNE is influenced by OxyMb autoxidation rates.