Effect of sodium tripolyphosphate on the interaction and aggregation behavior of ovalbumin-lysozyme complex. (1st August 2021) - Jin, Haobo
Highlights: Disulfide bonds dominated the interaction between ovalbumin and lysozyme. The complex of ovalbumin and lysozyme had maximum turbidity at pH 7.0. Heat treatment made the structure of complex more stretched and disordered. Phosphorylation weakened the interaction between ovalbumin and lysozyme. Abstract: The mechanism by which sodium tripolyphosphate affected the aggregation behavior of ovalbumin-lysozyme complexes was investigated in this work. The highest stability coefficients were detected for natural ovalbumin and lysozyme at pH 9.0 and pH 5.0, with values of 0.981 and 0.931, respectively. The turbidity of the phosphorylated ovalbumin-lysozyme complexes was 1.71-fold to the natural complexes at pH 7.0. This result was related to the fact that the phosphorylated sample had a lower isoelectric point. Besides, both intermolecular forces and SDS-PAGE analysis indicated that the disulfide bond was the most important interaction in the complex. Circular dichroism analysis showed that phosphorylation weakened the unfolding and stretching of the structure caused by heat treatment. Moreover, transmission electron microscopy pictures confirmed that the network structure of phosphorylated ovalbumin-lysozyme complex was broader than natural protein. This study provides information for further understanding the effect of phosphorylation on protein aggregation behavior.