Effect of high hydrostatic pressure (HHP) on structure and activity of phytoferritin

High hydrostatic pressure (HHP) has drawn considerable attention because of its potential application in food industry. Ferritin, an iron storage protein, is widely distributed in food made from legume seeds, which is highly stable due to its shell-like structure. Therefore, it is of special interest to know whether or not high HHP treatment has effect on this protein. In this study, the structure and activity of soybean seed ferritin (SSF) were examined by circular dichroism spectrum (CD), UV–VIS and fluorescence spectrophotometry in conjunction with stopped-flow light scattering upon treatment with HHP at 400 MPa for 10 min. Results revealed that such treatment has little effect on the primary and secondary structure of SSF, but pronouncedly altered its tertiary and quaternary structure. As a result, the protein aggregation property and iron release activity were dramatically changed, while its activity of iron oxidative deposition was kept unchanged.

► HHP treatment had little effect on the primary and secondary structure of SSF.
► HHP greatly changed its tertiary and quaternary structure around Trp residues.
► Protein aggregation properties were markedly altered after HHP treated.
► The rate of iron release from holo-SSF became much slower.
► The catalytic activity of SSF remained unchanged.