3:00 PM - 3:15 PM
[2Lp-01] Structural analysis of human serum albumin and ovalbumin at a foam surface by hydrogen/deuterium exchange mass spectrometry
Keywords:Protein, Foam, Mass spectrometry
[Objective] Proteins have surfactant activity and are used as foaming agents in the food industry. Structural changes of proteins occur at the air-water interface, and the structure of proteins at the interface is closely related to the foaming properties. In this study, to elucidate the protein structure at the foam surface, we established a novel structural analysis method using hydrogen/deuterium exchange mass spectrometry (HDX-MS) and analyzed human serum albumin (HSA) and ovalbumin (OVA).
[Methods] The hydrogen/deuterium (HD) exchange in the foam and solution states were monitored by mass spectrometry and compared between the two states. The structural change of the proteins and the adsorption sites to the interface were identified based on the difference in the HD exchange rate.
[Results] For HSA, the N-terminus and a loop (E492-T506) were identified as adsorption sites, and structural changes were widely observed throughout the structure. Analysis by circular dichroism spectroscopy and HDX-MS after defoaming suggested that the structural changes at the air-water interface were reversible (Enomoto et al. J Agric Food Chem. 2024). For OVA, three peptides (Y107-Y118, I157-A172, and F189-M212) were considered as adsorption sites. Since the adsorption sites of both HSA and OVA contained hydrophobic amino acids and were flexible sites such as loops, both structural flexibility and hydrophobicity could be important factors for the adsorption to the air-liquid interface.
[Methods] The hydrogen/deuterium (HD) exchange in the foam and solution states were monitored by mass spectrometry and compared between the two states. The structural change of the proteins and the adsorption sites to the interface were identified based on the difference in the HD exchange rate.
[Results] For HSA, the N-terminus and a loop (E492-T506) were identified as adsorption sites, and structural changes were widely observed throughout the structure. Analysis by circular dichroism spectroscopy and HDX-MS after defoaming suggested that the structural changes at the air-water interface were reversible (Enomoto et al. J Agric Food Chem. 2024). For OVA, three peptides (Y107-Y118, I157-A172, and F189-M212) were considered as adsorption sites. Since the adsorption sites of both HSA and OVA contained hydrophobic amino acids and were flexible sites such as loops, both structural flexibility and hydrophobicity could be important factors for the adsorption to the air-liquid interface.