Understanding interactions between four main fishy compounds and grass carp myofibrillar proteins using the SPME-GC–MS, multiple spectroscopy, and molecular docking

The interaction mechanism between four fishy compounds and myofibrillar proteins of grass crap was explored using solid phase microextraction-gas chromatography-mass spectrometry, multispectroscopy, and molecular docking. The result showed that the binding abilities of myofibrillar protein for the fishy compounds decreased in the order of decanal, octanal, hexanal, and 1-octen-3-ol. The interaction between myofibrillar proteins and four fishy compounds affected the aromatic amino acid residue microenvironment. The predominant binding force of myofibrillar proteins to the three aldehydes was hydrophobic, while those to 1-octen-3-ol were hydrogen bonds and van der Waals forces, and binding sites of these compounds occurred near tryptophan and tyrosine. A significant reduction in α-helical content and surface hydrophobicity in grass carp myofibrillar protein upon interaction with the four fishy compounds. Molecular docking confirmed that the different functional groups and chain lengths of the fishy components resulted in different binding sites and binding free energies with grass carp protein.