Insights into the structural characteristic of rabbit glycated myofibrillar protein with high solubility in low ionic strength medium

To analyze structural characteristic of rabbit glycated myofibrillar protein (GMP) with different solubility in low ionic strength medium, changes in fourier transform infrared spectroscopy, Raman spectroscopy analysis, intrinsic fluorescence analysis, UV absorption spectra, surface hydrophobicity, total sulfhydryl and carbonyl contents, and sodium dodecyl sulfate polyacrylamide gel electrophoresis were determined. The results reflected that GMP with 75.07% solubility in low ionic strength medium had less α-helix and more random coil than GMP with other solubility. The difference in the tertiary structure of GMP with different solubility was also detected, including that intrinsic fluorescence intensity of GMP gradually reduced and a red shift of peak positions of UV absorption spectrum of GMP with solubility increased. Furthermore, the total sulfhydryl content of GMP with 75.07% solubility was much lower than other groups, and carbonyl content of GMP was significantly increased when solubility was above 15.10%. Results also suggested that the electrophoretic mobility of the protein chain of GMP with 75.07% solubility was minimum among all groups. In conclusion, the structure of rabbit GMP with 75.07% solubility in low ionic strength medium was different from GMP with other solubility due to glycation process, and protein oxidation may be also response for the structure changes. •GMP with higher solubility in low ionic strength medium had more random coil.•GMP with higher solubility in low ionic strength medium had lower sulfhydryl content.•Protein oxidation may be also response for the GMP structure changes.