Ultrasound

Amino acid

Biology

Endocrinology

Biochemistry

Radiology

Protein secondary structure

Microstructure

Tryptophan

Internal medicine

Crystallography

Medicine

Chemistry

Biophysics

Phenylalanine

Random coil

Gonad

The effects of ultrasound with different powers (0-500 W) on the structure and stability of protein from sea cucumber gonad were investigated, according to the changes in phenylalanine (Phe), α-helix, β-sheet, tryptophan (Trp), surface hydrophobicity, particle size distribution, microstructure and amino acid (AA). With the increase in ultrasound power, the contents of Phe, β-sheet and Trp, surface hydrophobicity and particle size first increased and then decreased, while α-helix content was opposite. Compared with the non-ultrasound group, the content of α-helix and random coil significantly decreased by 24.71% and 22.33% in the 200 W ultrasound group, while Phe content, β-sheet content, fluorescence intensity (FI), the surface hydrophobicity and hydrophobic AA significantly increased by 12.77%, 75.91%, 7.90%, 15.61% and 7.00%, respectively (P < 0.05). According to microstructure analysis, after 200 W ultrasound treatment, the protein particles became smaller and more uniform, and the protein structure was much looser than that without ultrasound treatment. Overall, the side chain, secondary, and tertiary structure of protein from sea cucumber gonad were unfolded under ultrasound treatment, which exposed more hydrophobic groups and decreased protein aggregation, and the effect of ultrasound with 200 W on the protein structure was prominent.

Effects of different ultrasound powers on the structure and stability of protein from sea cucumber gonad