Structural changes induced in proteins by therapeutic ultrasounds.
The structural effect induced by therapeutic ultrasound on proteins in aqueous solution has been investigated with FTIR spectroscopy, UV-VIS spectroscopy, circular dichroism and light scattering. Six proteins (cytochrome, lysozyme, myoglobin, bovine serum albumin, trypsinogen, and alpha-chymotrypsinogen A) with different molecular weight and secondary structure have been studied. The experiment has been performed using an ultrasound source at resonant frequency of 1 MHz and sonication times of 10, 20, 30, 40, 50, and 60 min. A different behaviour of proteins under sonication depends on the dominant secondary structure type (alpha-helix or beta-sheets) and on the grade of the ordered structure. The results suggest that the free radicals, produced by water sonolysis, have an important role in the changes of structural order.
Marchioni
C
C
Dipartimento di Fisica, Università Di Roma Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy.
Riccardi
E
E
Spinelli
S
S
Dell'Unto
F
F
Grimaldi
P
P
Bedini
A
A
Giliberti
C
C
Giuliani
L
L
Palomba
R
R
Congiu Castellano
A
A
D002942:Circular Dichroism; D005609:Free Radicals; D008970:Molecular Weight; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D012542:Scattering, Radiation; D012815:Signal Processing, Computer-Assisted; D017550:Spectroscopy, Fourier Transform Infrared; D014464:Ultrasonic Therapy; D014465:Ultrasonics
D005609:Free Radicals; D011506:Proteins