Effect of hydrostatic pressure on aggregation and viscoelastic properties of Tilapia (Orechromis niloticus) myosin

Hydrostatic pressures from 500 to 2000 atmospheres (atm) were applied at 0 degreesC to determine the aggregation and viscoelastic properties of tilapi a (Orechromis niloticus) myosin. Native myosins were present as long, linea r, and single filaments. After a 500-atm treatment, these filaments unfolde d and their volume decreased. Upon 1000-atm and 1500-atm treatments, myosin s aggregated and formed inseparable network structures. Further, they trans formed from viscous sol to elastic gels with a pressure of 500 to 1000 atm. At 2000 atm, the myosin formed irregular aggregates. This study reveals th at at 500 atm, myosins unfolded; at 1000 atm, they aggregated, and beyond 1 500 atm, they formed both a precipitate and gel.