Analysis Of Proteins Release From Escherichia Coli After High Hydrostatic Pressure

The phenomena of pressure influence bioprocesses have been studied for decadesand pressure is thought to be a potential biotechnology in vast industrial fields. Thefinding of barophilic organism expand our knowledge of the variation of thebiological community, this kind of life have evolutionary adapted to grow andproliferate in high pressure, in contrast, high pressure is lethal to normal life althoughsome non-barophiles tolerant ultimate pressure in ranges of time. Base on itssterilizing effect, high hydrostatic pressure which is considered to be a potential foodpreservation method has been studied for decades. We have already known theaffections of pressure on biological processes are pleiotropic, pressure disassociateprotein, inactive enzymes, disrupt membrane, trigger transposons activation, et al. Butthe direct molecular target of its bactericidal effect is still unclear.Recently, pressurization promotes protein release, company with it dissociatesprotein aggregates in heterologous protein expression were found, pressure couldbecome a convenient and efficient method in recombinant protein purification. in ourexperiment, exponential-phase E.coli was chose for the pressurized cell, proteinreleased from cell was collected and compared to whole protein extraction by usingSDS-PAGE, we found the composition between those samples were not identical,which release sample has simpler brand pattern. It indicate that protein release outsidefrom cell under high pressure is not because of membrane rupture, but a selectiveprocess, a specific kind of protein were chose to release, others would stay inside.Then we compare pressure treated protein samples, they are different too, whenpressure elevated, not only protein concentration increase but also the spots numberincrease in2D-PAGE, which means new kinds of protein release outside. Dateanalysis shows that neither the molecular weight nor PI is the primary factor thatdetermines which kinds of protein could release outside. Protein location wasassumed to be the derect reason. As far as we know this is the first time to use2D-PAGE to reveal the composition of protein release from high hydrostatic pressure and the theoretically apply pressure on recombination protein purification in situ,Further work need to be done.