Activation and denaturation of hydrolases in dry and humid supercritical carbon dioxide (SC-CO2)

Enzymatic activity and conformational and morphological studies of four commercial lipases treated with supercritical carbon dioxide

“…However, rapid depressurization (240 kg CO 2 m -3 min -1 ), and several depressurization cycles were conducted. As a consequence, a rough and cracked 18 surface with an apparent increase of porosity can be appreciated after SC-CO 2 treatment in 10,000x magnifications of Figs. 7 b,c and 8 b,c.…”

“…Gieβauf and Gamse [15] reported that thermal stability of free enzymes depends on many factors such as the presence of unstable impurities or stabilizers. Accordingly, Bauer et al [18] related the activity loss of esterase EP10 from Burkholderia gladioli after SC-CO 2 treatment at 75 ºC to the presence of impurities in the enzyme preparation.…”

Effects of Water on Enzyme Performance with an Emphasis on the Reactions in Supercritical Fluids

“…Incubating crude PPL caused a decrease of enzyme activity towards artificial substrates with shortchain triglycerides such as triacetin and tributyrin. Bauer et al (2000) also observed a clear increase of activity after treatments with 100, 200 and 300 µL added water towards artificial substrates such as 1,2-o-dilauryl-racglycero-3-glutaric acid-resorufin ester (DGGR) and triolein with an optimum at 100 µL added water. They indicated that the observed results were due to the activation of the main enzyme in the preparation and denaturation of the hydrolase impurities.…”

“…Partial denaturation of hydrolases has been reported by Bauer et al (2000) in the hydrolysis of artificial substrates using porcine pancreatic lipase (PPL) at 150 bar and 75 • C for 24 h in humid SCCO 2 . That enzyme preparation contained a significant amount of hydrolase as impurities, which were mainly active towards short-chain triglycerides rather than long chain triglycerides.…”

A Review on the Effects of Supercritical Carbon Dioxide on Enzyme Activity

“…Giessauf and Gamse [ 43 ] reported a several-fold increase in the activity of lipase from porcine pancreas after its exposure to carbon dioxide at 15 MPa 75 °C for 24 h. The activity was measured using 1,2- O -dilauryl- rac -glycero-3-glutaric acid resorufin ester (DGGR) as substrate and the maximum achieved increase in the activity was by 760%. The influence of the temperature, pressure and humidity of SC-CO 2 and that of the number of pressurization and depressurization steps on the catalytic activity and stability of enzymes was examined in [ 44 ]. The treated enzymes were crude and a purified preparation of esterase EP10 from Burkholderia gladioli , lipase from Candida rugosa and esterase from porcine liver.…”