3.5.5.5 15 55 exposure of the enzyme at 15, 25, and 35°C for 5 h causes 8%, 15%, and 28% decrease in arylacetonitrilase activity, respectively. A further increase in the temperature to 45 and 55°C results in 58% and 90% decrease in activity, respectively. The half-life of this enzyme at 15, 25, 35, 45, 50, and 55°C is 31 h, 16 h, 9 h, 4 h 30 min, 3 h 20 min, and 2 h 40 min, respectively 733546 3.5.5.5 20 - 40 h, about 50% loss of activity 756265 3.5.5.5 25 - purified recombinant enzyme, pH 8.0, 1 h, 90% activity remaining 718670 3.5.5.5 25 35 purified recombinant enzyme, pH 8.0, 1 h, stable 718670 3.5.5.5 30 - 10 h, about 50% loss of activity 756265 3.5.5.5 30 - 6 h, 87% residual activity 667345 3.5.5.5 30 - and below, 30 min, stable in 10 mM potassium phosphate buffer, pH 7.5 32503 3.5.5.5 35 - 30 min, in 10 mM potassium phosphate buffer, pH 7.5, 25% loss of activity 32503 3.5.5.5 35 - purified recombinant enzyme, pH 8.0, 1 h, 80% activity remaining 718670 3.5.5.5 35 65 purified recombinant enzyme, labile at higher temperature, half-life of 57 min at 40°C, 42 min at 45°C, and 20 min at 55°C, respectively. The activity decreases markedly above 55°C 719629 3.5.5.5 40 - 3 h, about 50% loss of activity 756265 3.5.5.5 40 - 30 min, in 10 mM potassium phosphate buffer, pH 7.5, inactivation 32503 3.5.5.5 40 - half-life 76 min 667345 3.5.5.5 40 - half-life: 45 h 758206 3.5.5.5 40 - purified recombinant enzyme, pH 8.0, 1 h, 40% activity remaining 718670 3.5.5.5 40 - purified recombinant enzyme, pH 8.0, 1 h, 60% activity remaining 718670 3.5.5.5 45 - and above, purified recombinant enzyme, pH 8.0, 1 h, no activity remaining 718670 3.5.5.5 45 - half-life: 36 h 758206 3.5.5.5 45 - purified recombinant enzyme, pH 8.0, 1 h, 20% activity remaining 718670 3.5.5.5 50 - half-life 9 min 667345 3.5.5.5 50 - half-life: 13 h 758206 3.5.5.5 50 - the enzyme retains 50% of its initial activity after incubation at 50°C for 30 min 733558 3.5.5.5 50 60 purified recombinant enzyme, pH 8.0, 1 h, about 10% activity remaining 718670 3.5.5.5 50 70 good thermal stability at 50°C, the enzyme completely loses its activity after heat-treatment at 70°C for 30 min 687882 3.5.5.5 65 - complete loss of activity 670163