反应详情

温度

28 °C

An amount of penicillin acylase enzyme, either free or immobilized on the carrier, sufficient to contain about 50 I.U. of activity, was suspended in 60 ml of 7.5-pH phosphate buffer. The mixture was maintained at 28° C. in a vessel connected to a pH controller which electrometrically determined the pH and metered in sufficient 0.8 N sodium hydroxide solution to maintain the pH at approximately 8.0. A solution containing 5 g of penicillin G potassium salt in phosphate buffer, also at 28° C., was added to the vessel, and the rate of formation of phenylacetic acid by the enzyme-catalyzed hydrolysis of the penicillin G was determined from the rate of addition of sodium hydroxide solution to maintain the pH. The liquid in the vessel was sampled upon addition of the penicillin G salt and after 10 and 30 minutes. These samples (0.5 ml) were immediately mixed with 3 ml of a solution of 1 ml of 0.05 M sodium hydroxide, 2 ml of 20% acetic acid and 0.5% (weight-volume) p-dimethylaminobenzaldehyde/methanol, and were allowed to stand for 10 minutes. The amount of 6-aminopenicillanic acid formed was determined by spectrophotometrically measuring the light absorption of the mixture at a wave length of 415 nm.

1. temperatureto maintain the pH at approximately 8.0
2. additionalso at 28° C., was added to the vessel
3. temperatureto maintain the pH
4. customafter 10 and 30 minutes