The optimum temperature of salicin hydrolysis by enzyme action is independent of the concentrations of substrate and enzyme / by Arthur Compton.
- Compton, Arthur.
- Date:
- [1914?]
Licence: Public Domain Mark
Credit: The optimum temperature of salicin hydrolysis by enzyme action is independent of the concentrations of substrate and enzyme / by Arthur Compton. Source: Wellcome Collection.
4/14 page 246
![The successive stages in the inquiry may be briefly summarised as follows: (1) a preliminary determination of the activity of the specimen under certain chosen conditions as regards the concentration of the substrate, the tem¬ perature, and the duration of the experiment; (2) a preliminary determina¬ tion of the optimum temperature with the quantity of enzyme found capable of producing 50 per cent, hydrolysis of the substrate under the above conditions; (3) a determination of the activity curves of the enzyme at the temperature thus found, in an action of the same duration for five concentra¬ tions of the substrate M/5, M/10, M/15, M/30, and M/50 ; (4) a determina¬ tion of the optimum temperature of the enzyme for each of the five concentrations of the substrate in presence of a constant enzyme concentra¬ tion ; (5) a determination of the optimum temperature of the enzyme for each of the five concentrations of the substrate with quantities of enzyme indicated by the activity curves as capable of producing 70 per cent, hydrolysis of the substrate in the given time: (6) a determination of the optimum temperature of the enzyme for a constant concentration of the substrate in presence of different enzyme concentrations. The preliminary determination of the activity of the enzyme was carried out in a M/5 dilution of the substrate during a period of 15 hours at 40°. The piactical details were as follows: 286 mgrm. of salicin and varying quantities of the enzyme dissolved in 5 cm.3 of water, specially purified by redistillation under diminished pressure, were introduced into each of a series of seven clean Jena glass test-tubes. The tubes were incubated for 15 hours in a water thermostat at 40°, after which the enzyme action was stopped by rapidly cooling the tubes and then adding to each a drop of concentrated solution of ammonium hydroxide. The proportion of glucoside hydrolysed in each tube was estimated by the increase of reducing power, measured by the method of Bertrand.* The numbers obtained are set out in Table I. Table I. Quantity of enzyme. Salicin hydrolysed. mgrm 0-6 1 5 3 0 4*5 6 0 7-0 9 0 per cent. 34 *8 67 *2 86 -8 91 ’2 91 -7 96 -1 97 *0 * ‘ Bull. Soc. Chim.’ [3], 1906, vol. 35, p. 1285.](https://iiif.wellcomecollection.org/image/b30620971_0004.jp2/full/800%2C/0/default.jpg)
