Influence of Glucose and Fructose on the Rate of Hydrolysis of Sucrose by Iiwertase from Honey.*

When the rate of hydrolysis of sucrose, by invertase from honey, is plotted against time, the graph obtained was found, by Nelson and Cohn (I), to indicate an acceleration at the beginning of the reaction. The effect is represented by the first part of Curve C .in Fig. 1. This increase in the rate of hydrolysis is rather unusual since invertase action, when the invertase is obtained from bottom yeast, does not show this effect. The present paper is, therefore, an account of experiments carried out with the purpose of making a further study of this effect. The first cause which suggested itself is the influence of invert sugar on the rate of hydrolysis of the sucrose. Consequently, several hydrolyses have been run, using sucrose solutions containing added glucose and fructose. The method of procedure employed was to make up solutions containing the desired concentrations of sucrose, added hexose, and buffer, usually sodium citrate and hydrochloric acid, so as to furnish the required hydrogen ion concentration. The hydrolyses were run in a thermostat and samples taken at definite time intervals during the course of the reaction. The samples were treated with definite quantities of sodium carbonate solution to interrupt the enzyme action and to bring about mutarotation of the reducing sugars present. The degree of rotation of the samples was determined with mercury light. The invertase EL was prepared from honey according to themethod described by‘ Nelson and Cohn (1).