Sucrase

Sucrase is a yeast-derived enzyme. Sucrase splits sucrose into glucose and fructose (invert syrup) and can be applied for any inversion of sucrose especially liquefied cherry centers, creams, mints, truffles, marshmallow, invert syrup and other fondants. Sucrase is used to improve shelf life of confections. It is available in single, double and triple strengths and is packaged in one, ten and 44 pound containers for ease of use, storage and cost efficiency.

The official name for Sucrase is beta-fructofuranosidase (EC3.2.1.26), which implies that the reaction catalyzed by this enzyme is the hydrolysis of the terminal nonreducing beta-fructofuranoside residues in beta-fructofuranosides. Note that alpha-D-glucosidase, which splits off a terminal glucose unit, can also catalyze this reaction. Note that sucrose can be hydrolyzed relatively easily; the reaction proceeds in an acidic environment without the aid of Sucrase.

Sucrase is mainly used in the food (confectionery) industry where fructose is preferred over sucrose because it is sweeter and does not crystallize as easily. However, the use of Sucrase is rather limited because another enzyme, glucose isomerase, can be used to convert glucose to fructose more inexpensively. For health and taste reasons, its use in food industry requires that Sucrase be highly purified.

A wide range of microorganisms produce Sucrase and can, thus, utilize sucrose as a nutrient. Commercially, Sucrase is biosynthesized chiefly by yeast strains of Saccharomyces cerevisiae or Saccharomyces carlsbergensis. Even within the same yeast culture, Sucrase exists in more than one form. For example, the intracellular Sucrase has a molecular weight of 135,000 Daltons, whereas the extracellular variety has a molecular weight of 270,000 Daltons.

In contrary to most other enzymes, Sucrase exhibits relatively high activity over a broad range of pH (3.5--5.5), with the optimum near pH=4.5. The enzyme activity reaches a maximum at about 55ºC. The Michaelis-Menten values of various enzymes vary widely, but for most enzymes Km is between 2 mM and 5 mM. The Michaelis-Menten value for the free enzyme is typically approx. 30 mm.

Enzyme inhibition is an extremely important area of research in the medical field. For example, lead, mercury, other heavy metals, and nerve gases are extremely poisonous to humans because they are inhibitory to enzymes. For example, Pb^++ can easily react with the sulfhydryl (-SH) groups in a protein.