Stabilization of Protein by Sugar Surfactant

Abstract

Protein is one of the substances that are indispensable in the food and pharmaceutical industries and, however, is apt to lose its native conformation and consequently bioactivity under nonphysiological conditions. Hence, to date, the methodologies to protect proteins against denaturation have been investigated and various substances including sugars, amino acids, and certain types of polymers have been known to serve to maintain the protein conformation under different conditions. On the other hand, the sugar surfactants that are frequently used as food additives have been found to stabilize protein in various situations. Herein, the effectiveness of sugar surfactant as a protein stabilizing agent against denaturation in aqueous solution, freezing step, and freeze-drying are demonstrated as well as the denaturation pathways of proteins. Particularly, this review focuses on the differences among the protein stabilizing effects of various sugar surfactants in freezing and freeze-drying. The impacts on the protein stabilizing characteristics by alkyl chain length, sugar head group structure, and ester/ether bondings of sugar surfactant are discussed as well as the possible stabilizing mechanism.