Immobilization of Proteins in Alginate: Functional Properties and Applications

Alginate has revolutionized the way in which proteins and enzymes are used in daily life, right from food, textiles, medicines and surgical advancement to environment. Alginate is a biopolymer with unique physical and chemical properties that makes it functionally an ideal material for attachment with proteins. Immobilization of enzymes on alginate is well known to show altered catalytic functions and improved operational stability with no or minimal drawbacks. The GRAS (Generally Recognized as Safe) status of alginate enables it to be readily used as an encapsulation material for food proteins for their better gastrointestinal absorbance, and also in delivery of several proteins and peptides for their therapeutic effects. The exclusive interactions of alginate with proteins as a function of ionic strength, pH and metallic ions make it a support of choice for purification of enzymes and proteins by simple chromatographic separations and affinity precipitation. However biomedical in vivo use of alginate, specifically in tissue engineering, necessitates the use of extra pure form of alginate. This review highlights the impact of interactions between proteins and alginate on the functional properties of the proteins. The review also emphasizes certain core applications areas where alginate is used to a large extent.