Applications of cellulose-binding module fusion proteins: From bioactive filters to antibody purification.

摘要

Cellulose-binding modules (CBM) are a class of non-catalytic polysaccharide-binding proteins used for a wide-range of biotechnological applications. The research presented here investigated the use of CBMs for two unique applications. The first experiment addresses the increasing contamination of water resources with industrial and natural chemicals. A filtration system was created for the removal of organic compounds from water by molecular and immunoaffinity techniques. Specifically, a CBM was fused to an anti-herbicide antibody fragment (scFv) and immobilized on cellulose-matrices for herbicide sequestration. The scFv-CBM fusion protein was bifunctional; 4.9 mug of fusion protein was immobilized per mg of Avicel microcrystalline cellulose and the scFv portion was capable of binding its antigen, picloram, with similar affinity as scFv alone. In addition, a cellulose column containing immobilized scFv-CBM was capable of binding picloram spiked into a water sample. In the second experiment, a new method was developed for the extraction of plant-produced recombinant antibodies. Specifically, antibody-binding proteins L and G were fused to a CBM, expressed in Pichia pastoris at 25 mg/L, and immobilized on cellulose beads in a single-step. The immobilized reagent was used to purify IgG antibodies from tobacco. The research presented here is pertinent to medicine, the pharmaceutical industry, the environment, and agriculture.