UC Irvine

A wide spectrum of therapeutic nanoparticles have been investigated as delivery systems to improve the pharmacological properties of drugs or imaging agents. By utilizing the advantageous properties of nanoparticles such as high surface to volume ratio and unique optical properties, improved delivery has been shown in several different disease applications. Furthermore, nanoparticles can be associated with proteins that can provide the ability to specifically target selected areas or diseased tissues without exposing the rest of the body. In previous work, our lab engineered recombinant protein constructs containing single-chain antibodies to study nanoparticle adhesion to inflammatory molecules. The goal of this work is to advance the recombinant protein expression construct towards two specific goals: 1) site-specific modification of the recombinant proteins with small molecule chemistries using different enzyme/peptide tag systems and 2) create a new panel of adhesion receptors based on I-domains of the integrin LFA-1 for targeting the inflammatory molecule ICAM-1. Specifically, three different enzyme/tag systems are tested and compared using yeast surface display and soluble protein, including Sfp synthase/S6 tag, and Sortase A/LPETG tag, and Lipoic Acid Ligase (LplA)/LAP2 tag. We also insert wild type and mutant I-domains obtained from the integrin Lymphocyte function-associated antigen-1 (LFA-1) into the plasmid vector and transformed into yeast. The establishment of I-domain targeting panel and enzymatic conjugation method will provide a solid foundation for further optimization of adhesion therapeutic nanoparticles.