Development of expression systems for the production of recombinant human Fas ligand extracellular domain derivatives using <em>Pichia pastoris</em> and preparation of the conjugates by site-specific chemical modifications: A review

Abstract

Human Fas ligand extracellular domain (hFasLECD) is a biomedically important glycoprotein with three potential N-linked carbohydrate-chain attachment sites. hFasLECD can induce an apoptotic cell-death in many malignant cells. Hence, the creation of novel molecular tools exhibiting useful biological activities, based on the exploitation of this protein domain as their components, opens up a great possibility of the advancements in future medical applications. This review mainly focuses on the development of expression systems for obtaining various derivatives of recombinant hFasLECD using Pichia pastoris and the preparation of the conjugates by site-specific chemical modifications of the expressed products. Firstly, a brief introduction of human Fas ligand protein and an overview of the previous works, on the heterologous expression systems for recombinant hFasLECD as well as the associated derivatives aimed at medical applications, were described. Then, the experimental results, obtained during our investigations into the development of the expression systems for the recombinant hFasLECD derivatives using chemically synthesized artificial genes in Pichia pastoris, were summarized. After that, the current state of the methodology for preparation of the hFasLECD conjugates by site-specific chemical modifications, and the functional characterizations of the prepared conjugates, were presented. Finally, conclusions, including a relevant discussion and future perspectives, are provided.