Stech, M.M.StechMerk, H.H.MerkSchenk, J.A.J.A.SchenkStöcklein, W.W.StöckleinWüstenhagen, D.D.WüstenhagenMicheel, B.B.MicheelDuschl, C.C.DuschlBier, F.F.F.F.BierKubick, S.S.Kubick2022-03-042022-03-042012https://publica.fraunhofer.de/handle/publica/23091610.1016/j.jbiotec.2012.08.020Cell-free protein synthesis is of increasing interest for the rapid and high-throughput synthesis of many proteins, in particular also antibody fragments. In this study, we present a novel strategy for the production of single chain antibody fragments (scFv) in a eukaryotic in vitro translation system. This strategy comprises the cell-free expression, isolation and label-free interaction analysis of a model antibody fragment synthesized in two differently prepared insect cell lysates. These lysates contain translocationally active microsomal structures derived from the endoplasmic reticulum (ER), allowing for posttranslational modifications of cell-free synthesized proteins. Both types of these insect cell lysates enable the synthesis and translocation of scFv into ER-derived vesicles. However, only the one that has a specifically adapted redox potential yields functional active antibody fragments. We have developed a new methodology for the isolation of functional target proteins based on the translocation of cell-free produced scFv into microsomal structures and subsequent collection of protein-enriched vesicles. Antibody fragments that have been released from these vesicles are shown to be well suited for label-free binding studies. Altogether, these results show the potential of insect cell lysates for the production, purification and selection of antibody fragments in an easy-to-handle and time-saving manner.en660610620journal article