RT Journal Article SR Electronic(1) A1 Swennen, Dominique A1 Paul, Marie-Françoise A1 Vernis, Laurence A1 Beckerich, Jean-Marie A1 Fournier, Alain A1 Gaillardin, ClaudeYR 2002 T1 Secretion of active anti-Ras single-chain Fv antibody by the yeasts Yarrowia lipolytica and Kluyveromyces lactis JF Microbiology, VO 148 IS 1 SP 41 OP 50 DO https://doi.org/10.1099/00221287-148-1-41 PB Microbiology Society, SN 1465-2080, AB Yarrowia lipolytica and Kluyveromyces lactis secretion vectors were constructed and assessed for the expression of heterologous proteins. An anti-Ras single-chain antibody fragment (scFv) coding sequence was fused in-frame to different pre- or prepro-regions, or downstream from a reporter secretory gene (Arxula adeninivorans glucoamylase), separated by a Kex2 protease (Kex2p)-like processing sequence. Both organisms are able to secrete soluble scFv, with yields depending on the nature of the expression cassette, up to levels ranging from 10 to 20 mg l−1. N-terminal sequence analysis of the purified scFv showed that fusions are correctly processed to the mature scFv by a signal peptidase or a Kex2p-type endoprotease present in Y. lipolytica and K. lactis. The scFv protein also retains the capacity to bind to a glutathioneS-transferase (GST)–Harvey-RasVal12 fusion, indicating that the antibody is functional. These results indicate that the yeasts Y. lipolytica and K. lactis have potential for industrial production of soluble and active scFv., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-148-1-41