title: High-level production of animal-free recombinant transferrin from Saccharomyces cerevisiae.
abstract: BACKGROUND
  Animal-free recombinant proteins provide a safe and effective alternative to tissue or serum-derived products for both therapeutic and biomanufacturing applications. While recombinant insulin and albumin already exist to replace their human counterparts in cell culture media, until recently there has been no equivalent for serum transferrin.
  
  
  RESULTS
  The first microbial system for the high-level secretion of a recombinant transferrin (rTf) has been developed from Saccharomyces cerevisiae strains originally engineered for the commercial production of recombinant human albumin (Novozymes' Recombumin® USP-NF) and albumin fusion proteins (Novozymes' albufuse®). A full-length non-N-linked glycosylated rTf was secreted at levels around ten-fold higher than from commonly used laboratory strains. Modification of the yeast 2 μm-based expression vector to allow overexpression of the ER chaperone, protein disulphide isomerase, further increased the secretion of rTf approximately twelve-fold in high cell density fermentation. The rTf produced was functionally equivalent to plasma-derived transferrin.
  
  
  CONCLUSIONS
  A Saccharomyces cerevisiae expression system has enabled the cGMP manufacture of an animal-free rTf for industrial cell culture application without the risk of prion and viral contamination, and provides a high-quality platform for the development of transferrin-based therapeutics.
authors.affiliation: Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham NG71FD, UK. cjaf@novozymes.com
authors.forename: Christopher J A
authors.initials: CJ
authors.lastname: Finnis
authors.forename: Tom
authors.initials: T
authors.lastname: Payne
authors.forename: Joanna
authors.initials: J
authors.lastname: Hay
authors.forename: Neil
authors.initials: N
authors.lastname: Dodsworth
authors.forename: Diane
authors.initials: D
authors.lastname: Wilkinson
authors.forename: Philip
authors.initials: P
authors.lastname: Morton
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Saxton
authors.forename: David J
authors.initials: DJ
authors.lastname: Tooth
authors.forename: Robert W
authors.initials: RW
authors.lastname: Evans
authors.forename: Hans
authors.initials: H
authors.lastname: Goldenberg
authors.forename: Barbara
authors.initials: B
authors.lastname: Scheiber-Mojdehkar
authors.forename: Nina
authors.initials: N
authors.lastname: Ternes
authors.forename: Darrell
authors.initials: D
authors.lastname: Sleep
mesh_terms: D002452:Cell Count; D005285:Fermentation; D006031:Glycosylation; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014168:Transferrin / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D018832:Molecular Chaperones; D011994:Recombinant Proteins; D014168:Transferrin; D019704:Protein Disulfide-Isomerases