title: Stable production of recombinant pro-urokinase by human lymphoblastoid Namalwa KJM-1 cells: host-cell dependency of the expressed-protein stability.
abstract: Human pro-urokinase (pro-UK) gene was engineered for expression in mammalian cells. The stability of recombinant pro-UKs produced by two kinds of cells, Chinese hamster ovary (CHO) and human lymphoblastoid Namalwa KJM-1 cells, were compared. The pro-UK expressed in CHO cells in serum-free medium was degraded by cysteine endopeptidase secreted by CHO cells. This endopeptidase was inhibited by p-chloromercuribenzonate (PCMB) and leupeptin more efficiently than by aprotinin. On the other hand, the pro-UK expressed in Namalwa KJM-1 cells was not degraded, resulting in the stable production of pro-UK at a rate of 2-3 micrograms/10(6) cells/day by use of a gene amplification method with dihydrofolate reductase (DHFR) in serum-free medium. Thus, Namalwa KJM-1 cells showed the desired characteristics as a host cell for the production of recombinant proteins. The stability of recombinant proteins in heterologous systems may vary depending on the host cells.
authors.affiliation: Tokyo Research Laboratories, Kyowa Hakko Co., Ltd., Japan.
authors.forename: M
authors.initials: M
authors.lastname: Satoh
authors.forename: S
authors.initials: S
authors.lastname: Hosoi
authors.forename: H
authors.initials: H
authors.lastname: Miyaji
authors.forename: S
authors.initials: S
authors.lastname: Itoh
authors.forename: S
authors.initials: S
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D017077:Culture Media, Conditioned; D004247:DNA; D004792:Enzyme Precursors / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004795:Enzyme Stability; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D013379:Substrate Specificity; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D017077:Culture Media, Conditioned; D004792:Enzyme Precursors; D011994:Recombinant Proteins; D004247:DNA; D014568:Urokinase-Type Plasminogen Activator; C067551:saruplase