title: Culture pH affects expression rates and glycosylation of recombinant mouse placental lactogen proteins by Chinese hamster ovary (CHO) cells.
abstract: Glycosylation patterns and specific expression rates of the recombinant protein mouse placental lactogen-I (mPL-I) by Chinese hamster ovary (CHO) cells varied significantly over the extracellular pH (pHe) range of 6.1 to 8.7. The maximum specific mPL-I expression rates occurred between pHe 7.6 and 8.0. The pHe effect on protein expression was confirmed using a different CHO cell expressing the unglycosylated recombinant protein mouse placental lactogen-II (mPL-II). Decreases in the extent of glycosylation of mPL-I were observed at low (below 6.9) and high (above 8.2) pHe values. The pHe dependent variations in mPL-I accumulation in the supernatant as well as in glycosylation patterns were not the result of enzymatic degradation in the culture medium.
authors.affiliation: Department of Chemical Engineering, Northwestern University, Evanston, IL 60208.
authors.forename: M C
authors.initials: MC
authors.lastname: Borys
authors.forename: D I
authors.initials: DI
authors.lastname: Linzer
authors.forename: E T
authors.initials: ET
authors.lastname: Papoutsakis
mesh_terms: D000818:Animals; D016466:CHO Cells / Q000378:metabolism; D002240:Carbohydrate Sequence; D006224:Cricetinae; D017077:Culture Media, Conditioned; D015870:Gene Expression; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D051379:Mice; D008969:Molecular Sequence Data; D010928:Placental Lactogen / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins
chemical_list: D017077:Culture Media, Conditioned; D011994:Recombinant Proteins; D010928:Placental Lactogen