title: Host cell properties and external pH affect proinsulin production by Saccharomyces yeast.
abstract: The expression of a hybrid gene encoding an alpha-factor prepro leader peptide-miniproinsulin (MPI) fusion [MPI is the same as the LysArg human insulin precursor described by Thim et al. (1986)] was tested in a series of isogenic yeast strains to investigate the influence of some genetic and physiological factors on heterologous production in yeast. We found that: (i) an MF alpha 1 gene disruption in haploid cells, as well as MF alpha 1 gene product expression in diploid cells, do not affect the MPI secretion level; (ii) under conditions of exogenous leucine availability, MPI production is hindered by leucine auxotrophy (a leu2 mutation); (iii) rho- mutations increase the per-cell MPI yield approximately three-fold; (iv) the MPI yield is apparently dependent on the pH of the culture medium: the higher the external pH, the larger the per-cell MPI yield.
authors.affiliation: Institute of Genetics and Selection of Industrial Microorganisms, Moscow, Russia.
authors.forename: D G
authors.initials: DG
authors.lastname: Kozlov
authors.forename: N
authors.initials: N
authors.lastname: Prahl
authors.forename: B D
authors.initials: BD
authors.lastname: Efremov
authors.forename: L
authors.initials: L
authors.lastname: Peters
authors.forename: R
authors.initials: R
authors.lastname: Wambut
authors.forename: I V
authors.initials: IV
authors.lastname: Karpychev
authors.forename: M A
authors.initials: MA
authors.lastname: Eldarov
authors.forename: S V
authors.initials: SV
authors.lastname: Benevolensky
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000378:metabolism; D008969:Molecular Sequence Data; D011003:Ploidies; D011384:Proinsulin / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology
chemical_list: C060793:miniproinsulin; D012710:Serum Albumin, Bovine; D011384:Proinsulin; D007930:Leucine