RESUMO
A system for the production of mutant recombinant human alpha-fetoprotein (rhAFPO) lacking the glycosylation site has been engineered in the yeast Pichia pastoris. A strain of the methylotrophic yeast Pichia pastoris GS 115/pPICZ?A/rhAFP0, which produces unglycosylated rhAFPO and secretes it to the culture medium, has been constructed. Optimization and scale-up of the fermentation technology have resulted in an increase in the rhAFP0 yield to 20 mg/L. A scheme of isolation and purification of biologically active rhAFP0 has been developed. The synthesized protein has the antitumor activity, which is analogous to the activity of natural human embryonic alpha-fetoprotein.
Assuntos
Proteínas Mutantes/biossíntese , Neoplasias/tratamento farmacológico , Proteínas Recombinantes/biossíntese , alfa-Fetoproteínas/biossíntese , Linhagem Celular Tumoral , Fermentação , Humanos , Proteínas Mutantes/administração & dosagem , Proteínas Mutantes/genética , Pichia/genética , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Saccharomyces cerevisiae/genética , alfa-Fetoproteínas/administração & dosagem , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/isolamento & purificaçãoRESUMO
A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.
Assuntos
Etanol/síntese química , Biossíntese Peptídica , Peptídeos/genética , Saccharomyces cerevisiae/metabolismo , Bacteriocinas/biossíntese , Bacteriocinas/genética , Fermentação , Lactobacillus/efeitos dos fármacos , Pediocinas , Peptídeos/farmacologia , Saccharomyces cerevisiae/genéticaRESUMO
It is shown that Escherichia coli ribosomes carrying poly(Lys)-tRNA can form (p)ppGpp in the presence of stringent factor in the absence of the poly(A) template. Template-independent synthesis of (p)ppGpp is suppressed by tetracycline and partially decreases if deacylated tRNA is omitted.
