RESUMEN
Human kallikrein-1 (hK1) gene was cloned from kidney tissues cDNA, it was inserted into the plasmid pPICZalphaA, then the yeast expression vector pPICZalpha-hK1 was constructed. After transformed into Pichia pastoris host X33, high-level expression transformants were screened by escalating the concentration of Zeocin (from 500 to 700 microg/mL) of YPD plate and medium. When temperature was 30 degrees C, pH 6.0 with induction duration of 64 hours in the 30 L fermenter, the highest yield can reach about 6500 u/L (1.25 g/L). The variation of glycosylation resulted in two kinds of molecules, i.e. rhK1-H with a heavy molecular weight and rhK1-L with a light one. rhK1 was purified from the supernatant through Phenyl hydrophobic interaction, Cu(2+)-charged Chelating and Anion-exchange chromatography. 0.28 g rhK1-H and 0.62 g rhK1-L can be purified from one liter supernatant. The yield recovery was 72% with a purity of > 96%. So far our yield of rhK1 is superior than known recombinant expression method reported by other researchers.
Asunto(s)
Humanos , Secuencia de Aminoácidos , Secuencia de Bases , Cromatografía por Intercambio Iónico , Métodos , Vectores Genéticos , Genética , Riñón , Metabolismo , Datos de Secuencia Molecular , Pichia , Genética , Metabolismo , Proteínas Recombinantes , Genética , Calicreínas de Tejido , GenéticaRESUMEN
Recombinant human interleukin-1 receptor antagonist was expressed in E. coli as an insoluble inclusion body. The inclusion body was dissolved in the 8 M urea and then the solution was diluted untill the concentration of urea became 2 M. By ion exchange chromatography the protein in the solution of 2 M urea was refolded and purified. At last the purity of product is more than 95% and its bioactivity is more than 1 x 10(5) IU/mg while it has little endotoxin. Western-Blotting also indicates that recombinant protein can react with antibodies against anti-hIL-1ra.