SEARCH

SEARCH BY CITATION

Abstract

  1. Top of page
  2. Abstract
  3. REFERENCES

The isolation of bacterially synthesized, recombinant-DNA-derived, bovine growth hormone (r-bGH) with native structure is described. The r-bGH is found in insoluble form, in a pellet fraction, after cell breakage and centrifugation. Cell envelope components (protein, lipid, endotoxin) and nucleic acids are selectively removed from the pellet fraction by an EDTA/lysozyme/deoxycholate extraction. We demonstrate that the r-bGH is largely reduced until solubilized using 6 M guanidine/HCl. Air oxidation is then carried out, in the presence of the guanidine/HCl. The oxidation results in a mixture of about one-third disulfide-linked oligomers and two-thirds oxidized monomer. The latter may include some incorrectly oxidized material, but appears to be mostly correctly oxidized. The oxidized monomer is isolated by gel filtration in the presence of guanidine/HCl. Subsequent guanidine/HCl removal leads to refolded, oxidized r-bGH. All steps in the procedure, in particular the oxidation and refolding steps, can be carried out at relatively high protein concentrations.

Abbreviations
bGh

bovine growth hormone

r-bGH

recombinant-DNA-derived bGH

SDS

sodium dodecyl sulfate

HPLC

high-performance liquid chromatography

BLM buffer

0.25% (w/v) sodium bicarbonate, 0.2% (w/v) α-lactose, 0.2% (w/v) mannitol, pH 8.5

REFERENCES

  1. Top of page
  2. Abstract
  3. REFERENCES