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Biomedical subjects

J G Gustafsson

Publications and source records attributed to J G Gustafsson.

5 recordsLinked to original sources

Hydroxylamine-induced cleavage of the asparaginyl-glycine motif in the production of recombinant proteins: the case of insulin-like growth factor I.

Hydroxylamine-induced cleavage at the asparaginyl-glycine dipeptide site inserted between the two moieties of recombinant fusion proteins has been used at both the analytical and the preparative scale to obtain the mature protein. In this study a model protein containing a fusion precursor of insulin-like growth factor I was used to investigate the influence of the operating conditions on the cleavage reaction and the formation of undesired side products such as hydroxamate and deamidated analogs. Moreover, the stability of the cleavage site toward deamidation was examined and a chemometric study performed to define the effect of the reaction conditions on the cleavage yield and on the formation of side products.

Amino Acid Sequence↗

Reduction of proteolytic breakdown in microbial homogenates.

Proteolytic enzymes are present in many biological raw materials used for the production of proteins and peptides. Such enzymes are active not only in homogenates of bacteria and yeast but also in ascites liquid and cell culture media used for the production of monoclonals. A new protease substrate was used to determine protease activity in homogenates of E. coli and baker's yeast, which are useful for the production of therapeutically valuable polypeptides. Using this substrate we found that cooling and the addition of protease inhibitors had little effect on the proteolytic activity. Most of the proteolytic activity however could be adsorbed to hydrophobic gel media. Data is given on the protease adsorption at different temperatures and ionic strengths.

Bacteria↗

Protein adsorbents intended for use in aqueous two-phase systems.

Preparation of adsorbents with high partition coefficients in polyethylene glycol-dextran and polyethylene glycol-phosphate systems is described. These adsorbents may be used to carry to carry proteins away from the insoluble cell fragments generated during cell disruption. By chromatographic elution, proteins may be selectively desorbed in a reduced volume.

Adsorption↗