Protein Folding

A core competence of Scil Proteins comprises in vitro folding of proteins from inclusion bodies at an industrial or laboratory scale. Many, especially human derived therapeutic proteins, are secreted from cells thus being exposed to an oxidizing environment. Consequently disulfide bonds, formed between two sulfhydryl groups of cystein residues, play an important role for the protein conformation and stability. In bacterial systems, where the cytoplasm is characterized by reducing conditions, disulfide bonds cannot be formed efficiently. Therefore many of such proteins are produced as inactive aggregates, so called inclusion bodies, for example, in E. coli.

Nevertheless, protein production via inclusion bodies and subsequent refolding procedures provides a cost efficient alternative compared to the expense of eukaryotic cell culturing. It is also a well established method for proteins which are toxic for the host organism in the soluble form or are rapidly degraded by endogenous proteases.
 

Scil Proteins Services has refolded and purified growth factors, hormones, kinases, viral proteins, proteases, and enzymes for numerous diagnostic, pharmaceutical, and biotech companies. Further, a broad range of experience has been gathered with proteins such as G-CSF, tPA, insulin, antibody Fab-fragments, single chain antibodies (scFv), human NGF, BMP, proNGF and proBMP.