Production and application of high quality stable isotope-labeled human immunoglobulin G1 for mass spectrometry analysis.

Here, we describe the production of stable isotope-labeled human immunoglobulin G1 ([ C]-hIgG1) using [ C]-L-lysine/arginine-labeled hIgG1. The fermentation process was run in shake flasks containing labeled arginine and lysinethat were incorporated into the produced recombinant hIgG1. The [ C]-hIgG1 was purified, and label incorporation was determined to be >99% at all lysine and arginine moieties.

Endotoxin removal and prevention for pre-clinical biologics production.

The removal of endotoxin from protein solutions and its prevention are key to the success of recombinant protein production due to the possible pyogenic response in mammals caused by contaminated samples. In the pre-clinical situation, protein production is often carried out in a non-good manufacturing practice (GMP) setting, utilizing bacterial DNA for transient transfection and non-validated cleaning techniques. Here, we present our findings evaluating various options for endotoxin removal, and propose strategies for endotoxin prevention with emphasis on chromatographic separations, endotoxin-removing membranes and on-column wash strategies.

In vitro assembly of mosaic hepatitis B virus capsid-like particles (CLPs): rescue into CLPs of assembly-deficient core protein fusions and FRET-suited CLPs.

Hepatitis B virus core protein self-assembles into icosahedral, highly immunogenic capsid-like particles (CLPs) that can serve as molecular platforms for heterologous proteins. Insertion into the centrally located c/e1 epitope leads to surface display, fusion to the C terminus to internal disposition of the foreign domains. However, symmetry-defined space restrictions on the surface and particularly inside the CLPs limit the size of usable heterologous fusion partners.