TRUELY HUMAN - RECOMBINANT HUMAN PROTEINS EXPRESSED IN HUMAN CELLS

Many human proteins undergo posttranslational modifications that greatly affect their bioactivity, stability, folding, oligomerization and other properties. Although non-human cell expression systems can typically yield high amounts of protein, these systems often do not make an authentic human protein. The altered properties can include solubility, binding affinities and biological activity, among others. Ideally, recombinant human proteins should be produced from human cells, yielding more human-like proteins in terms of both physical properties and biochemical functions.

We have recently developed an array of proteins that are expressed in human cells, and therefore mimic native human proteins. These proteins are accurately glycosylated, a main difference compared to non-human cells-expressed proteins. They also show extremely low levels of endotoxin, as well as better bioactivity. Because their properties are most similar to the native protein, such proteins can serve as accurate biomarker standards in various diagnostic assays. We have used this expression system to develop heavy proteins (i.e. proteins labeled with heavy stable isotopes), which can be utilized as standards in clinical mass-spectrometry.