Purification and assay of kinase-active EGF receptor from mammalian cells by immunoaffinity chromatography.

The epidermal growth factor (EGF) receptor possesses intrinsic protein-tyrosine kinase activity, and both overexpressed wild-type and mutated forms have been associated with many types of cancers. Therefore, understanding the mechanisms that modulate receptor activity and function is essential to the development of treatments for many of these cancers. However, to address this issue by either conventional or high-throughput screening methods requires the availability of large amounts of highly purified and active EGF receptor.