Quantitative determination of recombinant fibroblast growth factor receptor in baculovirus-infected insect cell cultures.

Members of the fibroblast growth factor protein family are involved in several biologically important processes, including angiogenesis, wound healing, and tumor growth and metastasis. Interactions of basic fibroblast growth factor (bFGF) and its receptors are of considerable pharmacological importance. Attempts were made to produce gram quantities of a soluble extracellular form of basic fibroblast growth factor receptor type 1 (bFGFR1) in order to study the energetics of its interaction with bFGF. The aim of the present study was to develop a method for monitoring changes in concentration of bFGFR1 during its production by large-scale baculovirus-infected insect cell culture. A simple reverse-phase high-performance liquid chromatographic assay was developed for direct determination of the soluble receptor secreted into insect cell-culture media. The method permitted cell-culture samples containing varying amounts of fetal calf serum and bFGFR1 (10-30 mg/L) to be analyzed without prior purification. The assay was linear for added receptor in the range of 1-7 micrograms.