Recombinant rat fibroblast growth factor-16: structure and biological activity

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Chemistry

Background:

• Fibroblast growth factor-16 (FGF-16) is a recently identified member of the FGF family.
• The biological activity and structural characteristics of rat FGF-16 (rFGF-16) were previously unknown.
• rFGF-16 lacks an apparent signal sequence, necessitating expression in a heterologous system for study.

Purpose of the Study:

• To achieve high-level expression and characterize the novel protein, rat FGF-16 (rFGF-16).
• To investigate and overcome purification challenges associated with rFGF-16.
• To elucidate the structural and biological properties of a truncated form, d34 rFGF-16.

Main Methods:

• Expression of full-length and truncated rFGF-16 in Escherichia coli.
• Purification using sequential cation-exchange chromatography, with EDTA inclusion to prevent precipitation.
• Structural characterization via circular dichroism, Fourier transform infrared spectroscopy, and sedimentation velocity analysis.
• In vitro and in vivo biological assays to assess proliferative effects.

Main Results:

• Initial attempts to purify full-length rFGF-16 resulted in significant precipitation and N-terminal truncations.
• A truncated form, d34 rFGF-16, was successfully expressed and purified by including EDTA during the process.
• Structural analysis revealed d34 rFGF-16 possesses a distinct tertiary structure, rich in beta-strands.
• Biologic assays demonstrated that d34 rFGF-16 induces oligodendrocyte proliferation in vitro and hepatocellular proliferation in vivo.

Conclusions:

• FGF-16 exhibits unique structural and biological properties distinct from other FGF family members.
• The truncated d34 rFGF-16 form can be purified and retains significant biological activity.
• FGF-16 plays a role in promoting cell proliferation in both neural and hepatic systems.