Expression, purification, crystallization and preliminary X-ray analysis of a truncated soluble domain of human glioma pathogenesis-related protein 1

Abstract

Glioma pathogenesis-related protein 1 (GLIPR1) is a member of the CAP superfamily that includes proteins from a wide range of eukaryotic organisms. The biological functions of most CAP proteins, including GLIPR1, are unclear. GLIPR1 is up-regulated in aggressive glioblastomas and contributes to the invasiveness of cultured glioblastoma cells. In contrast, decreased GLIPR1 expression is associated with advanced prostate cancer. Forced GLIPR1 overexpression is pro-apoptotic in prostate cancer cells and is being tested in clinical trials as an experimental prostate-cancer therapy. Human GLIPR1 was expressed as a truncated soluble protein (sGLIPR1), purified and crystallized. Useful X-ray data have been collected to beyond 1.9 Å resolution from a crystal that belonged to the orthorhombic space group P2(1)2(1)2 with average unit-cell parameters a = 85.1, b = 79.5, c = 38.9 Å and either a monomer or dimer in the asymmetric unit.

Figure 1

The largest sGLIPR1 crystal is 0.5 mm on the longest side and 0.1 mm on the smallest side and was separated with cryotools prior to cryocooling in a stream of liquid N₂ for data collection.

Figure 2

The crystal has visible diffraction spots beyond 2.0 Å resolution and the diffraction pattern indicates that the crystal is of a protein and not a salt.