Crystallization and X-ray analysis of bovine glycolipid transfer protein

Glycolipid-transfer protein (GLTP) is a 24 kDa basic cytosolic protein that facilitates the transfer of glycolipids between bilayer membranes in vitro, but its in vivo function is unknown. Human, bovine, porcine and murine GLTPs have recently been cloned and share high sequence identity to each other. The three-dimensional structure of GLTP has not yet been solved and no structures of any proteins related to GLTP are known. Therefore, the structure of GLTP might reveal a currently unknown fold. Here, the crystallization and preliminary X-ray analysis of bovine GLTP are reported for the first time. Protein prepared by recombinant techniques using an Escherichia coli expression system has been crystallized using the vapour-diffusion method. The crystals belong to space group P2(1), with unit-cell parameters a = 55.4, b = 34.9, c = 58.5 A, alpha = gamma = 90, beta = 116 degrees. The crystals diffract to 1.6 A resolution and a 97.1% complete data set with an R(merge) of 6.7% has been collected from a single crystal at 100 K using synchrotron radiation.