Crystallization of prostatic binding protein

Prostatic binding protein is a dimeric glycoprotein capable of binding a variety of steroids. This protein is a major component of rat prostate cytosol making it possible to purify milligram quantities. Hexagonal crystals of X-ray diffraction quality have been grown from phosphate buffered ammonium sulfate solution by vapor diffusion methods. These crystals which are reasonably stable to X-rays, show diffraction to 6.3 Å and belong to space group P6₁ or P6₁22 or the enantiomorphs. The unit cell has dimensions a = 88.7(5) Å, c = 405(2) Å, contains 24 molecules and has a specific volume of 2.8 ų/Dalton.