Crystallization and preliminary X-ray diffraction analysis of Jun a 1, the major allergen isolated from pollen of the mountain cedar Juniperus ashei

Jun a 1, the major allergen of pollen from the mountain cedar Juniperus ashei, has been crystallized using the hanging-drop vapor-diffusion method at 277 K. The crystals are monoclinic, space group P2₁, with unit-cell parameters a = 53.38, b = 113.48, c = 72.44 Å, β = 96.36° and four molecules in the unit cell. A complete 2.5 Å data set has been collected at 100 K with X-rays from a Cu Kα rotatinganode generator.