Crystallization and preliminary X-ray study of human dipeptidyl peptidase IV (DPPIV)

Human DPPIV has been expressed in the baculovirus system and purified and crystallized using the hanging-drop method. A crystal was obtained from 180 mM Gly-NaOH buffer pH 9.5 containing 18% PEG 4000 and 180 mM sodium acetate. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 118.04, b = 125.92, c = 136.84 A, and diffracts beyond 2.6 A resolution. There are two molecules per asymmetric unit, indicating a solvent content of 57.6%.