Purification, identification and preliminary crystallographic studies of an allergenic protein from Lathyrus sativus

A 24 kDa protein was purified from the seeds of Lathyrus sativus by ammonium sulfate fractionation and ion-exchange chromatography. The N-terminal amino-acid sequence showed significant homology with the 2S albumin class of seed storage proteins. The protein showed 85% sequence homology with the seed albumin of Pisum sativum within the 40 N-terminal residues. Crystals were obtained by the hanging-drop vapour-diffusion method. The crystals belonged to space group P2₁2₁2₁, with unit-cell parameters a = 43.5, b = 82.7, c = 153.4 Å.