TY - JOUR T1 - Purification, crystallization and X-ray diffraction analysis of a recombinant Fab that recognizes a human blood-group antigen. AU - Song,Shuh Chyung, AU - Xie,Kefang, AU - Czerwinski,Marcin, AU - Spitalnik,Steven L, AU - Wedekind,Joseph E, Y1 - 2004/03/23/ PY - 2004/01/15/received PY - 2004/02/06/accepted PY - 2004/3/25/pubmed PY - 2004/12/16/medline PY - 2004/3/25/entrez SP - 788 EP - 91 JF - Acta crystallographica. Section D, Biological crystallography JO - Acta Crystallogr D Biol Crystallogr VL - 60 IS - Pt 4 N2 - The NNA7 Fab fragment recognizes the human glycopeptide N blood-group antigen and has a high affinity for N-type glycophorin A (GPA). To provide insight into how antibodies recognize glycopeptide antigens, soluble Fab fragments were expressed in Escherichia coli, purified and crystallized using the hanging-drop vapor-diffusion method at 293 K. The best crystals were obtained from solutions of PEG monomethyl ether 5000 containing 4-8 mM yttrium chloride (YCl3). This rare-earth ion, which could be substituted with various lanthanides, changed the habit of crystals from multinucleated rods with a diffraction limit of 4.25 A resolution to a diamond-shaped morphology that grew as single crystals and diffracted X-rays to 1.75 A resolution. Data were collected that indicated that the crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 57.9, b = 77.1, c = 118.1 A and one Fab fragment per asymmetric unit. A molecular-replacement solution has been obtained and 86% of the molecule was fitted by use of an automated refinement procedure (ARP). SN - 0907-4449 UR - https://www.unboundmedicine.com/medline/citation/15039587/Purification_crystallization_and_X_ray_diffraction_analysis_of_a_recombinant_Fab_that_recognizes_a_human_blood_group_antigen_ DB - PRIME DP - Unbound Medicine ER -