Crystallization studies of glycosylated and unglycosylated human recombinant interleukin-2

✍ Scribed by Enrico A. Stura; Ping Chen; Carrie M. Wilmot; Jairo H. Arevalo; Ian A. Wilson

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 603 KB
• Volume: 12
• Category: Article
• ISSN: 0887-3585
• DOI: 10.1002/prot.340120104

✦ Synopsis

Abstract

Glycosylated interleukin‐2 (glyIL‐2) has been crystallized in two crystal forms, and unglycosylated interleukin‐2 (uIL‐2) has been crystallized in three forms. The glycosylated form of the human recombinant IL‐2 has been crystallized from 1.9 M ammonium sulfate, pH 6.5 to 7.0 in the hexagonal space group __P__6~2~22 or its enantiomorph. The crystals diffract to 2.8 Å and contain two or three molecules per asymmetric unit. A second crystal form grows from 1.4 to 1.5 M ammonium sulfate in 0.2 M ammonium acetate, pH 5.0–5.5, as polycrystalline rosettes which are not suitable for even a preliminary crystallographic analysis. The uIL‐2 crystallizes from 1.0 to 1.7 M ammonium sulfate, 0.2 M ammonium acetate, pH 4.5–5.6 in the monoclinic space group __P__2~1~, and less frequently in the orthorhombic space group __P__2~1~2~1~2~1~ from 2.5 M ammonium sulfate, pH 4.5 to 5.7. Cross‐seeding uIL‐2 with seeds from hexagonal crystals of glyIL‐2 promotes nucleation of trigonal crystals of unglycosylated IL‐2. These trigonal crystals belong to the space group __P__3~1~21 or its enantiomorph, with similar cell dimensions to the glyIL‐2 hexagonal crystals.