title: Structural change and receptor binding in a chemokine mutant with a rearranged disulfide: X-ray structure of E38C/C50AIL-8 at 2 A resolution.
abstract: The characteristic CXC chemokine disulfide core of interleukin-8 (IL-8) has been rearranged in a variant replacing the 9-50 disulfide with a 9-38 disulfide. The new variant has been characterized by its binding affinity to IL-8 receptors A and B and the erythrocyte receptor DARC. This variant binds the three receptors with affinities between 500- and 2,500-fold lower than wild-type IL-8. Binding affinity results are also reported for the variant with alanine substituted for both cysteines 9 and 50. The Glu38-->Cys/Cys50-->Ala IL-8 crystallizes in space group P2(1)2(1)2(1) with cell parameters a = 46.4, b = 49.2, and c = 69.5 A, and has been refined to an R-value of 19.4% for data from 10 to 2 A resolution. Analysis of the structure confirms the new disulfide arrangement and suggests that changes at Ile10 may be the principal cause of the lowered affinities.
authors.affiliation: Department of Protein Engineering, Genentech, Inc., South San Francisco, California 94080-4990, USA.
authors.forename: C
authors.initials: C
authors.lastname: Eigenbrot
authors.forename: H B
authors.initials: HB
authors.lastname: Lowman
authors.forename: L
authors.initials: L
authors.lastname: Chee
authors.forename: D R
authors.initials: DR
authors.lastname: Artis
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000235:genetics*; D004220:Disulfides / Q000737:chemistry*; D004912:Erythrocytes / Q000378:metabolism; D016209:Interleukin-8 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D009504:Neutrophils / Q000378:metabolism; D011487:Protein Conformation; D018123:Receptors, Interleukin / Q000378:metabolism*; D023062:Receptors, Interleukin-8A; D014867:Water / Q000737:chemistry
chemical_list: D015703:Antigens, CD; D004220:Disulfides; D016209:Interleukin-8; D018123:Receptors, Interleukin; D023062:Receptors, Interleukin-8A; D014867:Water; D003545:Cysteine