title: Resonance assignments for Oncostatin M, a 24-kDa alpha-helical protein.
abstract: Oncostatin M (OM) is a cytokine that shares a structural and functional relationship with interleukin-6, leukemia inhibitory factor, and granulocyte-colony stimulating factor, which regulate the proliferation and differentiation of a variety of cell types. A mutant version of human OM in which two N-linked glycosylation sites and an unpaired cysteine have been mutated to alanine (N76A/C81A/N193A) has been expressed and shown to be active. The triple mutant has been doubly isotope-labeled with 13C and 15N in order to utilize heteronuclear multidimensional NMR techniques for structure determination. Approximately 90% of the backbone resonances were assigned from a combination of triple-resonance data (HNCA, HNCO, CBCACONH, HBHACONH, HNHA and HCACO), intraresidue and sequential NOEs (3D 15N-NOESY-HMQC and 13C-HSQC-NOESY) and side-chain information obtained from the CCONH and HCCONH experiments. Preliminary analysis of the NOE pattern in the 15N-NOESY-HMQC spectrum and the 13C alpha secondary chemical shifts predicts a secondary structure for OM consisting of four alpha-helices with three intervening helical regions, consistent with the four-helix-bundle motif found for this cytokine family. As a 203-residue protein with a molecular weight of 24 kDa, Oncostatin M is the largest alpha-helical protein yet assigned.
authors.affiliation: Immunex Corp., Seattle, WA 98101, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Hoffman
authors.forename: F J
authors.initials: FJ
authors.lastname: Moy
authors.forename: V
authors.initials: V
authors.lastname: Price
authors.forename: J
authors.initials: J
authors.lastname: Richardson
authors.forename: D
authors.initials: D
authors.lastname: Kaubisch
authors.forename: E A
authors.initials: EA
authors.lastname: Frieden
authors.forename: J D
authors.initials: JD
authors.lastname: Krakover
authors.forename: B J
authors.initials: BJ
authors.lastname: Castner
authors.forename: J
authors.initials: J
authors.lastname: King
authors.forename: C J
authors.initials: CJ
authors.lastname: March
authors.forename: R
authors.initials: R
authors.lastname: Powers
mesh_terms: D000595:Amino Acid Sequence; D016207:Cytokines / Q000737:chemistry* / Q000235:genetics; D006031:Glycosylation; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation; D053683:Oncostatin M; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary
chemical_list: D016207:Cytokines; C508351:OSM protein, human; D010455:Peptides; D053683:Oncostatin M