1IGL

SOLUTION STRUCTURE OF HUMAN INSULIN-LIKE GROWTH FACTOR II RELATIONSHIP TO RECEPTOR AND BINDING PROTEIN INTERACTIONS

Summary for 1IGL

• Entry DOI: 10.2210/pdb1igl/pdb
• Descriptor: INSULIN-LIKE GROWTH FACTOR II (1 entity in total)
• Functional Keywords: growth factor
• Biological source: Homo sapiens (human)
• Cellular location: Secreted : P01344
• Total number of polymer chains: 1
• Total formula weight: 7484.47

Authors

Torres, A.M.,Forbes, B.E.,Aplin, S.E.,Wallace, J.C.,Francis, G.L.,Norton, R.S. (deposition date: 1994-12-29, release date: 1995-02-14, Last modification date: 2024-10-30)

Primary citation

Torres, A.M.,Forbes, B.E.,Aplin, S.E.,Wallace, J.C.,Francis, G.L.,Norton, R.S.
Solution structure of human insulin-like growth factor II. Relationship to receptor and binding protein interactions.
J.Mol.Biol., 248:385-401, 1995

PubMed Abstract: The three-dimensional structure of human insulin-like growth factor (IGF) II in aqueous solution at pH 3.1 and 300 K has been determined from nuclear magnetic resonance data and restrained molecular dynamics calculations. Structural constraints consisting of 502 NOE-derived distance constraints, 11 dihedral angle restraints, and three disulfide bridges were used as input for distance geometry calculations in DIANA and X-PLOR, followed by simulated annealing refinement and energy minimization in X-PLOR. The resulting family of 20 structures was well defined in the regions of residues 5 to 28 and 41 to 62, with an average pairwise root-mean-square deviation of 1.24 A for the backbone heavy-atoms (N, C2, C) and 1.90 A for all heavy atoms. The poorly defined regions consist of the N and C termini, part of the B-domain, and the C-domain loop. Resonances from these regions of the protein gave stronger cross peaks in two dimensional NMR spectra, consistent with significant motional averaging. The main secondary structure elements in IGF-II are alpha-helices encompassing residues 11 to 21, 42 to 49 and 53 to 59. A small anti-parallel beta-sheet is formed by residues 59 to 61 and 25 to 27, while residues 26 to 28 appear to participate in intermolecular beta-sheet formation. The structure of IGF-II in the well-defined regions is very similar to those of the corresponding regions of insulin and IGF-I. Significant differences between IGF-II and IGF-I occur near the start of the third helix, in a region known to modulate affinity for the type 2 IGF receptor, and at the C terminus. The IGF II structure is discussed in relation to its binding sites for the insulin and IGF receptors and the IGF binding proteins.

PubMed: 7739048

Experimental method

SOLUTION NMR