PDBsum entry 3bxq

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protein metals Protein-protein interface(s) links
Hormone PDB id
Protein chains
21 a.a.
30 a.a. *
_ZN ×2
Waters ×127
* Residue conservation analysis
PDB id:
Name: Hormone
Title: The structure of a mutant insulin uncouples receptor binding from protein allostery. An electrostatic block to the tr transition
Structure: Insulin a chain. Chain: a, c. Engineered: yes. Insulin b chain. Chain: b, d. Engineered: yes. Mutation: yes
Source: Synthetic: yes. Synthetic: yes
1.30Å     R-factor:   0.206     R-free:   0.232
Authors: Z.L.Wan,K.Huang,S.Q.Hu,J.Whittaker,M.A.Weiss
Key ref:
Q.X.Hua et al. (2008). Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications. J Biol Chem, 283, 14703-14716. PubMed id: 18332129 DOI: 10.1074/jbc.M800313200
14-Jan-08     Release date:   20-May-08    
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Protein chains
Pfam   ArchSchema ?
P01308  (INS_HUMAN) -  Insulin
110 a.a.
21 a.a.
Protein chains
Pfam   ArchSchema ?
P01308  (INS_HUMAN) -  Insulin
110 a.a.
30 a.a.*
Key:    PfamA domain  Secondary structure
* PDB and UniProt seqs differ at 1 residue position (black cross)


DOI no: 10.1074/jbc.M800313200 J Biol Chem 283:14703-14716 (2008)
PubMed id: 18332129  
Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications.
Q.X.Hua, S.H.Nakagawa, W.Jia, K.Huang, N.B.Phillips, S.Q.Hu, M.A.Weiss.
Single-chain insulin (SCI) analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain insulin analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 +/- 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (DeltaDeltaG(u) = 0.7 +/- 0.1 kcal/mol relative to the corresponding two-chain analog and 1.9 +/- 0.1 kcal/mol relative to wild-type insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the insulin moiety: its central Pro contacts Val(A3) at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 alpha-helix. Comparison between SCI-57 and its parent two-chain analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of insulin replacement therapy in the developing world.
  Selected figure(s)  
Figure 3.
FIGURE 3. IR binding assay. Representative displacement data illustrate the activity of the present single-chain analog with a 6-residue linker (SCI-57; ), human insulin ( ), and PIP (an SCI-53; ). Whereas binding of SCI-53 (PIP) is reduced by >500-fold, a slight enhancement of affinity by SCI-57 is seen as a leftward shift of its displacement curve. The y axis (B/B[o]) indicates percent receptor-bound ^125I-labeled human insulin; the x axis (logarithmic scale to base 10) indicates the concentration of unlabeled competing insulin analog.
Figure 9.
FIGURE 9. Solution structure of SCI. A, ensemble of DG/restrained molecular dynamics models of SCI (Protein Data Bank code 2jzq). The A-chain is shown in red, the B-chain in blue, and the linker in gray. Structures were aligned according to the main chain atoms of A2-A7, A13-A19, and B9-B26. B, ribbon model of des-Thr^B30-SCI-50, an inactive 50-residue single-chain analog in which a peptide bond links Lys^B29 to Gly^A1 (Protein Data Bank code 1pid) (15). C and D, front and back views, respectively, of SCI-57 with selected side chains shown relative to the ribbon model of DKP-insulin (black) (Protein Data Bank code 2jmn) (7). The side chain coloring scheme is as follows: Val^A3, green; Tyr^A19, green; Phe^B24, dark purple; Tyr^B26, blue; and linker residue Pro^C4, magenta.
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2008, 283, 14703-14716) copyright 2008.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
20348418 B.J.Smith, K.Huang, G.Kong, S.J.Chan, S.Nakagawa, J.G.Menting, S.Q.Hu, J.Whittaker, D.F.Steiner, P.G.Katsoyannis, C.W.Ward, M.A.Weiss, and M.C.Lawrence (2010).
Structural resolution of a tandem hormone-binding element in the insulin receptor and its implications for design of peptide agonists.
  Proc Natl Acad Sci U S A, 107, 6771-6776.
PDB code: 3loh
20669185 R.F.Sommese, S.Sivaramakrishnan, R.L.Baldwin, and J.A.Spudich (2010).
Helicity of short E-R/K peptides.
  Protein Sci, 19, 2001-2005.  
20106984 Y.Yang, A.Petkova, K.Huang, B.Xu, Q.X.Hua, I.J.Ye, Y.C.Chu, S.Q.Hu, N.B.Phillips, J.Whittaker, F.Ismail-Beigi, R.B.Mackin, P.G.Katsoyannis, R.Tycko, and M.A.Weiss (2010).
An Achilles' heel in an amyloidogenic protein and its repair: insulin fibrillation and therapeutic design.
  J Biol Chem, 285, 10806-10821.  
19274663 C.W.Ward, and M.C.Lawrence (2009).
Ligand-induced activation of the insulin receptor: a multi-step process involving structural changes in both the ligand and the receptor.
  Bioessays, 31, 422-434.  
19321436 Q.X.Hua, B.Xu, K.Huang, S.Q.Hu, S.Nakagawa, W.Jia, S.Wang, J.Whittaker, P.G.Katsoyannis, and M.A.Weiss (2009).
Enhancing the activity of a protein by stereospecific unfolding: conformational life cycle of insulin and its evolutionary origins.
  J Biol Chem, 284, 14586-14596.
PDB codes: 2k91 2k9r
19035371 A.P.Tofteng, K.J.Jensen, L.Schäffer, and T.Hoeg-Jensen (2008).
Total synthesis of desB30 insulin analogues by biomimetic folding of single-chain precursors.
  Chembiochem, 9, 2989-2996.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.