PDBsum entry 1sjt

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protein Protein-protein interface(s) links
Hormone PDB id
Protein chains
21 a.a.
29 a.a.
PDB id:
Name: Hormone
Title: Mini-proinsulin, two chain insulin analog mutant: des b30, his(b 10)asp, pro(b 28)asp, nmr, 20 structures
Structure: Proinsulin. Chain: a. Engineered: yes. Mutation: yes. Proinsulin. Chain: b. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Organ: pancreas. Organ: pancreas
NMR struc: 20 models
Authors: Q.X.Hua,S.Q.Hu,W.H.Jia,Y.C.Chu,G.T.Burke,S.H.Wang, P.G.Katsoyannis,M.A.Weiss
Key ref:
Q.X.Hua et al. (1998). Mini-proinsulin and mini-IGF-I: homologous protein sequences encoding non-homologous structures. J Mol Biol, 277, 103-118. PubMed id: 9514738 DOI: 10.1006/jmbi.1997.1574
09-Oct-97     Release date:   18-Mar-98    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P01308  (INS_HUMAN) -  Insulin
110 a.a.
21 a.a.
Protein chain
Pfam   ArchSchema ?
P01308  (INS_HUMAN) -  Insulin
110 a.a.
29 a.a.*
Key:    PfamA domain  Secondary structure
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     extracellular region   1 term 
  Biochemical function     hormone activity     1 term  


DOI no: 10.1006/jmbi.1997.1574 J Mol Biol 277:103-118 (1998)
PubMed id: 9514738  
Mini-proinsulin and mini-IGF-I: homologous protein sequences encoding non-homologous structures.
Q.X.Hua, S.Q.Hu, W.Jia, Y.C.Chu, G.T.Burke, S.H.Wang, R.Y.Wang, P.G.Katsoyannis, M.A.Weiss.
Protein minimization highlights essential determinants of structure and function. Minimal models of proinsulin and insulin-like growth factor I contain homologous A and B domains as single-chain analogues. Such models (designated mini-proinsulin and mini-IGF-I) have attracted wide interest due to their native foldability but complete absence of biological activity. The crystal structure of mini-proinsulin, determined as a T3R3 hexamer, is similar to that of the native insulin hexamer. Here, we describe the solution structure of a monomeric mini-proinsulin under physiologic conditions and compare this structure to that of the corresponding two-chain analogue. The two proteins each contain substitutions in the B-chain (HisB10-->Asp and ProB28-->Asp) designed to destabilize self-association by electrostatic repulsion; the proteins differ by the presence or absence of a peptide bond between LysB29 and GlyA1. The structures are essentially identical, resembling in each case the T-state crystallographic protomer. Differences are observed near the site of cross-linking: the adjoining A1-A8 alpha-helix (variable among crystal structures) is less well-ordered in mini-proinsulin than in the two-chain variant. The single-chain analogue is not completely inactive: its affinity for the insulin receptor is 1500-fold lower than that of the two-chain analogue. Moreover, at saturating concentrations mini-proinsulin retains the ability to stimulate lipogenesis in adipocytes (native biological potency). These results suggest that a change in the conformation of insulin, as tethered by the B29-A1 peptide bond, optimizes affinity but is not integral to the mechanism of transmembrane signaling. Surprisingly, the tertiary structure of mini-proinsulin differs from that of mini-IGF-I (main-chain rms deviation 4.5 A) despite strict conservation of non-polar residues in their respective hydrophobic cores (side-chain rms deviation 4.9 A). Three-dimensional profile scores suggest that the two structures each provide acceptable templates for threading of insulin-like sequences. Mini-proinsulin and mini-IGF-I thus provide examples of homologous protein sequences encoding non-homologous structures.
  Selected figure(s)  
Figure 2.
Figure 2. A, T-state protomer of mini-proinsulin in the crystallographic hexamer [Derewenda et al 1991]. The asterisk indicates the position of the peptide cross-link in mini-proinsulin connecting B29 and A1. The side-chains of Ile^A2(red), Leu^B15(blue), Phe^B24(green), Tyr^B26(white) and Tyr^A19(yellow) are shown. B, Structure of mini-IGF-I [DeWolf et al 1996] in a similar orientation. The asterisk indicates the peptide bond between the A and B domains. Homologous side-chains are shown in corresponding colors as for A. C, Stereo pair showing relative displacement of the conserved side-chains in the hydrophobic cores of mini-proinsulin and mini-IGF-I. The numbering scheme at the left refers to the mini-IGF-I sequence. Leu14 in IGF-I corresponds to Leu^B15in mini-proinsulin; Phe23 in mini-IGF-I corresponds to PheB24 in mini-proinsulin, etc. The orientation is the same as in A and B.
Figure 4.
Figure 4. One-dimensional^1H-NMR spectra of A, the two-chain insulin analogue and B, the monomeric mini-proinsulin at p^2H 7.4 (direct meter reading) and 25°C. Selected resonances are labeled in A: C[2]H of His^B5, meta resonance of Tyr^B26, and δ-CH[3]resonance of Leu^B15. In B the arrow indicates corresponding up-field methyl resonance of Leu^B15; the asterisk indicates an impurity; T indicates resonance of Tris-HCl.
  The above figures are reprinted by permission from Elsevier: J Mol Biol (1998, 277, 103-118) copyright 1998.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
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
18793116 A.Abbas, P.J.Grant, and M.T.Kearney (2008).
Role of IGF-1 in glucose regulation and cardiovascular disease.
  Expert Rev Cardiovasc Ther, 6, 1135-1149.  
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.  
18332129 Q.X.Hua, S.H.Nakagawa, W.Jia, K.Huang, N.B.Phillips, S.Q.Hu, and M.A.Weiss (2008).
Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications.
  J Biol Chem, 283, 14703-14716.
PDB codes: 2jzq 3bxq
17906644 D.R.Clemmons (2007).
Modifying IGF1 activity: an approach to treat endocrine disorders, atherosclerosis and cancer.
  Nat Rev Drug Discov, 6, 821-833.  
17884811 K.Huang, S.J.Chan, Q.X.Hua, Y.C.Chu, R.Y.Wang, B.Klaproth, W.Jia, J.Whittaker, P.De Meyts, S.H.Nakagawa, D.F.Steiner, P.G.Katsoyannis, and M.A.Weiss (2007).
The A-chain of insulin contacts the insert domain of the insulin receptor. Photo-cross-linking and mutagenesis of a diabetes-related crevice.
  J Biol Chem, 282, 35337-35349.
PDB codes: 2jum 2juu 2juv
17716170 M.Koch, F.F.Schmid, V.Zoete, and M.Meuwly (2006).
Insulin: a model system for nanomedicine?
  Nanomed, 1, 373-378.  
16751187 S.H.Nakagawa, Q.X.Hua, S.Q.Hu, W.Jia, S.Wang, P.G.Katsoyannis, and M.A.Weiss (2006).
Chiral mutagenesis of insulin. Contribution of the B20-B23 beta-turn to activity and stability.
  J Biol Chem, 281, 22386-22396.  
16239223 K.Huang, J.Dong, N.B.Phillips, P.R.Carey, and M.A.Weiss (2005).
Proinsulin is refractory to protein fibrillation: topological protection of a precursor protein from cross-beta assembly.
  J Biol Chem, 280, 42345-42355.  
16080143 V.Zoete, M.Meuwly, and M.Karplus (2005).
Study of the insulin dimerization: binding free energy calculations and per-residue free energy decomposition.
  Proteins, 61, 79-93.  
16215634 Z.Y.Guo, Z.Zhang, X.Y.Jia, Y.H.Tang, and Y.M.Feng (2005).
Mutational analysis of the absolutely conserved B8Gly: consequence on foldability and activity of insulin.
  Acta Biochim Biophys Sin (Shanghai), 37, 673-679.  
15653430 Z.Y.Guo, X.Y.Jia, and Y.M.Feng (2004).
Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin.
  Biol Chem, 385, 1171-1175.  
12446709 B.Y.Zhang, M.Liu, and P.Arvan (2003).
Behavior in the eukaryotic secretory pathway of insulin-containing fusion proteins and single-chain insulins bearing various B-chain mutations.
  J Biol Chem, 278, 3687-3693.  
12649435 H.Yan, Z.Y.Guo, X.W.Gong, D.Xi, and Y.M.Feng (2003).
A peptide model of insulin folding intermediate with one disulfide.
  Protein Sci, 12, 768-775.  
12590147 M.Liu, J.Ramos-Castañeda, and P.Arvan (2003).
Role of the connecting peptide in insulin biosynthesis.
  J Biol Chem, 278, 14798-14805.  
12796500 M.T.Nguyen, J.Beck, H.Lue, H.Fünfzig, R.Kleemann, P.Koolwijk, A.Kapurniotu, and J.Bernhagen (2003).
A 16-residue peptide fragment of macrophage migration inhibitory factor, MIF-(50-65), exhibits redox activity and has MIF-like biological functions.
  J Biol Chem, 278, 33654-33671.  
12654724 Q.X.Hua, S.H.Nakagawa, J.Wilken, R.R.Ramos, W.Jia, J.Bass, and M.A.Weiss (2003).
A divergent INS protein in Caenorhabditis elegans structurally resembles human insulin and activates the human insulin receptor.
  Genes Dev, 17, 826-831.  
14573855 X.Y.Jia, Z.Y.Guo, Y.Wang, Y.Xu, S.S.Duan, and Y.M.Feng (2003).
Peptide models of four possible insulin folding intermediates with two disulfides.
  Protein Sci, 12, 2412-2419.  
12817477 Z.Y.Guo, Y.H.Tang, S.Wang, and Y.M.Feng (2003).
Contribution of the absolutely conserved B8Gly to the foldability of insulin.
  Biol Chem, 384, 805-809.  
11814349 Z.Y.Guo, L.Shen, and Y.M.Feng (2002).
The different folding behavior of insulin and insulin-like growth factor 1 is mainly controlled by their B-chain/domain.
  Biochemistry, 41, 1556-1567.  
12186542 Z.Y.Guo, L.Shen, and Y.M.Feng (2002).
The different energetic state of the intra A-chain/domain disulfide of insulin and insulin-like growth factor 1 is mainly controlled by their B-chain/domain.
  Biochemistry, 41, 10585-10592.  
11402063 B.Zhang, A.Chang, T.B.Kjeldsen, and P.Arvan (2001).
Intracellular retention of newly synthesized insulin in yeast is caused by endoproteolytic processing in the Golgi complex.
  J Cell Biol, 153, 1187-1198.  
10744677 L.G.Laajoki, G.L.Francis, J.C.Wallace, J.A.Carver, and M.A.Keniry (2000).
Solution structure and backbone dynamics of long-[Arg(3)]insulin-like growth factor-I.
  J Biol Chem, 275, 10009-10015.
PDB code: 3lri
11106430 R.Kleemann, H.Rorsman, E.Rosengren, R.Mischke, N.T.Mai, and J.Bernhagen (2000).
Dissection of the enzymatic and immunologic functions of macrophage migration inhibitory factor. Full immunologic activity of N-terminally truncated mutants.
  Eur J Biochem, 267, 7183-7193.  
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 codes are shown on the right.