spacer
spacer

PDBsum entry 1b18

Go to PDB code: 
protein ligands Protein-protein interface(s) links
Hormone/growth factor PDB id
1b18
Jmol PyMol
Contents
Protein chains
21 a.a.
30 a.a. *
Ligands
SO4
Waters ×64
* Residue conservation analysis
PDB id:
1b18
Name: Hormone/growth factor
Title: Ph affects glu b13 switching and sulfate binding in cubic insulin crystals (ph 5.53 coordinates)
Structure: Protein (insulin a chain). Chain: a. Protein (insulin b chain). Chain: b
Source: Sus scrofa. Pig. Organism_taxid: 9823. Organ: pancreas. Organ: pancreas
Biol. unit: Dimer (from PQS)
Resolution:
1.80Å     R-factor:   0.183     R-free:   0.216
Authors: J.S.Diao,D.L.D.Caspar
Key ref:
J.Diao (2003). Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding. Acta Crystallogr D Biol Crystallogr, 59, 670-676. PubMed id: 12657786 DOI: 10.1107/S0907444903002208
Date:
26-Nov-98     Release date:   08-Apr-03    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
P01315  (INS_PIG) -  Insulin
Seq:
Struc:
108 a.a.
21 a.a.
Protein chain
Pfam   ArchSchema ?
P01315  (INS_PIG) -  Insulin
Seq:
Struc:
108 a.a.
30 a.a.
Key:    PfamA domain  Secondary structure

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

 

 
DOI no: 10.1107/S0907444903002208 Acta Crystallogr D Biol Crystallogr 59:670-676 (2003)
PubMed id: 12657786  
 
 
Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding.
J.Diao.
 
  ABSTRACT  
 
Structures of porcine insulin crystals soaked in 1 M sodium sulfate at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00 have been determined at between 1.7 and 1.9 A resolution. GluB13 exhibits a single conformation at pH </= 5.80, two conformations between pH 6.00 and 6.98 and a single conformation at pH 9.00. Between pH 6.00 and 6.98, the conformation of GluB13 switches from one rotamer to another rotamer. Between pH 6.16 and 6.26, PheB1 undergoes a significant conformational change. By pH 9.00 many residues have undergone relatively large shifts and HisB10 exhibits a double conformation. As a result of the pH increase, the occupancy of the sulfate ion decreases from a maximum of 1.00 at pH 5.00 to a minimum of 0.46 at pH 6.50. Comparison of the structures, the observed and calculated structure factors and map correlation coefficients indicate that the porcine insulin structure changes gradually as a function of pH.
 
  Selected figure(s)  
 
Figure 2.
Figure 2 Structures at ten different pH and corresponding 2F[o] - F[c] maps. Structures in the region of GluB13 and the sulfate ion are presented and 2F[o] - F[c] maps are contoured at the 0.8 level because of the approximate half-occupancy of the two rotamers of GluB13 and the lower electron density compared with the rest of the structure. Sub-figures correspond to the structures at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00, respectively.
Figure 4.
Figure 4 Sulfate-binding region. The coordinates at pH 5.00 were used to produce the figure.
 
  The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2003, 59, 670-676) copyright 2003.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
18156668 N.Niimura, and R.Bau (2008).
Neutron protein crystallography: beyond the folding structure of biological macromolecules.
  Acta Crystallogr A, 64, 12-22.  
17899393 L.Wang, H.R.Eghbalnia, and J.L.Markley (2007).
Nearest-neighbor effects on backbone alpha and beta carbon chemical shifts in proteins.
  J Biomol NMR, 39, 247-257.  
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.

 

spacer

spacer