5E7W

X-ray Structure of Human Recombinant 2Zn insulin at 0.92 Angstrom


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.9519 Å
  • R-Value Free: 0.144 
  • R-Value Work: 0.111 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Ultra-high resolution X-ray structures of two forms of human recombinant insulin at 100 K.

Lisgarten, D.R.Palmer, R.A.Lobley, C.M.C.Naylor, C.E.Chowdhry, B.Z.Al-Kurdi, Z.I.Badwan, A.A.Howlin, B.J.Gibbons, N.C.J.Saldanha, J.W.Lisgarten, J.N.Basak, A.K.

(2017) Chem Cent J 11: 73-73

  • DOI: 10.1186/s13065-017-0296-y

  • PubMed Abstract: 
  • The crystal structure of a commercially available form of human recombinant (HR) insulin, Insugen (I), used in the treatment of diabetes has been determined to 0.92 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16,000 ...

    The crystal structure of a commercially available form of human recombinant (HR) insulin, Insugen (I), used in the treatment of diabetes has been determined to 0.92 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16,000 keV (λ = 0.77 Å). Refinement carried out with anisotropic displacement parameters, removal of main-chain stereochemical restraints, inclusion of H atoms in calculated positions, and 220 water molecules, converged to a final value of R = 0.1112 and Rfree = 0.1466. The structure includes what is thought to be an ordered propanol molecule (POL) only in chain D(4) and a solvated acetate molecule (ACT) coordinated to the Zn atom only in chain B(2). Possible origins and consequences of the propanol and acetate molecules are discussed. Three types of amino acid representation in the electron density are examined in detail: (i) sharp with very clearly resolved features; (ii) well resolved but clearly divided into two conformations which are well behaved in the refinement, both having high quality geometry; (iii) poor density and difficult or impossible to model. An example of type (ii) is observed for the intra-chain disulphide bridge in chain C(3) between Sγ6-Sγ11 which has two clear conformations with relative refined occupancies of 0.8 and 0.2, respectively. In contrast the corresponding S-S bridge in chain A(1) shows one clearly defined conformation. A molecular dynamics study has provided a rational explanation of this difference between chains A and C. More generally, differences in the electron density features between corresponding residues in chains A and C and chains B and D is a common observation in the Insugen (I) structure and these effects are discussed in detail. The crystal structure, also at 0.92 Å and 100 K, of a second commercially available form of human recombinant insulin, Intergen (II), deposited in the Protein Data Bank as 3W7Y which remains otherwise unpublished is compared here with the Insugen (I) structure. In the Intergen (II) structure there is no solvated propanol or acetate molecule. The electron density of Intergen (II), however, does also exhibit the three types of amino acid representations as in Insugen (I). These effects do not necessarily correspond between chains A and C or chains B and D in Intergen (II), or between corresponding residues in Insugen (I). The results of this comparison are reported. Graphical abstract Conformations of PheB25 and PheD25 in three insulin structures: implications for biological activity? Insulin residues PheB25 and PheD25 are considered to be important for insulin receptor binding and changes in biological activity occur when these residues are modified. In porcine insulin and Intergen (II) PheB25 adopts conformation B and PheD25 conformation D. However, unexpectedly PheB25 in Insugen (I) human recombinant insulin adopts two distinct conformations corresponding to B and D, Figure 1 and PheD25 adopts a single conformation corresponding to B not D, Figure 2. Conformations of this residue in the ultra-high resolution structure of Insugen (I) are therefore unique within this set. Figures were produced with Biovia, Discovery Studio 2016.


    Organizational Affiliation

    Biomolecular Research Group, School of Human and Life Sciences, Canterbury Christ Church University, North Holmes Road, Canterbury, Kent, CT1 1QU, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Insulin
A, C
21Homo sapiensMutation(s): 0 
Gene Names: INS
Find proteins for P01308 (Homo sapiens)
Go to Gene View: INS
Go to UniProtKB:  P01308
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Insulin
B, D
30Homo sapiensMutation(s): 0 
Gene Names: INS
Find proteins for P01308 (Homo sapiens)
Go to Gene View: INS
Go to UniProtKB:  P01308
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
POL
Query on POL

Download SDF File 
Download CCD File 
D
N-PROPANOL
1-PROPONOL
C3 H8 O
BDERNNFJNOPAEC-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

Download SDF File 
Download CCD File 
B, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.9519 Å
  • R-Value Free: 0.144 
  • R-Value Work: 0.111 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 81.820α = 90.00
b = 81.820β = 90.00
c = 33.850γ = 120.00
Software Package:
Software NamePurpose
SHELXLrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-10-12
    Type: Initial release
  • Version 1.1: 2017-11-15
    Type: Database references
  • Version 1.2: 2017-12-06
    Type: Database references