3BXQ

The structure of a mutant insulin uncouples receptor binding from protein allostery. An electrostatic block to the TR transition

DOI: 10.2210/pdb3BXQ/pdb

Classification: HORMONE
Mutation(s): Yes

Deposited: 2008-01-14 Released: 2008-05-20
Deposition Author(s): Wan, Z.L., Huang, K., Hu, S.Q., Whittaker, J., Weiss, M.A.

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 1.30 Å
R-Value Free: 0.232
R-Value Work: 0.206

wwPDB Validation 3D Report Full Report

This is version 1.1 of the entry. See complete history.

Literature

Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications.

Hua, Q.X., Nakagawa, S.H., Jia, W., Huang, K., Phillips, N.B., Hu, S.Q., Weiss, M.A.

(2008) J Biol Chem 283: 14703-14716

PubMed: 18332129 Search on PubMedSearch on PubMed Central
DOI: 10.1074/jbc.M800313200
Primary Citation of Related Structures:
3BXQ, 2JZQ

PubMed Abstract:

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.

Related Citations:

The structure of 2zn pig insulin crystal at 1.5 A resolution
Baker, E.N., Blujdell, T.L., Cutfield, J.F., Cutfield, S.M., Dodson, E.J., Dodson, G.G., Hodgkin, D., Isaacs, N.W., Reynolds, C.D.
(1988) Philos Trans R Soc London,ser B 319: 369

Structure of insulin in 4-zinc insulin
Bentley, G., Dodson, E., Dodson, G., Hodgkin, D., Mercola, D.
(1976) Nature 261: 166

Phenol stabilizes more helix in a new symmetrical zinc insulin hexamer
Derewenda, U., Derewenda, Z., Dodson, E., Dodson, G., Reynold, C., Smith, G., Sparks, C., Swenson, D.
(1989) Nature 338: 594

Toward the active conformation of insulin: stereospecific modulation of a structural swith in the B chain
Hua, Q.X., Nakagawa, S., Hu, S.Q., Jia, W., Wang, S., Weiss, M.A.
(2006) J Biol Chem 281: 24900

Organizational Affiliation:

Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.

Macromolecules

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
insulin A chain	A, C	21	N/A	Mutation(s): 0
Find proteins for P01308 (Homo sapiens) Explore P01308 Go to UniProtKB: P01308
NIH Common Fund Data Resources
PHAROS P01308
Protein Feature View Expand
Reference Sequence

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
insulin B chain	B, D	30	N/A	Mutation(s): 1
Find proteins for P01308 (Homo sapiens) Explore P01308 Go to UniProtKB: P01308
NIH Common Fund Data Resources
PHAROS P01308
Protein Feature View Expand
Reference Sequence

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
ZN Query on ZN Download Ideal Coordinates CCD File SDF format, chain E [B] SDF format, chain F [D] MOL2 format, chain E [B] MOL2 format, chain F [D]	B, D	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N		Ligand Interaction