Biological Assembly 1  

 3D View: Structure

Standalone Viewers  
Protein Workshop | Ligand Explorer

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 19271.15 
• Atom Count: 1352 
• Residue Count: 176 
• Unique protein chains: 2

1CWB

THE X-RAY STRUCTURE OF (MEBM2T)1-CYCLOSPORIN COMPLEXED WITH CYCLOPHILIN A PROVIDES AN EXPLANATION FOR ITS ANOMALOUSLY HIGH IMMUNOSUPPRESSIVE ACTIVITY

• DOI: 10.2210/pdb1CWB/pdb

• Classification: ISOMERASE/IMMUNOSUPPRESSANT
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): 1 


• Deposited: 1995-09-06 Released: 1996-01-29 
• Deposition Author(s): Mikol, V., Kallen, J., Walkinshaw, M.D.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.2 Å
• R-Value Work: 0.162 

Literature

The X-Ray Structure of (Mebm2T)1-Cyclosporin Complexed with Cyclophilin a Provides an Explanation for its Anomalously High Immunosuppressive Activity.

Mikol, V., Kallen, J., Walkinshaw, M.D.

(1994) Protein Eng. 7: 597

• PubMed: 8073029 
• Also Cited By: 1CWC, 1CWA


• PubMed Abstract: 
  

For most of the cyclosporin A (CsA) analogs, there is generally a good correlation between cyclophilin binding and immunosuppression. However, this relationship does not seem to hold for 4-[(E)-2-butenyl]-4,4,N-trimethyl-L-threonine1 (MeBm2t)1-CsA. Its affinity for cyclophilin was reported to be approximately 1% that of CsA and its immunosuppressive activity in vitro was shown to be approximately 30% that of CsA. We report here the crystal structure of a complex between recombinant human cyclophilin A (CypA) and (MeBm2t)1-CsA which has been determined by X-ray crystallography at 2.2 A resolution and refined to an R-factor of 16.3%. (MeBm2t)1-CsA shows a similar bound conformation and network of interactions to CypA as CsA. The measured lower affinity for CypA cannot therefore be explained by a different mode of binding. We propose that the poor affinity to CypA could be accounted for by the existence of an equilibrium in aqueous solution between a 'cyclophilin bound conformation' and a 'non-binding conformation' of (MeBm2t)1-CsA. The relatively high immunosuppressive activity is suggested to result from slight conformational differences observed in the effector domain.

---

Related Citations: 

• Improved Binding Affinity for Cyclophilin a by a Cyclosporin Derivative Singly Modified at its Effector Domain.
  Papageorgiou, C.,Florineth, A.,Mikol, V.
  (1994) J.Med.Chem. 37: 3674
• Crystallization of the Complex between Cyclophilin a and Cyclosporin Derivatives: The Use of Cross- Seeding.
  Mikol, V.,Duc, D.
  (1994) Acta Crystallogr.,Sect.D 50: 543
• X-Ray Structure of a Monomeric Cyclophilin A- Cyclosporin a Crystal Complex at 2.1 A Resolution.
  Mikol, V.,Kallen, J.,Pflugl, G.,Walkinshaw, M.D.
  (1993) J.Mol.Biol. 234: 1119
• X-Ray Structure of a Decameric Cyclophilin- Cyclosporin Crystal Complex.
  Pflugl, G.,Kallen, J.,Schirmer, T.,Jansonius, J.N.,Zurini, M.G.,Walkinshaw, M.D.
  (1993) Nature 361: 91




---

Organizational Affiliation: 

Sandoz AG, Basle, Switzerland.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
PEPTIDYL-PROLYL CIS-TRANS ISOMERASE A	A	165	Homo sapiens	Mutation(s): 0  Gene Names: PPIA (CYPA) EC: 5.2.1.8
Find proteins for P62937 (Homo sapiens) Go to Gene View: PPIA Go to UniProtKB:  P62937

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
CYCLOSPORIN A	C	11	N/A	Mutation(s): 1
Protein Feature View is not available: No corresponding UniProt sequence found.

Small Molecules

Biologically Interesting Molecules 1 Unique
ID	Chains	Name	Type/Class	2D Diagram	3D Interactions
PRD_000765	C	CYCLOSPORIN A, 5 mutation	Cyclic peptide / Immunosuppressant		--

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.2 Å
• R-Value Work: 0.162 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 36.869	α = 90.00
b = 61.292	β = 90.00
c = 71.993	γ = 90.00

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1995-09-06 
• Released Date: 1996-01-29 
• Deposition Author(s): Mikol, V., Kallen, J., Walkinshaw, M.D.

Revision History 

• Version 1.0: 1996-01-29
  Type: Initial release
• Version 1.1: 2011-06-14
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance
• Version 1.3: 2011-07-27
  Type: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary
• Version 1.4: 2012-12-12
  Type: Other