1HA2

Human Serum Albumin Complexed With Myristic Acid and the S-(-) enantiomer of warfarin

• PDB DOI:  https://doi.org/10.2210/pdb1HA2/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Homo sapiens
• Expression System: Saccharomyces cerevisiae
• Mutation(s): No 


• Deposited: 2001-03-23 Released: 2001-06-20 
• Deposition Author(s): Petitpas, I., Bhattacharya, A.A., Curry, S.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.247 
• R-Value Work: 0.201 
• R-Value Observed: 0.201 

Literature

Crystal Structure Analysis of Warfarin Binding to Human Serum Albumin: Anatomy of Drug Site I

Petitpas, I., Bhattacharya, A.A., Twine, S., East, M., Curry, S.

(2001) J Biol Chem 276: 22804

• PubMed: 11285262 
• DOI: https://doi.org/10.1074/jbc.M100575200
• Primary Citation of Related Structures:  
  1H9Z, 1HA2


• PubMed Abstract: 
  

Human serum albumin (HSA) is an abundant transport protein found in plasma that binds a wide variety of drugs in two primary binding sites (I and II) and can have a significant impact on their pharmacokinetics. We have determined the crystal structures at 2.5 A-resolution of HSA-myristate complexed with the R-(+) and S-(-) enantiomers of warfarin, a widely used anticoagulant that binds to the protein with high affinity. The structures confirm that warfarin binds to drug site I (in subdomain IIA) in the presence of fatty acids and reveal the molecular details of the protein-drug interaction. The two enantiomers of warfarin adopt very similar conformations when bound to the protein and make many of the same specific contacts with amino acid side chains at the binding site, thus accounting for the relative lack of stereospecificity of the HSA-warfarin interaction. The conformation of the warfarin binding pocket is significantly altered upon binding of fatty acids, and this can explain the observed enhancement of warfarin binding to HSA at low levels of fatty acid.

---

Organizational Affiliation: 

Biophysics Section, Blackett Laboratory, Imperial College of Science, Technology, and Medicine, London SW7 2BW, United Kingdom.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

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

Macromolecule Content

• Total Structure Weight: 68.25 kDa 
• Atom Count: 4,728 
• Modelled Residue Count: 583 
• Deposited Residue Count: 585 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SERUM ALBUMIN	A	585	Homo sapiens	Mutation(s): 0  Gene Names: ALB, GIG20, GIG42, PRO0903, PRO1708, PRO2044, PRO2619, PRO2675, UNQ696/PRO1341
UniProt & NIH Common Fund Data Resources
Find proteins for P02768 (Homo sapiens) Explore P02768  Go to UniProtKB:  P02768
PHAROS:  P02768

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SWF	H [auth A]	S-WARFARIN C19 H16 O4 PJVWKTKQMONHTI-HNNXBMFYSA-N
MYR	B [auth A], C [auth A], D [auth A], E [auth A], F [auth A], G [auth A]	MYRISTIC ACID C14 H28 O2 TUNFSRHWOTWDNC-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
SWF	Binding MOAD:  1HA2	Kd: 2900 (nM) from 1 assay(s)
	PDBBind:  1HA2	Kd: 2900 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.247 
• R-Value Work: 0.201 
• R-Value Observed: 0.201 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 187.541	α = 90
b = 38.774	β = 105.38
c = 95.795	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
MOSFLM	data reduction
SCALA	data scaling
CCP4	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2001-06-20 
Deposition Author(s): Petitpas, I., Bhattacharya, A.A., Curry, S.

Revision History  

• Version 1.0: 2001-06-20
  Type: Initial release
  
• Version 1.1: 2011-11-09
  Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Other, Refinement description, Source and taxonomy, Version format compliance
• Version 1.2: 2019-07-24
  Changes: Data collection