TY  - JOUR
AU  - Boix, E.
AU  - Pulido, D.
AU  - Moussaoui, M.
AU  - Nogues, M. V.
AU  - Russi, S.
AU  - DESY
TI  - The sulfate-binding site structure of the human eosinophil cationic protein as revealed by a new crystal form
JO  - Journal of structural biology
VL  - 179
SN  - 1047-8477
CY  - San Diego, Calif.
PB  - Elsevier
M1  - PHPPUBDB-25783
SP  - 1-9
PY  - 2012
AB  - The human eosinophil cationic protein (ECP), also known as RNase 3, is an eosinophil secretion protein that is involved in innate immunity and displays antipathogen and proinflammatory activities. ECP has a high binding affinity for heterosaccharides, such as bacterial lipopolysaccharides and heparan sulfate found in the glycocalix of eukaryotic cells. We have crystallized ECP in complex with sulfate anions in a new monoclinic crystal form. In this form, the active site groove is exposed, providing an alternative model for ligand binding studies. By exploring the protein-sulfate complex, we have defined the sulfate binding site architecture. Three main sites (S1-S3) are located in the protein active site; S1 and S2 overlap with the phosphate binding sites involved in RNase nucleotide recognition. A new site (S3) that is unique to ECP is one of the key anchoring points for sulfated ligands. Arg 1 and Arg 7 in S3, together with Arg 34 and Arg 36 in S1, form the main basic clusters that assist in the recognition of ligand anionic groups. The location of additional sulfate bound molecules, some of which contribute to the crystal packing, may mimic the binding to extended anionic polymers. In conclusion, the structural data define a binding pattern for the recognition of sulfated molecules that can modulate the role of ECP in innate immunity. The results reveal the structural basis for the high affinity of ECP for glycosaminoglycans and can assist in structure-based drug design of inhibitors of the protein cytotoxicity to host tissues during inflammation.
KW  - Amino Acid Sequence
KW  - Catalytic Domain
KW  - Crystallization
KW  - Eosinophil Cationic Protein: chemistry
KW  - Eosinophil Cationic Protein: metabolism
KW  - Glycosaminoglycans: chemistry
KW  - Glycosaminoglycans: metabolism
KW  - Humans
KW  - Ligands
KW  - Molecular Dynamics Simulation
KW  - Molecular Sequence Data
KW  - Protein Binding
KW  - Protein Conformation
KW  - Recombinant Proteins: chemistry
KW  - Recombinant Proteins: metabolism
KW  - Sulfates: chemistry
KW  - Glycosaminoglycans (NLM Chemicals)
KW  - Ligands (NLM Chemicals)
KW  - Recombinant Proteins (NLM Chemicals)
KW  - Sulfates (NLM Chemicals)
KW  - Eosinophil Cationic Protein (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:22579681
UR  - <Go to ISI:>//WOS:000305775400001
DO  - DOI:10.1016/j.jsb.2012.04.023
UR  - https://bib-pubdb1.desy.de/record/144054
ER  -