The productive conformation of prostaglandin G2 at the peroxidase site of prostaglandin endoperoxide H synthase: docking, molecular dynamics, and site-directed mutagenesis studies.
We present a plausible productive conformation obtained by docking calculations for the binding of prostaglandin G2 (PGG2) to the peroxidase site of prostaglandin endoperoxide H synthase-1 (PGHS-1, COX-1). The enzyme-substrate complex stability was verified by molecular dynamics. Structural analysis reveals the requirements for enzyme-substrate recognition and binding: the PGG2 15-hydroperoxide group is in the proximity of the heme iron and participates in a hydrogen bond network with the conserved His207 and Gln203 and a water molecule, whereas the carboxylate group forms salt bridges with the remote Lys215 and Lys222. Site-directed mutagenesis showed that a single mutation of Lys215 or Lys222 does not affect enzyme activity, whereas dual mutation of these residues, to either alanine or glutamate, significantly decreases turnover. This indicates that the conserved cationic pocket is involved in enzyme-substrate binding.
Chubb
Anthony J
AJ
Department of Clinical Pharmacology, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
Fitzgerald
Desmond J
DJ
Nolan
Kevin B
KB
Moman
Edelmiro
E
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D006801:Humans; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011462:Prostaglandins G / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D011462:Prostaglandins G; C038291:prostaglandin G2; D011451:Prostaglandin-Endoperoxide Synthases