Sperm Coating Mechanism from the 1.8 A Crystal Structure of Pdc-109-Phosphorylcholine Complex
Wah, D.A., Fernandez-Tornero, C., Sanz, L., Romero, A., Calvete, J.J.(2002) Structure 10: 505
- PubMed: 11937055 
- DOI: https://doi.org/10.1016/s0969-2126(02)00751-7
- Primary Citation of Related Structures:  
1H8P - PubMed Abstract: 
Bovine seminal plasma PDC-109 binds to sperm surface choline lipids and promotes sperm capacitation by stimulating the efflux of cholesterol and phospholipids. The structure of PDC-109 with bound phosphorylcholine was solved using MAD data of a single platinum site. Its two globular (40 x 50 x 20 A(3)) Fn2 domains are linked and clustered by a short polypeptide. The choline binding sites lie at the same face of the molecule. Phosphorylcholine binds to the Fn2 domains through a cation-pi interaction between the quaternary ammonium group and a core tryptophan, plus hydrogen bonding between hydroxyls of exposed tyrosines and the phosphate group. The structure of the PDC-109-oPC complex provides a structural ground for the sperm membrane-coating mechanism underlying PDC-109-induced capacitation.
Organizational Affiliation: 
Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.