The structure of platelet-activating factor acetylhydrolase (PAF-AH) isolated from boar seminal plasma and examined using mass spectrometry*

Platelet-activating factor – acetylhydrolase (PAF-AH) – of boar seminal plasma is a heterogeneous protein consisting of four polypeptides with molecular weights of 43, 55, 65 and 100 kDa. In 2004 the authors of the current report demonstrated that the N-terminal amino acid sequence of 43 kDa polypeptide is homologous with the amino acid sequences of the IgG-binding proteins and zona pellucida-binding adhesion proteins. In the current report, due to the strongly blocked Nterminal amino groups of 55, 65 and 100 kDa polypeptides, their molecular structure was examined with mass spectrometry. In the PAF-AH complex structure the presence of epididymis-specific α-mannosidase, fibronectin, spermadhesins AWN-1 and PSP-II, and IgG-binding proteins was