Fertilins. ADAM 1a Protein . ADAM 2 Protein . ADAM1 Protein . ADAM1a Protein . ADAM2 Protein . Fertilin . Fertilin Protein . Fertilin alpha . Fertilin beta . PH 30 Fusion Protein . PH-30 Fusion Protein . PH-30 Protein . PH-30 alpha . PH-30 beta . PH 30 Protein . PH 30 alpha . PH 30 beta . alpha, Fertilin . alpha, PH-30 . beta, Fertilin . beta, PH-30 . Sperm surface proteins involved in sperm-egg fusion. They consist of two subunits, fertilin alpha (ADAM1a) and beta (ADAM2), both of which belong to the metalloprotease-disintegrin protein family. The beta subunit does not have catalytic activity. . 1.00