Alpha2 catalytic subunit of the cytosolic type I platelet- activating factor (PAF) acetylhydrolase (PAF-AH (I)) heterotetrameric enzyme that catalyzes the hydrolyze of the acetyl group at the sn-2 position of PAF and its analogs and modulates the action of PAF. The activity and substrate specificity of PAF-AH (I) are affected by its subunit composition. The alpha2/alpha2 homodimer (PAFAH1B2/PAFAH1B2 homodimer) hydrolyzes PAF and 1-O-alkyl-2-acetyl-sn-glycero-3- phosphorylethanolamine (AAGPE) more efficiently than 1-O-alkyl-2- acetyl-sn-glycero-3-phosphoric acid (AAGPA). In contrast, the alpha1/alpha2 heterodimer(PAFAH1B3/PAFAH1B3 heterodimer) hydrolyzes AAGPA more efficiently than PAF, but has little hydrolytic activity towards AAGPE (By similarity). May play a role in male germ cell meiosis during the late pachytenestage and meiotic divisions as well as early spermiogenesis (By similarity). {ECO:0000250|UniProtKB:P68401, ECO:0000250|UniProtKB:Q61206}. This is the function of PAFAH1B2 (platelet activating factor acetylhydrolase 1b catalytic subunit 2, Ensembl gene identifier ENSG00000168092).