Complex sentence: This enzyme then metabolically processes the PAHs to quinone metabolites that bind to DNA in reactive depurinating adducts, resulting in mutations that may contribute to unregulated growth of vascular smooth muscle cells or to their migration to the inside of the artery, steps in plaque formation.
Split into simpler sentences: This enzyme then metabolically processes the PAHs to quinone metabolites that bind to DNA in reactive adducts that remove purine bases. The resulting mutations may contribute to unregulated growth of vascular smooth muscle cells or to their migration to the inside of the artery, which are steps in plaque formation.