GO:0003905

Catalysis of the reaction: DNA with alkylated base + H2O = DNA with abasic site + alkylated base. This reaction is the hydrolysis of DNA by cleavage of the N-C1' glycosidic bond between the target damaged DNA base and the deoxyribose sugar to remove an alkylated base, leaving an apyrimidinic or apurinic site. [EC:3.2.2.21, GOC:elh, PMID:10872450, PMID:9224623]