The invention relates to 2-O sulfatase and uses thereof. In particular, the invention relates to recombinantly produced 2-O sulfatase, functional variants and nucleic acid molecules that encode these molecules. The invention also provides methods of using 2-O sulfatase for a variety of purposes, including degrading and analyzing glycosaminoglycans (GAGs) present in a sample. For instance, 2-O sulfatase may be used for determining the purity, identity, composition and sequence of glycosaminoglycans present in a sample. The invention also relates to methods of inhibiting angiogenesis and cellular proliferation as well as methods for treating cancer, neurodegenerative disease, atherosclerosis and microbial infection using 2-O sulfatase and/or GAG fragments produced by degradation with 2-O sulfatase.