S-adenosylhomocysteine hydrolase belongs to the adenosylhomocysteinase family. It catalyzes the reversible hydrolysis of S-adenosylhomocysteine (AdoHcy) to adenosine (Ado) and L-homocysteine (Hcy). Thus, it regulates the intracellular S-adenosylhomocysteine (SAH) concentration thought to be important for transmethylation reactions. Deficiency in this protein is one of the different causes of hypermethioninemia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. Adenosylhomocysteinase is an enzyme that converts S-adenosylhomocysteine to homocysteine and adenosine. This enzyme catalyses the following chemical reaction: S-adenosyl-L-homocysteine + H2O? L-homocysteine + adenosine. The enzyme contains one tightly bound NAD+ per subunit.    http://www.creative-enzymes.com/product/Adenosylhomocysteinease-From-Human-Recombinant_718.html