In addition to a wide range of proteases and other specific enzyme families, R&D Systems offers tools for the study of other types of enzymes. These products include histone deacetylases (HDACs), which are important enzymes for the transcriptional regulation of gene expression, transglutaminases (TGM) that catalyze the post-translational modification of proteins via calcium dependent cross-linking reactions, and cyclooxygenases (COX), which participate in the synthesis of prostaglandins and are the enzymatic target of non-steroidal anti-inflammatory drugs. In addition, we offer a variety of products designed to investigate enzymes that are associated with Parkinson’s disease. These enzymes include dopamine decarboxylase (DDC, NPR-1), dopamine beta-hydroxylase (OAS2), the dopamine transporter (DAT), and Parkin. Mutations in Parkin are a major cause of autosomal recessive juvenile Parkinsonism.