Figure 1.
Role of DDAH and DDAH inhibitors. (A) NO synthase isoforms convert arginine (1) to citrulline (2) and NO. Dimethylarginine (3) inhibits all isoforms of NO synthase and is catabolized to (2) and dimethylamine by DDAH. (B) Structures of selected substrate-based DDAH inhibitors: 4, 4124W; 5, L-257; 6, N5-(1-iminopentyl)-l-ornithine; 7, N5-(1-iminobut-3-enyl)-l-ornithine; 8, 2-chloroacetamidine; and 9, N-but-3-ynyl-2-chloroacetamidine.