title: Structure of the mammalian NOS regulator dimethylarginine dimethylaminohydrolase: A basis for the design of specific inhibitors.
abstract: Dimethylarginine dimethylaminohydrolase (DDAH) is involved in the regulation of nitric oxide synthase (NOS) by metabolizing the free endogenous arginine derivatives N(omega)-methyl-L-arginine (MMA) and N(omega),N(omega)-dimethyl-L-arginine (ADMA), which are competitive inhibitors of NOS. Here, we present high-resolution crystal structures of DDAH isoform 1 (DDAH-1) isolated from bovine brain in complex with different inhibitors, including S-nitroso-L-homocysteine and Zn2+, a regulator of this mammalian enzyme. The structure of DDAH-1 consists of a propeller-like fold similar to other arginine-modifying enzymes and a flexible loop, which adopts different conformations and acts as a lid at the entrance of the active site. The orientation and interaction mode of inhibitors in the active site give insight into the regulation and the molecular mechanism of the enzyme. The presented structures provide a basis for the structure-based development of specific DDAH-1 inhibitors that might be useful in the therapeutic treatment of NOS dysfunction-related diseases.
authors.affiliation: Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Frey
authors.forename: Oliver
authors.initials: O
authors.lastname: Braun
authors.forename: Christophe
authors.initials: C
authors.lastname: Briand
authors.forename: Milan
authors.initials: M
authors.lastname: Vasák
authors.forename: Markus G
authors.initials: MG
authors.lastname: Grütter
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000737:chemistry; D001921:Brain / Q000201:enzymology; D002417:Cattle; D002956:Citrulline / Q000737:chemistry; D003461:Crystallography; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000737:chemistry*; D006710:Homocysteine / Q000031:analogs & derivatives* / Q000737:chemistry; D007527:Isoenzymes; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000378:metabolism; D011487:Protein Conformation; D015032:Zinc / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D006710:Homocysteine; C079202:S-nitrosohomocysteine; D002956:Citrulline; D001120:Arginine; D019001:Nitric Oxide Synthase; D000581:Amidohydrolases; C059999:dimethylargininase; D015032:Zinc