Dimethylarginine Dimethylaminohydrolase 2 (DDAH2)

Dimethylarginine dimethylaminohydrolase (DDAH) regulates cellular methylarginine concentrations, which in turn inhibit nitric oxide synthase activity. The DDAHII amino acid sequence shares 98% identity with that of its mouse homolog and 62% identity with the sequence of DDAHI. Northern blot analysis detected a 2.0-kb DDAHII transcript expressed at highest levels in heart, kidney, and placenta.Recombinant DDAHII metabolized ADMA and L-NMMA, but not SDMA or L-arginine, demonstrating that DDAHII is a functional homolog of DDAHI.DDAH2 reduced the secretion of ADMA, increased VEGF mRNA expression, and enhanced tube formation by cells grown in a 3-dimensional medium. A DDAH inhibitor reduced tube formation in human umbilical vein endothelial cells.