Nmnat1, also known as nicotinamide/nicotinic acid mononucleotide adenylyltransferase1, is a central enzyme in NAD biosynthesis, catalyzing the condensation of nicotinamide mononucleotide (NMN) of nicotinic acid mononucleotide (NaMN) with the AMP moiety of ATP to form NAD or NaAD. It is widely expressed with high levels in skeletal muscle, heart, liver and kidney. This protein appears to have the ability to protect against axonal degeneration following mechanical or toxic insults. Recombinant mouse Nmnat1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.