Biomaterial Database

Metabolism of nicotinamide mononucleotide in beef liver. 1987

T Imai, and B M Anderson

Nicotinamide mononucleotide (NMN) is not only an intermediate for the biosynthesis but also a degradation product of pyridine cofactors in animal tissues. Among the animal tissues tested, the highest NMN catabolizing activity was detected in beef liver (5.6 mumol/min/g tissue). This activity was 16 times higher than the NAD hydrolysis catalyzed by the liver NAD glycohydrolase. As a result of enzymatic analysis of the NMN splitting process, two types of enzyme responsible for this catabolism were partially purified and identified as a membrane-bound 5'-nucleotidase and a cytoplasmic nicotinamide riboside (NR) phosphorylase. No specific NMN glycohydrolase could be found in contrast to results observed in bacterial systems. The 5'-nucleotidase and NR phosphorylase constitute an obligatory process of the pyridine nucleotide cycle. The dephosphorylation and phosphorolysis catalyzed suggest that these enzymes could serve as an important mechanism for salvaging the ribose and nicotinamide moieties of NMN and pyridine nucleotides in the cell and a process that could be regulated at the mononucleotide level by this "NMN cycle" rather than by a NAD glycohydrolase cycle. In addition to the enzymatic properties of these enzymes, a regulatory mechanism by nucleotides such as ATP was also demonstrated.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D009244	NAD+ Nucleosidase	An enzyme that catalyzes the hydrolysis of nicotinamide adenine dinucleotide (NAD) to NICOTINAMIDE and ADENOSINE DIPHOSPHATE RIBOSE. Some are extracellular (ectoenzymes).The enzyme from some sources also catalyses the hydrolysis of nicotinamide adenine dinucleotide phosphate (NADP).	DPNase,Diphosphopyridine Nucleotidase,NAD+ Glycohydrolase,NADase,Diphosphopyridine Nucleotidases,Ecto-NAD+ Glycohydrolase,NAD(P) Nucleosidase,NAD+ Nucleosidases,NAD-Glycohydrolase,NAD-Glycohydrolases,NADP Nucleosidase,NADP-Glycohydrolase,NADases,Ecto NAD+ Glycohydrolase,Glycohydrolase, Ecto-NAD+,Glycohydrolase, NAD+,NAD Glycohydrolase,NAD Glycohydrolases,NADP Glycohydrolase,Nucleosidase, NAD+,Nucleosidase, NADP,Nucleosidases, NAD+,Nucleotidase, Diphosphopyridine,Nucleotidases, Diphosphopyridine
D009537	Nicotinamide Mononucleotide	3-Carbamoyl-1-beta-D-ribofuranosyl pyridinium hydroxide-5'phosphate, inner salt. A nucleotide in which the nitrogenous base, nicotinamide, is in beta-N-glycosidic linkage with the C-1 position of D-ribose. Synonyms: Nicotinamide Ribonucleotide; NMN.	Mononucleotide, Nicotinamide
D009699	N-Glycosyl Hydrolases	A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.	Glycoside Hydrolases, Nitrogen-linked,Hydrolases, N-Glycosyl,Nucleosidase,Nucleosidases,Nucleoside Hydrolase,Nitrogen-linked Glycoside Hydrolases,Nucleoside Hydrolases,Glycoside Hydrolases, Nitrogen linked,Hydrolase, Nucleoside,Hydrolases, N Glycosyl,Hydrolases, Nitrogen-linked Glycoside,Hydrolases, Nucleoside,N Glycosyl Hydrolases,Nitrogen linked Glycoside Hydrolases
D009708	Nucleotidases	A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.
D011683	Purine-Nucleoside Phosphorylase	An enzyme that catalyzes the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. EC 2.4.2.1.	Inosine Phosphorylase,Nicotinamide Riboside Phosphorylase,Purine Nucleoside Phosphorylases,Nucleoside Phosphorylases, Purine,Phosphorylase, Inosine,Phosphorylase, Nicotinamide Riboside,Phosphorylase, Purine-Nucleoside,Phosphorylases, Purine Nucleoside,Purine Nucleoside Phosphorylase,Riboside Phosphorylase, Nicotinamide
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia