Enzymes that catalyze the reversible reduction of NAD by NADPH to yield NADP and NADH. This reaction permits the utilization of the reducing properties of NADPH by the respiratory chain and in the reverse direction it allows the reduction of NADP for biosynthetic purposes.

Integral membrane proteins that transport protons across a membrane. This transport can be linked to the hydrolysis of ADENOSINE TRIPHOSPHATE. What is referred to as proton pump inhibitors frequently is about POTASSIUM HYDROGEN ATPASE.

Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)

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)