has role independent continuant NADP(+) metabolite nicotinic acid dinucleotide calcium channel agonist signalling molecule nicotinate-adenine dinucleotide phosphate(4-) nicotinic acid-adenine dinucleotide phosphate A nicotinic acid dinucleotide that is NADP(+) in which the carboxamide group on the pyridine ring is replaced by a carboxy group.