NADPiin

NADPiin is a hypothetical nucleotide analogue envisioned in theoretical discussions of nicotinamide adenine dinucleotide phosphate (NADP) chemistry. The name combines NADP with the suffix 'iin,' indicating an engineered moiety introduced in modern models as an isosteric replacement within the dinucleotide framework. There is no established experimental synthesis or peer-reviewed characterization of NADPiin in the published literature.

In proposed models, NADPiin would resemble NADP in overall architecture, retaining the adenosine and nicotinamide sections but featuring a modified phosphate backbone that includes a synthetic linker. This modification is speculated to alter redox properties, binding affinity to NADP-dependent enzymes, and resistance to hydrolysis, enabling theoretical exploration of how small changes to charge distribution and geometry might affect catalysis.

The concept is used primarily as a thought experiment to study enzyme specificity and cofactor promiscuity. As such, NADPiin has not been associated with concrete biological roles, kinetic data, or pharmacological applications, and it remains outside standard biochemical nomenclature.

Given the lack of experimental evidence, NADPiin is not recognized as a real metabolite and is not part of standard biochemical nomenclature. It appears only in speculative discussions and theoretical models that explore how alterations to dinucleotide structure could influence enzyme recognition. See also NADP, NADPH, nicotinamide adenine dinucleotide.