Spermidine inhibits NOS1 (nNOS). Spermidine binds and precipitates DNA and may be used for purification of DNA binding proteins. Spermidine activates PNK (polynucleotide kinase T4). Spermidine binds to and activates NMDA and has been shown to potentiate NMDA-induced currents in a concentration-dependent manner.

Flavin adenine dinucleotide (FAD) is a REDOX cofactor and protein cogroup involved in various metabolic reactions.

N-Acetyl-L-alanine is a substrate for Guanine nucleotide-binding protein G(I)/G(S)/G(O) gamma-2 subunit Myelin basic protein GTP-binding nuclear protein Ran Tropomyosin alpha 4 chain HIV-1 Rev binding protein 2 Xaa-Pro dipeptidase Thymosin beta-10 Actin-like protein 3 Alanine aminotransferase Serine/threonine protein phosphatase PP1-beta catalytic subunit 10 kDa heat shock protein (mitochondrial) Calmodulin and Beta-1-syntrophin.