Question: What is the biological function of the polyamines?

All living organisms employ a complex array of regulatory mechanisms to hold constant the intracellular polyamine (PA) pool size. Putrescine, cadaverine, spermidine and spermine are biologically ubiquitous alkylamines bearing, at physiological pH values, positive charge on their primary and secondary amino groups. PAs are considered to be universal cellular regulators and can be found in free or conjugated forms (1). As polycations they interact with negatively-charged DNA, RNA, proteins, phospholipids, and nucleoside triphosphates. Far from behaving merely as cations, PAs can also participate in hydrophobic interactions through their methylene bridging groups. Variations among different PAs, in the number and in the distance of amino groups, provide for their functional specificity