The acetylation of polyamines in Escherichia coli.

The polyamines putrescine (NH2(CH2)4NHs), spermidine (NH~(CH&NH(CH,)~~HZ), and spermine (NH2(CH&NH(CH2)fiH(CH&NH2) are widely distributed in nature. Fungi and animal tissues contain mainly spermidine and spermine (l6), whereas bacteria, especially gram-negative bacteria, contain mainly putrescine and spermidine (5-7) ; the amines have also been found in many plantsi (8) and in bacterial viruses (9, 10). They have been shown to be active in a number of biological systems. They are growth factors for a fungus (11) and several bacteria (8, 12-14). Spermidine and spermine can antagonize bacteriostasis due to atabrine or quinine (15), and to propamidine (16). They or their degradation products are also toxic towards certain microorganisms (17-21) and can cause acute renal tubular necrosis in animals (21, 22). There is evidence that their action may in part be related to nucleic acid metabolism: they have a high aflinity for nucleic acid in vitro1 (23, 24); they are reported to be bound to nucleic acid in Hemophilus parain$uenza (25), and spermine inhibits nuclease activity in this organism or in vitro (25, 26) ; they are transferred with the deoxyribonucleic acid during infection of Escherichia coli by bacteriophage Tt (9, 27); and they can protect shocked Tz from inactivation (28). Recent work from this laboratory by Tabor et al. (5, 29) on the biosynthesis of the polyamines has demonstrated the incorporation of putrescine into spermidine and spermine in several microorganisms, and in rat prostate; also, the formation of spermidine from putrescine and methionine has been described in detail with use of purified enzyme systems from E. coli (5). A number of studies have been reported bearing on the catabolism of these compounds. Putrescine can be oxidized by E. coli (30), a number of other bacteria (15, 31, 32), and by purified diamine oxidase (33). Spermidine and spermine are also degraded by a variety of bacteria (6, 15, 31, 32, 34), by animal tissues in vivo (4) and in vitro (35), and by the purified plasma amine oxidase (36). However, it has not been possible to demonstrate degradation of spermidine or spermine by many other bacteria, including E. coli, either in studies of oxygen uptake (15, 31) or in experiments with C14-labeled polyamines.’ This report will present the results of investigations into nondegradative transformations of the amines in E. coli. N-Acetylation has been found to occur, and to be a major pathway under certain conditions; five new naturally occurring N-acetyl derivatives have been isolated: monoacetylputrescine (CH3CONH(CH2)4NH2) ;2 two isomeric forms of monoacetylspermidine, monoacetyl-