The three major polyamines are normally found in chloroplasts of higher plants and are implicated in plant growth and stress response. We have recently shown that putrescine can increase light energy utilization through stimulation of photophosphorylation [Ioannidis et al., (2006) BBA-Bioenergetics, 1757, 821-828]. We are now to compare the role of the three major polyamines in terms of chlorop...

The major polyamine of turnip yellow mosaic virus has been identified as spermidine by gas chromatography and mass spectrometry of the trifluoroacetamido derivative. Very small amounts of putrescine and cadaverine, but not norspermidine, have been detected in the virus. The spermidine contents of numerous virus preparations were in the range 200-700 molecules per virion and were considerably in...

Polyamines play an important role in biology, yet their exact function in many processes is poorly understood. Artificial host molecules capable of sequestering polyamines could be useful tools for studying their cellular function. However, designing synthetic receptors with affinities sufficient to compete with biological polyamine receptors remains a huge challenge. Binding affinities of synt...

5S rRNA is an integral component of the large ribosomal subunit in virtually all living organisms. Polyamine binding to 5S rRNA was investigated by cross-linking of N1-azidobenzamidino (ABA)-spermine to naked 5S rRNA or 50S ribosomal subunits and whole ribosomes from Escherichia coli cells. ABA-spermine cross-linking sites were kinetically measured and their positions in 5S rRNA were localized ...

Tabor, Celia W. (National Institute of Arthritis and Metabolic Diseases, Bethesda, Md.). Stabilization of protoplasts and spheroplasts by spermine and other polyamines. J. Bacteriol. 83:1101-1111. 1962.-Spermine (10(-3)m) or spermidine prevents lysis of lysozyme-produced protoplasts of Escherichia coli W, E. coli B, and Micrococcus lysodeikticus in hypotonic media. Spheroplasts prepared by the ...

Nuclear kinase II (nuclear casein kinase 2) is a multifunctional, second messenger-independent protein serine/threonine kinase that phosphorylates many different nuclear proteins, including high mobility group (HMG) proteins, heterogeneous nuclear ribonuleoprotein (hnRNP) fractions, and nuclear matrix proteins, but not histones. The enzyme appears to be essential in growth regulation. However, ...

Strongly inwardly rectifying potassium channels exhibit potent and steeply voltage-dependent block by intracellular polyamines. To locate the polyamine binding site, we have examined the effects of polyamine blockade on the rate of MTSEA modification of cysteine residues strategically substituted in the pore of a strongly rectifying Kir channel (Kir6.2[N160D]). Spermine only protected cysteines...

We have analyzed the function of spermine in the aminoacylation of tRNA-Val by the valyl-tRNA synthetase of Escherichia coli. Our results indicate that Mg2+ is required for the aminoacylation reaction as well as for the ATP-PP-i exchange catalyzed by this enzyme. The apparent stimulation by spermine is a function of the tRNA used, which appears to contain bound cations even after dialysis again...

While weaning is frequently adopted in animal agriculture to improve economic profit all over the world, the practice presents several problems at the same time. Numerous biological stress responses are evoked by maternal and littermate separations, abrupt changes in society, and environmental changes associated with weaning (Moeser et al., 2007). Weaning stress can contribute to intestinal and...