Showing papers on "Polyamine binding published in 1991"
TL;DR: Most polyamines exist as a polyamine-RNA complex in cells under the conditions that globin synthesis is stimulated by spermine in a rabbit reticulocyte cell-free system and the amount of sPermine bound to RNA was very close to the value estimated in the cells.
321 citations
TL;DR: The results indicate that the spermidine and putrescine transport system can be defined as a bacterial periplasmic transport system.
113 citations
TL;DR: The uptake, binding and release of the polyamines, spermidine and spermine, and of their diamine precursor, putrescine, were examined in synaptosomal preparations from rat hippocampus and specific polyamine binding evidently occurs selectively on the inner but not on the outer synaptoomes.
57 citations
TL;DR: There may be a functional interaction between polyamines and CKII in living cells, especially in the response to cell growth factors and trophic hormones, according to observations made using isolated recombinant alpha and beta subunits of the kinase.
47 citations
TL;DR: It was found that PhTX analogues with photoaffinity labels may be useful in the isolation/purification of various glutamate and nicotinic acetylcholine receptors; they could also been useful in structural studies of receptors and their binding sites.
Abstract: 125I2-iodinated philanthotoxin-343 (PhTX-343), [125I2]PhTX-343-arginine, and [125I2]PhTX-343-lysine were synthesized and evaluated as probes for glutamate receptors in rat brain synaptic membranes. It was found that these probes were not specific for the glutamate receptors but may be useful for investigating the polyamine binding site. Filtration assays with Whatman GF/B fiber glass filters were unsuitable because the iodinated PhTX-343 analogues exhibited high nonspecific binding to the filters, thus hindering detection of specific binding to membranes. When binding was measured by a centrifugal assay, [125I2]PhTX-343-lysine bound with low affinity (KD = 11.4 +/- 2 microM) to a large number of sites (37.2 +/- 9.1 nmol/mg of protein). The binding of [125I2]PhTX-343-lysine was sensitive only to the polyamines spermine and spermidine, which displaced [125I2]PhTX-343-lysine with Ki values of (3.77 +/- 1.4) x 10(-5) M and (7.51 +/- 0.77) x 10(-5) M, respectively. The binding was insensitive to glutamate receptor agonists and antagonists. Binding results with [125I2]PhTX-343-arginine were similar to those of [125I2]-PhTX-343-lysine. Considering the high number of toxin binding sites (10000-fold more than glutamate) in these membranes and the insensitivity of the binding to almost all drugs that bind to glutamate receptors, it is evident that most of the binding observed is not to glutamate receptors. On the other hand, PhTX analogues with photoaffinity labels may be useful in the isolation/purification of various glutamate and nicotinic acetylcholine receptors; they could also be useful in structural studies of receptors and their binding sites.
26 citations
TL;DR: Interactions between the putative polyamine binding site and previously described sites for glutamate and glycine were investigated to investigate interactions between spermidine and PCP receptor ligand sites.
13 citations