Presence Of Spermine Research Articles

Differences between the structures of poliovirus and sindbis virus infectious ribonucleic acids

The presence of spermine during heating and quick cooling of the infectious RNA of Sindbis virus increased the survival 11-fold; a four-fold increase was obtained with diaminohexane; no protection was afforded by amines of shortest chain length. None of the amines tested protected poliovirus RNA against heat.

Factors influencing the puromycin-induced release of protein from liver ribosomes

The puromycin-dependent release of labelled polypeptides from rat-liver ribosomes prelabelled in vitro was studied in the presence of spermine at a concentration that effectively blocks amino acid incorporation. 1. 1. Monovalent ions greatly increased the extent of the release, showing an ion specificity essentially similar to that of amino acid incorporation. The increase continued even at a concentration of 1.6 M. The release increased with pH until a plateau was reached around pH 9. 2. 2. The release was stimulated by low concentrations of cell sap. At higher concentrations the recovery of solubilized, labelled polypeptides gradually decreased. It was mainly the initial velocity of the release reaction that was stimulated. The effects of cell sap and KCl were additive. The active component in the cell sap was high-molecular and thermolabile but heterogenous. Rat serum had some activity, but not bovine albumin. Although the release, both in the presence and absence of cell sap, was stimulated by glutathione, it was not inhibited by SH reagents. 3. 3. The sedimentation pattern of the release products was studied by densitygradient centrifugation. Most of the released proteins remained in the top fraction. These proteins were only to a small extent precipitable at pH 5. 4. 4. It is inferred that high concentrations of KCl or NH 4Cl act by making a larger proportion of the ribosomes available to the action of puromycin, probably by increasing their conformational plasticity. The interaction between the bound polypeptides and puromycin seems to be enzymically catalyzed by the cell sap factor(s).

MECHANISM OF PROTECTION OF CELLS BY SPERMINE AGAINST LYSOZYME-INDUCED LYSIS

Grossowicz, Nathan (Hebrew University Hadassah Medical School, Jerusalem, Israel) and Miriam Ariel. Mechanism of protection of cells by spermine against lysozyme-induced lysis. J. Bacteriol. 85:293-300. 1963.-Spermine (1 to 5 x 10(-3)m) was found to prevent lysis of Micrococcus lysodeikticus cells by lysozyme. This protection is due to the rapid and efficient stabilization by spermine of the protoplasts formed by lysozyme, and not to interference with the enzymatic activity. This conclusion concerning the spermine effect is based on chemical and microscopic evidence: (i) the amount of hexosamine, released from lysozyme-treated cells, was equal to or even higher in the presence of spermine than in its absence; (ii) microscopic and electron microscopic pictures showed clearly that the spermine-protected structures resembled protoplasts. On the other hand, the "spermine protoplasts" showed a high stability against hypotonic conditions in comparison with "sucrose protoplasts." The spermine-protoplast complex was very stable and could not be destroyed by water and various agents (NaCl, KCl, MgCl(2), cadaverine, and putrescine). A number of bases such as histamine, d-histidine, and streptomycin exhibited an effect similar to that of spermine, while diamines like cadaverine, putrescine, basic amino acids (lysine, arginine, l-histidine), as well as cations like magnesium, were virtually inactive.

Effect of Spermine on Tissue Oxidations.

Little is known of the biological rôle of spermine (N, N′-dipropylamino-diaminobutane) despite its widespread occurrence in mammalian tissues (human semen, bovine pancreas, spleen, thyroid, lung, ovary, brain, ocular tissue, muscle, liver, and intestine). We have isolated spermine from dilute acid extracts of swine duodenal mucosa. The fact that these extracts produce a hyperglycemia in rabbits led us to investigate the effects of the pure base on the blood sugar level. The intramuscular injection of 15–25 mg per kilo of spermine into fasted, male rabbits weighing about 2 kilos, induces a definite and prolonged hyperglycemia. In order to illuminate further the effects of spermine on the intact organism we have undertaken a general study of the action of the base on the respiration of isolated mammalian tissues. The addition of spermine to guinea-pig brain brei suspended in a phosphate-saline medium has little immediate effect on the respiration as measured by the direct Warburg technic. However, in an extensive series of experiments, a slight increase of oxygen consumption in the presence of spermine was noted, especially during the third and fourth hour following the addition of the amine. If glucose is present as a substrate for either brain brei or brain slices (cortex), the addition of spermine causes a marked inhibition of the oxygen consumption (for typical experiments see Table I. Exps. 11, 13, 81). This inhibition (calculated as % inhibition of the extra oxygen consumption due to glucose) shows a tendency to decrease with time, especially when brain slices are used. The averaged data from a series of 8 experiments on brain brei gave values of 75, 74, 73, and 65% inhibition of oxygen consumption by 0.0060 M spermine in each of the 4 thirty-minute periods following addition of the amine.