Effects of Polyamines on Membrane Permeability*

Silver, Simón; Wendt, Louis; Bhattacharyya, Pinakilal; Beauchamp, Rachelle S.

doi:10.1111/j.1749-6632.1970.tb39392.x

Cited by 20 publications

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“…Recent results with the steroidal diamine, irehdiamine A, show that there is not a necessary relationship between single-hit killing and a lack of cooperative interactions at the physiological level. This steroid (which resembles colicin K in its physiological action on E. coli) kills with single-hit kinetics, but shows a sigmoidal (cooperative) relation between steroid concentration and the initial rate of potassium loss (22,23,25). The extent of cooperation is reduced at temperatures below 37 C (25).The apparent inconsistency in the relationship between the extent of killing by colicins and their physiological effects, and the results obtained with the steroid, have prompted a closer examination of three aspects of colicin K action: (i) the relationship between the fraction of cells killed and the fraction which retain potassium, (ii) the relationship between multiplicity and the initial rate of potassium loss, and (iii) the effect 1236…”

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Mechanism of Colicin Action: Early Events

Wendt

1970

J Bacteriol

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The kinetics and the temperature dependence of potassium loss from Escherichia coli cells treated with colicin K have been examined. At 37 C, after a single lethal hit, essentially all of the intracellular potassium is lost within the first few minutes of treatment. The initial rate of loss is linearly related to colicin concentration up to a multiplicity of 30. As the temperature is decreased over the range from 37 to 1 C, an increasing delay is seen in the initiation of potassium loss after colicin adsorption. This delay can be overcome by increasing colicin multiplicity and probably reflects an alteration of the cell membrane at these temperatures. A comparison of this effect with an apparently related effect of temperature on the action of irehdiamine A indicates that the delay may represent the inhibition of a transmission process occurring in the membrane.Colicin K is one of three colicins known to inhibit many energy-dependent processes in Escherichia coil (2,4,12,16) and has been previously shown to inhibit active transport of potassium and to cause the loss of intracellular potassium (17). These effects apparently occur by a direct action on the cell membrane (2) and have been assumed to result from changes which are transmitted over or through the membrane from a local site of action (9,15,16). A physical model which could acc'ount for the possible spreading of the local action of a single colicin molecule has been proposed (3,4). This model supposes that conformational changes may be propagated between membrane subunits in much the same manner as linked subunits of allosteric enzymes respond to the binding of a ligand molecule to one of the units (cooperativity within the membrane).The major evidence for a transmission of the local action of a single colicin molecule seems to be the single-hit killing shown by colicins. The conclusion has been drawn from single-hit killing that a cell attacked by a single colicin molecule has a definite probability of being killed (9,15,16), and this in turn implies that the effect of the single molecule can be transmitted to the whole cell. On this basis it might be expected that the effect of a single lethal unit on a cell should be demonstrable at the level of the affected process as well as at the level of cell killing. That is, at low multiplicities the fraction of the cell population which received single lethal hits should be correlated with the fraction of which the metabolism was blocked. In experimental systems for which data on this point are available, the relationship is not clear. The effects of colicins E2 and E3 are very slow to appear and require high multiplicities before deoxyribonucleic acid or protein synthesis are markedly affected (7,15,17). At low multiplicities (which are still sufficient to kill 95% of the cells), the effects are only slight. The effects of colicins K or El are quite rapid, but the fraction of cells killed is generally greater than the extent of inhibition (5, 6).Another conclusion from the single-hit killing has been that of ...

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Mechanism of Colicin Action: Early Events

Wendt

1970

J Bacteriol

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“…In Esch. coli it is suggested that newly synthesized cell walls are stabilized by the polyamines putrescine and spermidine which are later exchanged for Mg2+ (Silver et al 1970). It is perhaps significant that in the same organism newly synthesized LPS has been shown to be resistant to extraction from the outer membrane (Levy & Leive 1968;Bayer & Leive 1977).…”

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The Influence of Calcium or Manganese on the Resistance to EDTA, Polymyxin B or Cold Shock, and the Composition of Pseudomonas aeruginosa Grown in Glucose‐ or Magnesium‐depleted Batch Cultures

Kenward

Brown

Fryer

1979

Journal of Applied Bacteriology

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Cultures were batch grown in simple salts media in which growth was limited either by depletion of glucose and magnesium (C/Mg‐dep) or by glucose alone (C‐dep). Cultures were also grown in these media supplemented by calcium and/or manganese. All cultures grown in the C‐dep media were sensitive to ethylenediaminetetraacetic acid (EDTA), polymyxin and also to cold shock but were relatively resistant to ethyleneglycol‐bis(2‐aminoethyl ether)‐N, N‐tetraacetic acid (EGTA). Inclusion of calcium or manganese in the growth medium enhanced lysis by EDTA. Cultures grown in the basic C/Mg‐dep media were resistant to EDTA, EGTA, polymyxin and to cold shock. Sensitivity to these agents was retained by cultures grown in C/Mg‐dep media supplemented with Ca2+ and/or Mn2+. Cells grown in C/Mg‐dep media with added Mn2+ were more sensitive to EDTA and polymyxin than those from the unsupplemented C/Mg‐dep media but still resistant compared with C‐dep cultures. All cultures from supplemented C/Mg‐dep media were more sensitive to EGTA than those from any of the C‐dep media. Whole cells and cell walls from these various media had differing amounts of cell wall, phosphorus, amino sugar, carbohydrates, readily extractable lipid (REL), total phospholipid (PL), and especially differences in cell wall divalent metal cation content. The differences in PL, REL and amino sugars and carbohydrate did not correlate with the response of C‐dep and C/Mg‐dep bacteria to EDTA, EGTA or polymyxin. The results are discussed in relation to the hypothesis that the sensitivity of Pseudomonas aeruginosa to polymyxin and EDTA is more dependent on outer membrane cation content rather than on other components, e.g. PL and lipopolysaccharide.

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“…Several functions have been attributed to these polycations: they have been found to stabilize ribosomal structure (Cohen & Lichtenstein, 1960;Norton et al, 1968), stimulate aminoacyl-tRNA synthetases (Doctor et al, 1970), and activate RNA synthesis by DNA-dependent RNA polymerase (Abraham, 1968). The nature of interactions between polyamines and polynucleotides or cell membranes has also been elucidated (Liquori et al, 1967;Gabbay et al, 1970;Silver et al, 1970). Moreover, a 'general' regulatory role of polyamines in the rate of transcription has been proposed (Raina & Jiinne, 1970).…”

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S-Adenosylmethionine decarboxylase from human prostate. Activation by putrescine

Zappia

Cartenı́-Farina

Pietra

1972

Biochemical Journal

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1. The presence of S-adenosylmethionine decarboxylase in human prostate gland is reported. A satisfactory radiochemical enzymic assay was developed and the enzyme was partially characterized. 2. Putrescine stimulates the reaction rate by up to 6-fold at pH7.5: the apparent activation constant was estimated to be 0.13mm. The stimulation is pH-dependent and a maximal effect is observed at acid pH values. 3. Putrescine activation is rather specific: other polyamines, such as spermidine and spermine, did not show any appreciable effect. 4. The apparent K(m) for the substrate is 4x10(-5)m. The calculated S-adenosylmethionine content of human prostate (0.18mumol/g wet wt. of tissue) demonstrates that the cellular amounts of sulphonium compound are saturating with respect to the enzyme. 5. The enzyme is moderately stable at 0 degrees C and is rapidly inactivated at 40 degrees C. The optimum pH is about 7.5, with one-half of the maximal activity occurring at pH6.6. 6. Several carboxy-(14)C-labelled analogues and derivatives of S-adenosylmethionine were tested as substrates. The enzyme appears to be highly specific: the replacement of the 6'-amino group of the sulphonium compound alone results in a complete loss of activity. 7. Inhibition of the enzyme activity by several carbonyl reagents suggests an involvement of either pyridoxal phosphate or pyruvate in the catalytic process. 8. The inhibitory effect of thiol reagents indicates the presence of ;essential' thiol groups.

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Effects of Polyamines on Membrane Permeability*

Cited by 20 publications

References 40 publications

Mechanism of Colicin Action: Early Events

Mechanism of Colicin Action: Early Events

The Influence of Calcium or Manganese on the Resistance to EDTA, Polymyxin B or Cold Shock, and the Composition of Pseudomonas aeruginosa Grown in Glucose‐ or Magnesium‐depleted Batch Cultures

S-Adenosylmethionine decarboxylase from human prostate. Activation by putrescine

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