Action of Steroidal Diamines on Active Transport and Permeability Properties of Escherichia coli

Abstract

The steroidal diamine irehdiamine A (IDA) is a potent inhibitor of bacteriophage growth and macromolecular synthesis in Escherichia coli. By using radioactive 42K and "4C-thiomethylgalactoside (TMG), rapid effects of IDA and related steroids, both on the influx of potassium and TMG via their respective transport systems and on the efflux (leakage) of radioactivity from the treated cells, have been measured. IDA affects both the influx and efflux of 42K at concentrations of steroid as low as 2 x 10-I M. Because of the increased leakage, it is not possible to tell whether there is a direct effect reducing the rate of active transport of potassium. The primary diamine, IDA, and its bis-secondary, bis-tertiary, and bis-quaternary diamine analogues are decreasingly effective in altering cell permeability properties in the order 10 > 20 > 30 > 4°. The effects of IDA on potassium transport are mirrored by similar effects on the transport of TMG. Therefore, the action of IDA is on the cell membrane and not directly on one or another transport system. The effects of IDA on cell permeability can reasonably explain the inhibitory actions of the drugs on bacteriophage growth and cellular metabolism.

Microbial toxicity of ethanolamines—Multiwalled carbon nanotubes

“…The increase in the amino group substitution on the nanotubes increases the positively cationic nature of this structure which lead to increase the chance of an interaction between the nanotubes and the negative charge on the cell walls of the microorganisms . On the other hand, the interaction of the amine groups of functionalized nanotubes with the cell wall decrease its selective permeability which leads to leakage of the intracellular substance, such as protein, amino acids and glucose dehydrogenase and so, functionalized nanotubes inhibit the normal metabolism of microorganisms and finally lead to death of this cell …”

“…47 On the other hand, the interaction of the amine groups of functionalized nanotubes with the cell wall decrease its selective permeability which leads to leakage of the intracellular substance, such as protein, amino acids and glucose dehydrogenase and so, functionalized nanotubes inhibit the normal metabolism of microorganisms and finally lead to death of this cell. [48][49][50] To study the influence of functional groups on antimicrobial activity, first three functionalized MWCNT with various degree of functionalization were prepared. To illustrate various degree of functionalization, Figure 3(B) were used by aid of TGA.…”

Mechanism of Colicin Action: Early Events

“…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…”

“…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).…”

Mechanism of Action of the Gonadal Steroids Producing Diminution of Growth of Staphylococcus Aureus

“…If the steroids act as postulated a t the cell wall-cell membrane interface, increased leakage would be expected. Various other reports relate leakage phenomena with the binding of agents to cell membranes (Smith, Shay & Doorenbos, 1964;Smith & Shay, 1965;Lampen, 1966;Woodrot€e & Wilkinson, 1966;Varricchio, Doorenbos & Stevens, 1967;Silver & Levine, 1968).…”