Biological Ion Exchanger Resins

Damadian, Raymond

doi:10.1016/s0006-3495(71)86251-3

Cited by 38 publications

(3 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the intracellular magnesium is bound to macromolecules and soluble compounds such as ATP and ADP. The intracellular concentration of free magnesium is reported to be in the range 1-5 mM (Lusk et al, 1968;Damadian, 1971). We also studied the effect of magnesium on the formation of Z-DNA in superhelical pBR322.…”

Section: Z-dna Under Ionic Conditions Close To Physiologicalmentioning

confidence: 97%

Formation of Z-DNA in negatively supercoiled plasmids is sensitive to small changes in salt concentration within the physiological range.

Azorı́n¹,

Nordheim²,

Rich³

1983

The EMBO Journal

View full text Add to dashboard Cite

Negative supercoiling of the plasmid pBR322 with or without an insert of (dG‐dC)n induces the formation of Z‐DNA as measured by the binding of antibodies specific for Z‐DNA. Increasing the concentration of Na+ (or K+) is shown to inhibit the B to Z‐DNA conversion. This may be due to the effect of the cation on the B‐Z junction. Using the data for B to Z‐DNA conversion of the (dG‐dC)n inserts, we have estimated the free energy change per base pair as well as the energy of the B‐Z junction. In pBR322, a 14‐bp segment [CACGGGTGCGCATG] is believed to form Z‐DNA at bacterial negative superhelical densities under salt conditions which are similar to those found in vivo.

show abstract

Section: Z-dna Under Ionic Conditions Close To Physiologicalmentioning

confidence: 97%

Formation of Z-DNA in negatively supercoiled plasmids is sensitive to small changes in salt concentration within the physiological range.

Azorı́n¹,

Nordheim²,

Rich³

1983

The EMBO Journal

View full text Add to dashboard Cite

show abstract

“…The K+ pool in the cells also serves as an electrochemical, chemiosmotic reservoir for energy transduction (2,3). Several investigators have examined the cel lular contents of inorganic cations in Escherichia coli K-12 and showed that K+ is essential for cells to grow exponentially (4)(5)(6)(7). The K+ pool is maintained with a supply of metabolic energy and Rb+ was found to substitute for K+ only partially 304 H. NAKAJIMA, I. YAMATO, and Y. ANRAKU (8).…”

mentioning

confidence: 99%

Quantitative Analysis of Potassium Ion Pool in Escherichia coli K-121

Nakajima

Yamato

Anraku

1979

The Journal of Biochemistry

View full text Add to dashboard Cite

Properties of the K+ pool of Escherichia coli K-12 and its roles in the bacterial growth were studied quantitatively. Cells are able to maintain 240 mm K+ in the pool irrespective of K+ concentrations in the medium and against a concentration gradient of more than 5 orders of magnitude. The amount of K+ in the pool strictly determines the rate of growth and growth yield. Cells cease to grow when the K+ concentration in the pool is down to about 25 mat. Rb+ is not able to substitute for K+ in the K+ pool completely and the rates of growth of cells become slower when more of the K+ in the pool is replaced by Rb+-Most K+ in the pool exists in an osmotically active form but 10 to 20% of the K+ is resistant to changes in osmolarity and temperature of the medium and maintained in the cells depending on the supply of endogenous metabolic energy.

show abstract

“…The association of mobile ions with counter charges on macromolecules provides an explanation for the net accumulation of ions against an "apparent concentration gradient" (1). It remains to be specified, however, what the laws of molecular interaction are that endow both biological and synthetic ion exchangers with the ability to discriminate between ions of like charge.…”

mentioning

confidence: 99%

Biological Ion Exchanger Resins

Damadian¹,

Goldsmith²,

Zaner³

1971

Biophysical Journal

Self Cite

View full text Add to dashboard Cite

Biological selectivity is shown to vary with medium osmotic strength and temperature. Selectivity reversals occur at 4 degrees C and at an external osmolality of 0.800 indicating that intracellular hydration and endosolvent (intracellular water) structure are important determinants in selectivity. Magnetic resonance measurements of line width by steady-state nuclear magnetic resonance (NMR) indicate a difference in the intracellular water signal of 16 Hz between the K form and Na form of Escherichia coli, providing additional evidence that changes in the ionic composition of cells are accompanied by changes in endosolvent structure. The changes were found to be consistent with the thermodynamic and magnetic resonance properties of aqueous electrolyte solutions. Calculation of the dependence of ion-pairing forces on medium dielectric reinforces the role of endosolvent structure in determining ion exchange selectivity.

show abstract

Biological Ion Exchanger Resins

Cited by 38 publications

References 20 publications

Formation of Z-DNA in negatively supercoiled plasmids is sensitive to small changes in salt concentration within the physiological range.

Formation of Z-DNA in negatively supercoiled plasmids is sensitive to small changes in salt concentration within the physiological range.

Quantitative Analysis of Potassium Ion Pool in Escherichia coli K-121

Biological Ion Exchanger Resins

Contact Info

Product

Resources

About