Polyphosphates as Polyelectrolytes. I. Light Scattering and Viscosity of Sodium Polyphosphates in Electrolyte Solutions<sup>1</sup>

Strauss, Ulrich P.; Smith, Edward H.; Wineman, Philip L.

doi:10.1021/ja01112a017

Cited by 103 publications

(28 citation statements)

References 18 publications

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“…This is also supported by the fact that polyphosphate does not have a rigid secondary structure but is a highly flexible, freely rotating chain as reflected by its short Ͻ8-Å persistence length (18,19).…”

Section: Discussionmentioning

confidence: 58%

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Bolesch

Keasling

2000

Journal of Biological Chemistry

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Exopolyphosphatase of Escherichia coli (PPX) is a highly processive enzyme demonstrating the ability to recognize polyphosphates of specific lengths. The mechanisms responsible for the processivity and polymer length recognition of the enzyme were investigated in relation to the manner in which polyphosphate is bound to the enzyme. Multiple polyphosphate binding sites were identified on distant portions of the enzyme and were determined to be responsible for the polymer length recognition of the enzyme. In addition, two independently folded domains were identified. The N-terminal domain contained a quasi-processive polyphosphatase active site belonging to the sugar kinase/actin/ hsp70 superfamily. The C-terminal domain contained a single polyphosphate binding site and was responsible for nearly all of the PPX affinity for polyphosphate. This domain was also found to confer a highly processive mode of action to PPX. Collectively, these results were used to describe the interaction of polyphosphate with PPX.Polyphosphate up to several thousand phosphate residues in length is known to accumulate in bacteria, fungi, plants, and animals (1). The function of this phosphate biopolymer, although not well understood, is believed to involve energy and phosphate storage, transformation of DNA across cell membranes (2), gene regulation (3), stationary phase survival (4, 5), and response to starvation for amino acids or carbon (6, 7).Exopolyphosphatases are found in a variety of organisms and hydrolyze terminal phosphate bonds to yield orthophosphate (P 1 ). 1 Their metabolic role, however, is unclear, as they appear to waste the stored energy of the phosphate bonds.Escherichia coli exopolyphosphatase, like most exopolyphosphatases, is highly processive, as it hydrolyzes entire polyphosphate chains greater than 1000 phosphate residues in length to orthophosphate without release of polyphosphate intermediates.In contrast, several polyphosphate-degrading enzymes produce specific chain length intermediates by processively removing terminal phosphates from long chain polyphosphates until the specific length intermediate remains and is released. These intermediates range from P 40 for guanosine pentaphosphate phosphohydrolase (GppA) (8) to P 100 , roughly 200-Å in length, for polyphosphate glucokinase of Propionibacterium shermani (9, 10).We have investigated this release of specific polyphosphate intermediates by PPX under conditions non-optimal for activity. Furthermore, we have identified domains of the enzyme and their functions in polyphosphate binding and processivity in order to describe the interaction of polyphosphate with PPX. EXPERIMENTAL PROCEDURESPPX Assays-Radioactive [ 32 P]polyphosphate was synthesized according to reported procedures (11,12). This polyphosphate was used to assay PPX activity with minor modifications to reported methods (8, 13). The 15-l reactions contained 50 mM Tricine-KOH (pH 8.0), 1 mM MgCl 2 , 175 mM KCl, and 100 nM [ 32 P]polyphosphate chains, assuming a chain length of 750 phosphate residue...

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Section: Discussionmentioning

confidence: 58%

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Bolesch

Keasling

2000

Journal of Biological Chemistry

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“…The weight-average molecular weights (Mw) of these "~ 20 samples as well as their fractions were determined by z~ " measuring viscosities of the aqueous solutions in presence of 0.035 N NaBr and employing the following relationship ~" suggested by Strauss et al (2). [2] a Before taking any measurements, solutions of Grahams salt were invariably stored for 24 h after dissolution.…”

Section: Samples Of Grahamsmentioning

confidence: 99%

Molecular - weight distribution in Graham's salt: Dependence on conditions of formation

Bhargava

Srivastava

Varma

1974

Colloid Polymer Sci

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“…Light-scattering by polyphosphates has been investigated by Strauss et al (1,2) and Saini and Trossarelli (3). Strauss et al (1) determined the weight-average molecular weight of samples of Graham Salt*) in solutions using NaBr solution (0.1 M to 0.35 M) as solvent.…”

Section: Introductionmentioning

confidence: 99%

“…Strauss et al (1) determined the weight-average molecular weight of samples of Graham Salt*) in solutions using NaBr solution (0.1 M to 0.35 M) as solvent. Intrinsic viscosities, however, were determined by using 0.035 M NaBr solution as a solvent and the following relationship was established:…”

Section: Introductionmentioning

confidence: 99%

Light-scattering studies on solutions of potassium-polyphosphate

Bhargava

Varma

Agrawal

1978

Colloid Polymer Sci

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Polyphosphates as Polyelectrolytes. I. Light Scattering and Viscosity of Sodium Polyphosphates in Electrolyte Solutions¹

Abstract: Several samples of sodium polyphosphate, covering a molecular weight range from 7000 t o 19000, were prepared by the condensation polymerization of primary sodium phosphate. The viscosity and PH of freshly prepared solutions decreased

Cited by 103 publications

References 18 publications

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Molecular - weight distribution in Graham's salt: Dependence on conditions of formation

Light-scattering studies on solutions of potassium-polyphosphate

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Polyphosphates as Polyelectrolytes. I. Light Scattering and Viscosity of Sodium Polyphosphates in Electrolyte Solutions1

Abstract: Several samples of sodium polyphosphate, covering a molecular weight range from 7000 t o 19000, were prepared by the condensation polymerization of primary sodium phosphate. The viscosity and PH of freshly prepared solutions decreased

Cited by 103 publications

References 18 publications

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Polyphosphate Binding and Chain Length Recognition ofEscherichia coli Exopolyphosphatase

Molecular - weight distribution in Graham's salt: Dependence on conditions of formation

Light-scattering studies on solutions of potassium-polyphosphate

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Polyphosphates as Polyelectrolytes. I. Light Scattering and Viscosity of Sodium Polyphosphates in Electrolyte Solutions¹