Spectrin: Current understanding of its physical, biochemical, and functional properties

Kirkpatrick, Francis H.

doi:10.1016/0024-3205(76)90368-4

Cited by 120 publications

(43 citation statements)

References 106 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relationship to spectrin solubility is notable. At pH 6.30, puirified spectrini is mostly soluble aind at pH 5.32, spectrini is comiipletely precipitated after 60 mmin at 100,000 g (6,25,26 (Fig. 8).…”

Section: Resultsmentioning

confidence: 99%

“…But measurements of spectrin extraction from fresh and ATP-depleted ghosts as a function of extraction time showed that the decrease in spectrin extractability in the ATP-depleted sample, compared to normal, was evident throughout the extraction period. Extraction of spectrin from both samples reached a plateau by [20][21][22][23][24][25][26][27][28][29][30] h, well in advance of the time (40 h) when extractions were usually terminated (data not shown).…”

Section: Resultsmentioning

confidence: 99%

“…One interpretation of the previous results is that spectrin becomes inextractable in ATP-depleted erythrocytes because it aggregates and/or precipitates. Since spectriin also aggregates and precipitates at low pH (6,25,26) and at temperatures near 50(C (27, 28), we wondered if such precipitation would affect spectrin extractability and erythrocyte membrane deformability.…”

Section: Resultsmentioning

confidence: 99%

“…a pH where spectrin is aggregated and isoelectrically precipitated (6,25,26), erythrocyte deformability decreases and microspherocytes form coincident with a marked decrease in spectrin extractability (Fig. 7).…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Diminished spectrin extraction from ATP-depleted human erythrocytes. Evidence relating spectrin to changes in erythrocyte shape and deformability.

Lux¹,

John²,

Ukena³

1978

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T We measured spectrin "extractal)ilitvy in erythrocytes which were metabolically depleted ly ineubatioin at 37°C in plasma or glucose-free buffers. Membranes were extracted with 1 mnl EDTA (pH 8, 40 h, 4°C) 12 September 1977. exposed to extremes of pH and temlperature. WVhen the pH in the ervthrocvte interior fell below 5.5, a pH where spectrini was aggregated and isoelectricallv precipitated, erythrocyte and ghost viscosity increased coincident with a marked decrease in spectrini extractability. Similarly above 49°C, a temperatture where spectrin was denatured and precipitated, ervthrocvte viscosity rose as inextractable spectrin a(-cumulated. These observations provide direct evidence of a chanige in the physical state of spectrini associated with a change in ervthrocvte shape and deformability. They sutpport the concept that erythrocyte shape and deformability are largely determiined by the shape aind deformal)ilitv of the spectrin-actiii protein meshwork which laminates the inner membrane surface.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Diminished spectrin extraction from ATP-depleted human erythrocytes. Evidence relating spectrin to changes in erythrocyte shape and deformability.

Lux¹,

John²,

Ukena³

1978

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…Third, the RBC have a membrane skeleton located at the membrane-cytosal surface with its major component made of spectrin-actin (42,43) and this cystoskeletal network of the RBC participates in several membrane functions, including control of shape, viscoelastic properties, surface topology, and membrane stability (42)(43)(44) Since the osmotic fragility of a given RBC represents a measure of its surface area/volume ratio and since PTH did not affect water content of RBC, it is reasonable to suggest that the effect of the hormone on MOF is mediated through a reduction in surface area secondary to changes in cell membrane shape and/or integrity.…”

Section: Discussionmentioning

confidence: 99%

Effect of Parathyroid Hormone on Osmotic Fragility of Human Erythrocytes

Bogin¹,

Massry²,

Levi³

et al. 1982

J. Clin. Invest.

185

View full text Add to dashboard Cite

A B S T R A C T The survival of erythrocytes (RBC) is shortened in uremia, and it has been shown that calcium influx into RBC evoked crenation and increased their rigidity. The high blood levels of parathyroid hormone (PTH) may augment entry of calcium into RBC and hence affect their integrity. We examined the effect of PTH on osmotic fragility of human RBC and investigated the mechanisms through which PTH interacts with RBC. Both the amino-terminal (1-34) PTH and the intact (1-84) PTH, but not the carboxy-terminal (53-84) PTH, produced significant increases in osmotic fragility. This effect was abolished by prior inactivation of the hormone. There was a dose-response relationship between both moieties of PTH and the increase in osmotic fragility. This action of PTH required calcium, was mimicked by calcium ionophore, and was partially blocked by verapamil. PTH caused significant influx of 45Ca into RBC, which was not associated with potassium leak. The hormone did not affect water content of RBC. Scanning electron microscopy revealed that the incubation of RBC with PTH was associated with the appearance of membrane filamentous extensions, which anchor RBC together.Inhibition of glycolytic activity of RBC with NaF or inhibition of Na-K-activated ATPase with ouabain did not abolish the effect of PTH on osmotic fragility. PTH did not stimulate RBC Na-K-activated ATPase or Mg-dependent ATPase but caused marked and significant stimulation of Ca-activated ATPase. The basal activity of the RBC adenylate cyclase was low and PTH produced only a modest stimulation of this enzyme. Both cyclic AMP and dibutyryl cyclic AMP had no effect on osmotic fragility.The data indicate that: (a) the RBC is a target organ for PTH, (b) the hormone increases osmotic fragility

show abstract

Two‐dimensional polyacrylamide gel electrophoresis of water‐soluble erythrocyte membrane proteins

White

Ralston

1981

Electrophoresis

View full text Add to dashboard Cite

A method is reported for analyzing the oligomeric state of proteins in a mixture by multidimensional electrophoresis. Water-soluble proteins prepared from human erythrocyte membranes were separated by means of gel filtration followed by electrophoresis in detergent-free disc gels. The major bands in detergent-free disc gels were identified by means of electrophoresis into a second-dimensional slab gel containing sodium dodecyl sulphate. Detergent-free disc gels were also subjected to two-dimensional electrophoresis into detergent-free slab gels consisting of a continuous gradient of polyacrylamide gel. It was shown that many of the water-soluble proteins existed as distinct oligomers. Spectrin aggregates (tetramer and dimer) accounted for the slowest moving bands in the detergent-free disc gels. A watersoluble protein of the component 3 region appeared to be present as a hexamer, while component 4.1 was present as a tetramer. Components 4.3, 4.9 and 5 appeared to be present in a large number of aggregated states. Components 7 and 8 formed a heteropolymeric protein complex.

show abstract

Spectrin: Current understanding of its physical, biochemical, and functional properties

Cited by 120 publications

References 106 publications

Diminished spectrin extraction from ATP-depleted human erythrocytes. Evidence relating spectrin to changes in erythrocyte shape and deformability.

Diminished spectrin extraction from ATP-depleted human erythrocytes. Evidence relating spectrin to changes in erythrocyte shape and deformability.

Effect of Parathyroid Hormone on Osmotic Fragility of Human Erythrocytes

Two‐dimensional polyacrylamide gel electrophoresis of water‐soluble erythrocyte membrane proteins

Contact Info

Product

Resources

About