Electrokinetic Phenomena

Abramson, Harold A.

doi:10.1085/jgp.15.5.575

Cited by 42 publications

(16 citation statements)

References 12 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence some mechanism seems to exist, capable of stabilizing the charge per unit area, within limits, while the surface undergoes comparatively marked changes in area and shape. The conditions which must be satisfied to establish the identity of two surfaces have been discussed before (9).…”

Section: Resultsmentioning

confidence: 99%

The Electrical Charge of Mammalian Red Blood Cells

Abramson

Moyer

1936

Journal of General Physiology

Self Cite

View full text Add to dashboard Cite

From data on the surface area and electrical mobilities of mammalian red blood cells in M/15 phosphate buffer at pH 7.4, it has been possible, with the help of the Gouy and von Smoluchowski theories, to calculate the net surface charge per cell as well as the charge per unit area. It was found that a single mammalian red cell has a net surface charge ranging from four to fifteen million electrons, depending on the species. No clear relationship between zoological classification and surface charge is apparent. It is suggested that a mechanism exists which is capable of keeping the surface density of net charge constant when comparatively large changes in surface area occur in the anemias.

show abstract

Section: Resultsmentioning

confidence: 99%

The Electrical Charge of Mammalian Red Blood Cells

Abramson

Moyer

1936

Journal of General Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…TEXT Adsorption phenomena and, in particular, protein adsorption have been studied for more than a century. 1,2 Recently, protein adsorption has regained importance due to the development of nanoscience and nanotechnology, [3][4][5] and the subsequent manufacture of large amounts of engineered nanomaterials. Their applications are numerous in the environmental, agri-food, health, and pharmaceutical sectors.…”

Section: Tocmentioning

confidence: 99%

From Protein Corona to Colloidal Self-Assembly: The Importance of Protein Size in Protein–Nanoparticle Interactions

et al. 2020

View full text Add to dashboard Cite

Protein adsorption on nanoparticles is an important field of study, particularly with regard to nanomedicine and nanotoxicology. Many factors can influence the composition and structure of the layer(s) of adsorbed proteins, the so-called protein corona. However, the role of protein size has not been specifically investigated, although some evidence has indicated its potential important role in corona composition and structure. To assess the role of protein size, we studied the interactions of hemoproteins (spanning a large size range) with monodisperse silica nanoparticles. We combined various techniquesadsorption isotherms, isothermal titration calorimetry, circular dichroism, and transmission electron cryomicroscopyto address this issue. Overall, the results show that small proteins behaved as typical model proteins, forming homogeneous monolayers on the nanoparticle surface (protein corona). Their adsorption is purely enthalpy-driven, with subtle structural changes. In contrast, large proteins interact with nanoparticles via entropy-driven mechanisms. Their structure is completely preserved during adsorption, and any given protein can directly bind to several nanoparticles, forming bridges in these newly formed protein–nanoparticle assemblies. Protein size is clearly an overlooked factor that should be integrated into proteomics and toxicological studies.

show abstract

“…After the net charge of the protein is obtained, within the limits indicated above, it is then possible to compare these values with those obtained from the interpretation of titration data and of membrane potential measurements. As has been the experience of Abramson (1,12), Moyer and Abels (3), Longsworth (5), and Cannan, Palmer, and Kibrick (6), reached on the basis of more approximate solutions of the Debye-Hfickel differential equation, we too find that 1 Recently, Tiselius and Svensson (11) have claimed that the simple Debye-Hfickel theory can be successfully used over a wide range of ionic strengths to calculate the electrophoretic mobility from the net charge estimated by measurements of membrane potentials. See, however, Gorin (10) and Longsworth (5).…”

Section: Theoreticalmentioning

confidence: 90%

“…For the systems to be presented here, the Gronwall-La Mer effect may be neglected. 1 The theory to be outlined below applies equally well to protein systems made up of molecules that all have the same charge at any instant or to systems in which the charge of the molecules fluctuates rapidly with time. In the latter case, the net charge determined by electrophoresis is the charge taken over a time average.…”

Section: Theoreticalmentioning

confidence: 99%

“…In this case, g = 12.75 v for a sphere or 13.94 v for a rod. Carman, Palmer, and Kibrick present two sets of titration data for this protein: (1) in the presence of various concentrations of salt at a protein concentration of 0.5 per cent and (2) at various concentrations of protein in the absence of added salt. A curve representing the titration curve at infinite dilution of electrolytes and protein has been obtained by extrapolation of this latter set of results ( Fig.…”

Section: Serum Albumin--inmentioning

confidence: 99%

See 1 more Smart Citation

The Valence of Corpuscular Proteins

Gorin

Mover

1942

Journal of General Physiology

View full text Add to dashboard Cite

The quantity most directly related to the net charge or valence of corpuscular proteins is the electrophoretic mobility. In 1932 Abramson (1) showed that in solutions of the same ionic strength the electric mobility of the same protein at different hydrogen ion activities is directly proportional to the number of hydrogen ions bound or released as determined by titration curves. His comparisons were made with gelatin, serum albumin, egg albumin, and casein. The generality of Abramson's rule has been confirmed by Daniel (2), Moyer and Abels (3), Moyer and Abramson (4), Longsworth (5), and also by Carman, Palmer, and Kibrick (6). Longsworth's data on egg albumin are especially interesting, for his comparison extends from pH 3 to 12. Inasmuch as the results of Abramson and of Moyer seem to have been misunderstood, it should be emphasized that they deal with comparisons of data on dissolved proteins. If the protein in the adsorbed state happens to agree, it is incidental to the argument.Not only did Abramson show proportionality between the electric mobility and titration curves, but he also attempted to calculate the valence of proteins from the available electrophorefic and titration data. The agreement, however, was incomplete.Although acid-base titration and membrane potential measurements on protein solutions give results that are related to the electric mobility, the actual determination of the net charge from these measurements is subject to difficulties in interpretation and questionable assumptions. On the other hand, an exact interpretation of electric mobility data in terms of net charge requires independent information concerning the size and shape of the protein molecule and the sizes of the other ions in the solution. Information regarding size and shape is not yet available for any protein. Extreme limits of variation of these quantities, however, may be obtained from sedimentation and diffusion data by the assumption, on the one hand, of spherical shape and enough hydration, or, on the other, of enough asymmetry, to account for the diffusion constant.The results presented in this communication indicate that when these factors are taken into account, values for the valence calculated from titration, electro-* This work was aided, in part, by a grant made to one of us (L. S. M.) by the

show abstract

Electrokinetic Phenomena

Cited by 42 publications

References 12 publications

The Electrical Charge of Mammalian Red Blood Cells

The Electrical Charge of Mammalian Red Blood Cells

From Protein Corona to Colloidal Self-Assembly: The Importance of Protein Size in Protein–Nanoparticle Interactions

The Valence of Corpuscular Proteins

Contact Info

Product

Resources

About