scholarly journals IgG Charge

2018 ◽  
Author(s):  
Danlin Yang ◽  
Rachel Kroe-Barrett ◽  
Sanjaya Singh ◽  
Thomas Laue
Keyword(s):  
Negative Charge ◽  
Fundamental Property ◽  
Physiological Properties ◽  
Systematic Exploration ◽  
A Charge ◽  
Phosphate Buffered Saline ◽  
Thermodynamic Nonideality

It has been known since the 1930’s that all immunoglobulins carry a weak negative charge in physiological solvents. However, there has been no systematic exploration of this fundamental property. Accurate charge measurements have been made using membrane confined electrophoresis in two solvents (pH 5.0 and pH 7.4) on a panel of twelve mAb IgGs, as well as their F(ab’)2 and Fc fragments. The following observations were made at pH 5.0: 1) the measured charge differs from the calculated charge by ~40 for the intact IgGs, and by ~20 for the Fcs; 2) the intact IgG charge depends on both Fv and Fc sequences, but does not equal the sum of the F(ab)’2 and Fc charge; 3) the Fc charge is consistent within a class. In phosphate buffered saline, pH 7.4: 1) the intact IgG charges ranged from 0 to -13; 2) the F(ab’)2 fragments are nearly neutral for IgG1s and IgG2s, and about -5 for some of the IgG4s; 3) all Fc fragments are weakly anionic, with IgG1 < IgG2 < IgG4; 4) the charge on the intact IgGs does not equal the sum of the F(ab’)2 and Fc charge. In no case is the calculated charge, based on H+ binding, remotely close to the measured charge. The charge on IgGs in physiological solvent is sufficiently small to minimize its contribution to thermodynamic nonideality. Some of the mAbs carried a charge in physiological salt that was outside the range observed for serum-purified human poly IgG. To best match physiological properties, a therapeutic mAb should have a measured charge that falls within the range observed for serum-derived human IgGs.

scholarly journals IgG Charge: Practical and Biological Implications

Antibodies ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 24 ◽  
Author(s):  
Danlin Yang ◽  
Rachel Kroe-Barrett ◽  
Sanjaya Singh ◽  
Thomas Laue
Keyword(s):  
Negative Charge ◽  
Fundamental Property ◽  
Protein Protein Interaction ◽  
Physiological Properties ◽  
Systematic Exploration ◽  
Dependent Protein ◽  
Interaction Curves ◽  
A Charge ◽  
Phosphate Buffered Saline ◽  
Selection Of

Practically, IgG charge can contribute significantly to thermodynamic nonideality, and hence to solubility and viscosity. Biologically, IgG charge isomers exhibit differences in clearance and potency. It has been known since the 1930s that all immunoglobulins carry a weak negative charge in physiological solvents. However, there has been no systematic exploration of this fundamental property. Accurate charge measurements have been made using membrane confined electrophoresis in two solvents (pH 5.0 and pH 7.4) on a panel of twelve mAb IgGs, as well as their F(ab’)2 and Fc fragments. The following observations were made at pH 5.0: (1) the measured charge differs from the calculated charge by ~40 for the intact IgGs, and by ~20 for the Fcs; (2) the intact IgG charge depends on both Fv and Fc sequences, but does not equal the sum of the F(ab)’2 and Fc charge; (3) the Fc charge is consistent within a class. In phosphate buffered saline, pH 7.4: (1) the intact IgG charges ranged from 0 to −13; (2) the F(ab’)2 fragments are nearly neutral for IgG1s and IgG2s, and about −5 for some of the IgG4s; (3) all Fc fragments are weakly anionic, with IgG1 < IgG2 < IgG4; (4) the charge on the intact IgGs does not equal the sum of the F(ab’)2 and Fc charge. In no case is the calculated charge, based solely on H+ binding, remotely close to the measured charge. Some mAbs carried a charge in physiological salt that was outside the range observed for serum-purified human poly IgG. To best match physiological properties, a therapeutic mAb should have a measured charge that falls within the range observed for serum-derived human IgGs. A thermodynamically rigorous, concentration-dependent protein–protein interaction parameter is introduced. Based on readily measured properties, interaction curves may be generated to aid in the selection of proteins and solvent conditions. Example curves are provided.

A gel-membrane model of glomerular charge and size selectivity in series

2001 ◽  
Vol 280 (3) ◽  
pp. F396-F405 ◽  
Author(s):  
Maria Ohlson ◽  
Jenny Sörensson ◽  
Börje Haraldsson
Keyword(s):  
Negative Charge ◽  
Careful Analysis ◽  
Size Selectivity ◽  
Gel Structure ◽  
Experimental Conditions ◽  
Ion Interactions ◽  
In Series ◽  
A Charge ◽  
Glomerular Barrier

We have analyzed glomerular sieving data from humans, rats in vivo, and from isolated perfused rat kidneys (IPK) and present a unifying hypothesis that seems to resolve most of the conflicting results that exist in the literature. Particularly important are the data obtained in the cooled IPK, because they allow a variety of experimental conditions for careful analysis of the glomerular barrier; conditions that never can be obtained in vivo. The data strongly support the classic concept of a negative charge barrier, but separate components seem to be responsible for charge and size selectivity. The new model is composed of a dynamic gel and a more static membrane layer. First, the charged gel structure close to the blood compartment has a charge density of 35–45 meq/l, reducing the concentration of albumin to 5–10% of that in plasma, due to ion-ion interactions. Second, the size-selective structure has numerous functional small pores (radius 45–50 Å) and far less frequent large pores (radius 75–115 Å), the latter accounting for 1% of the total hydraulic conductance. Both structures are required for the maintenance of an intact glomerular barrier.

Preparation and Characterization of Surface Modified MCF (Mesostructured Cellular Foam) Silica for the Immobilization of Heteropolyacid Catalyst

2007 ◽  
Vol 119 ◽  
pp. 139-142
Author(s):  
Hee Soo Kim ◽  
Ji Chul Jung ◽  
Pil Kim ◽  
Kwan Young Lee ◽  
Sung Ho Yeom ◽  
...  
Keyword(s):  
Functional Group ◽  
Negative Charge ◽  
Positive Charge ◽  
Chemical Immobilization ◽  
Heteropolyacid Catalyst ◽  
Surfactant Templating ◽  
Amine Functional Group ◽  
A Charge ◽  
Surface Modified

Mesostructured cellular foam (MCF) silica was synthesized via surfactant templating route. The surface of MCF silica was then modified by grafting 3-aminopropyl-triethoxysilane (APTES) to have the positive charge, and thus, to provide sites for the immobilization of H3PMo12O40 (PMo12). By taking advantage of the overall negative charge of [PMo12O40]3-, PMo12 catalyst was chemically immobilized on the amine-functional group of surface modified MCF (SM-MCF) silica as a charge matching component. It was found that pore structure of MCF silica was maintained even after the surface modification and the subsequent immobilization of PMo12. It was also revealed that PMo12 species were finely and molecularly dispersed on the SM-MCF silica via chemical immobilization.

Electrostatic solitary structures in a charge-varying pair–ion–dust plasma

2007 ◽  
Vol 73 (3) ◽  
pp. 403-415 ◽  
Author(s):  
MOULOUD TRIBECHE ◽  
LEILA AIT GOUGAM ◽  
NADIA BOUBAKOUR ◽  
TAHA HOUSSINE ZERGUINI
Keyword(s):  
Negative Charge ◽  
Pulse Amplitude ◽  
Dusty Plasmas ◽  
Collisionless Shock ◽  
Electrons And Positrons ◽  
Solitary Structures ◽  
A Charge ◽  
Dust Grain ◽  
Grain Surface ◽  
Dust Plasma

AbstractLarge-amplitude electrostatic solitary structures are investigated in an unmagnetized charge-varying pair–ion–dust plasma in which electrons and positrons have equal masses. Their spatial patterns are significantly modified by the presence of the positron component. In particular, it may be noted that an addition of a small concentration of positrons abruptly reduces the potential pulse amplitude as well as the net negative charge residing on the dust grain surface. Under certain conditions, the solitary wave suffers the well-known anomalous damping leading to the development of collisionless shock waves. This investigation may be taken as a prerequisite for the understanding of the electrostatic solitary waves that may occur in space dusty plasmas.

Novel Hydroxyapatite-Polysaccharide Composite Microparticles for Immunotherapy

2014 ◽  
Vol 1626 ◽  
Author(s):  
Mitsuhiro Yoshida ◽  
Tomohiko Yoshioka ◽  
Toshiyuki Ikoma ◽  
Junzo Tanaka
Keyword(s):  
Electrostatic Interaction ◽  
Negative Charge ◽  
Positive Charge ◽  
Phosphoric Acid Solution ◽  
Precipitation Method ◽  
Carboxyl Group ◽  
Spray Dry ◽  
Release Property ◽  
Adsorption And Release ◽  
Phosphate Buffered Saline

ABSTRACTHydroxyapatite-chondroitin sulfate (HAp/ChS) composites were synthesized with calcium hydroxide suspension and phosphoric acid solution containing ChS through a precipitation method, and the microparticles were then fabricated by a spray dry method with the suspension of the composites. Bovine serum albumin (BSA) with negative charge or lysozyme (LYZ) with positive charge at pH7.0 was adsorbed onto the HAp/ChS microparticles. However, the HAp/ChS microparticles adsorbed LYZ more than the HAp microparticles compared with BSA due to the electrostatic interaction from negatively-charged sulfate or carboxyl group of ChS in the composites. The release property of BSA from the HAp/ChS microparticles was evaluated in Dulbecco’s phosphate buffered saline (pH7.2). The HAp/ChS microparticles released quickly 100% of the adsorbed BSA, while HAp microparticles released 45% of BSA. These results indicated that incorporation of ChS in the microparticles controls the adsorption and release properties of protein due to the electrostatic interaction. The HAp/ChS microparticles therefore are a candidate of a carrier for drugs like vaccines.

A theoretical study on the stereochemistry and protonation of −:CH2—NO2

1976 ◽  
Vol 54 (16) ◽  
pp. 2526-2533 ◽  
Author(s):  
P. G. Mezey ◽  
A. J. Kresge ◽  
I. G. Csizmadia
Keyword(s):  
Molecular Conformation ◽  
Theoretical Study ◽  
Negative Charge ◽  
Potential Surface ◽  
Population Analysis ◽  
Substantial Portion ◽  
Mulliken Population ◽  
Pyramidal Inversion ◽  
Pyramidal Configuration ◽  
A Charge

The molecular conformation of −:CH2NO2 is found to be planar with an extremely shallow potential curve to pyramidal inversion. This suggests that suitable substituents could conceivably perturb the System into a pyramidal configuration corresponding to double minimum on the potential surface and that a chiral carbanion might therefore exist. Rotating the NO2 group out of planarity by 90° raises the barrier to inversion at carbon by an appreciable amount.A Mulliken population analysis gives a charge distribution in which a substantial portion of the negative charge has shifted from carbon to oxygen; this is consistent with the well-known tendency of nitronate ions to undergo simultaneous competitive protonation on carbon and oxygen.

Surface charge characteristics of variable charge soils in Thailand

Soil Research ◽  
2010 ◽  
Vol 48 (4) ◽  
pp. 337 ◽  
Author(s):  
W. Wisawapipat ◽  
I. Kheoruenromne ◽  
A. Suddhiprakarn ◽  
R. J. Gilkes
Keyword(s):  
Organic Matter ◽  
Surface Charge ◽  
Negative Charge ◽  
Clay Fraction ◽  
Base Cation ◽  
Exchange Capacity ◽  
Rate Of Change ◽  
Phosphate Sorption ◽  
Variable Charge ◽  
A Charge

Surface charge characteristics were investigated using a charge fingerprinting procedure for 90 samples from 32 profiles of highly weathered Oxisols and Ultisols derived from shale/limestone, basalt, granite, local alluvium, sedimentary, and metasedimentary rocks under tropical savanna and tropical monsoonal climates in Thailand. The charge fingerprints of 5 whole soils, after removal of organic matter and of kaolin and ion oxides from these soils, were also measured to clarify factors contributing to the variable charge behaviour. Phosphate sorption was determined and related to charge properties. Kaolin was the dominant mineral of the clay fraction with moderate amounts of goethite and hematite. Gibbsite was present in Oxisols formed on limestone and basalt under more humid conditions. All soils exhibited variable charge behaviour but the magnitude and rate of change in variable charge with pH varied greatly between Oxisols and Ultisols. Oxisols had higher amounts of variable charge than Ultisols, reflecting the differences in amounts of clay and extractable Fe and Al. Oxisols formed on basalt and limestone under more humid conditions had high values of anion exchange capacity (AEC) due to the contributions of goethite, gibbsite, and boehmite. The relationships of base cation exchange capacity (CECB) and AEC with pH were linear. Rates of change with pH of both negative and positive variable charge (Ac, Aa) were closely related to CEC, specific surface area (SSA), pH(NaF), and various forms of extractable Fe, Al, and Mn. The charge fingerprints of soil after removal of organic matter indicated that organic matter exerted a strong influence on both the magnitude of negative charge and rate of change with pH. Kaolin had permanent and variable charge, with SSA and crystal size (MCD001) being highly predictive of the rate of change in variable negative charge with pH. Iron oxide concentrates exhibited strongly pH-dependent charge and the mean coherently diffracting length (MCD110) of hematite was highly predictive of both the magnitude and rate of change in variable positive charge with pH. Charge coefficients (Ac, Ba) had highly significant (P = 0.005) positive relationships with Langmuir and Freundlich phosphate sorption maximum coefficients (Xm, k), indicating that the surfaces of amorphous, poorly ordered, and crystalline Fe and Al oxides are prime sites for both P sorption and variable charge.

SOME QUALITATIVE RESULTS ON THE ELECTRIFICATION OF SNOW

1949 ◽  
Vol 27a (1) ◽  
pp. 1-8 ◽  
Author(s):  
B. W. Currie ◽  
D. C. Pearce
Keyword(s):  
Water Vapor ◽  
Space Charge ◽  
Laboratory Experiments ◽  
Negative Charge ◽  
Large Fraction ◽  
Space Charge Density ◽  
Positive Space Charge ◽  
Drifting Snow ◽  
A Charge ◽  
Positive Space

This paper reports on observations of the electrical charges on falling and drifting snow, and gives the results of laboratory experiments designed to determine the relative importance of possible charge-producing mechanisms in the atmosphere when snow and ice crystals are present. These mechanisms include impacts of snow particles on one another, melting of snow as it falls, and condensation of water vapor and formation of rime on falling snow. Apparently a large fraction of the snowflakes falling during the cold part of the winter in Saskatchewan has a charge less than 2 × 10−4 e.s.u. per flake. During blizzards the snow particles blowing along or just above the hard surface of the drifted snow carry a net negative charge and the air at the 1 m. level has positive space charge densities that are from 10 to 100 times the normal, positive space charge density. Very large charge separations can occur when a snow surface is eroded by an air blast and when snow is blown against snow and metal surfaces, a resultant negative charge appearing on the heavier particles and the corresponding positive charge on either very small ice particles or ions This charge-producing mechanism is most effective at high air velocities and at low temperatures The melting of newly fallen snow under conditions favorable to the escape of air bubbles does not show a charge separation. Condensation of water vapor and formation of rime on snow surfaces result in only very small charge separations for the conditions readily obtained in laboratory experiments

Changes in the surface charge of bacteria caused by heavy metals do not affect survival

1996 ◽  
Vol 42 (7) ◽  
pp. 621-627 ◽  
Author(s):  
Y. E. Collins ◽  
G. Stotzky
Keyword(s):  
Heavy Metals ◽  
Surface Charge ◽  
Negative Charge ◽  
Positive Charge ◽  
Agrobacterium Radiobacter ◽  
Charge Reversal ◽  
Ph Values ◽  
A Charge ◽  
Net Positive Charge ◽  
Cu And Zn

Bacillus subtilis and Agrobacterium radiobacter remained viable when exposed to Ni (1 × 10−4 M; ionic strength (μ) = 3 × 10−4) at pH values known to cause a change of the net negative charge of the cells to a net positive charge (charge reversal). The gross morphology, as determined by scanning electron microscopy, of these and other bacteria and of Saccharomyces cerevisiae was not altered in the presence of Ni, Cu, and Zn (1 × 10−4 M; μ = 3 × 10−4), which caused a charge reversal at pH values between 6.0 and 9.0. Similar results were obtained in the presence of Na and Mg, which did not cause charge reversal at the same μ and pH values. These results confirmed that cells remain viable when their surface charge is changed in the presence of some heavy metals at high pH values.Key words: heavy metals, electrokinetic properties, survival of bacteria.

The Fine Structure of Glycocalyx in Human Spermatozoa. A High Resolution Cytochemical Study

1973 ◽  
Vol 31 ◽  
pp. 640-641
Author(s):  
P. Hernández-Jáuregui ◽  
A. Sosa ◽  
A. González Angulo
Keyword(s):  
Negative Charge ◽  
Iron Hydroxide ◽  
Human Spermatozoa ◽  
Surface Coat ◽  
Cell Surfaces ◽  
Colloidal Iron ◽  
Cytochemical Study ◽  
Specific Permeability ◽  
Extracellular Glycoprotein ◽  
Mammalian Spermatozoa

Glycocalyx is the name given by Bennett to the extracellular glycoprotein coat present in some cell surfaces. It appears to play an important role in cell properties such as antigenicity, cell adhesivity, specific permeability, and ATP ase activity. In the sperm this coat can be directly related to such important phenomena as capacitation and fertilization. The presence of glycocalyx in invertebrate spermatozoa has already been demonstrated. Recently Yanagimachi et al. has determined the negative charges on sperm surfaces of mammalian spermatozoa including man, using colloidal iron hydroxide. No mention was made however of the outer surface coat as composed of substances other than those confering a negative charge. The purpose of this work was therefore to determine the presence of a glycocalyx in human spermatozoa using alcian blue and lanthanum staining.

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