scholarly journals Nano Differential Scanning Fluorimetry-Based Thermal Stability Screening and Optimal Buffer Selection for Immunoglobulin G

2021 ◽  
Vol 15 (1) ◽  
pp. 29
Author(s):  
Soo Hyun Kim ◽  
Han Ju Yoo ◽  
Eun Ji Park ◽  
Dong Hee Na
Keyword(s):  
Thermal Stability ◽  
Immunoglobulin G ◽  
Sodium Acetate ◽  
Protein Unfolding ◽  
Sodium Citrate ◽  
Acetate Buffer ◽  
Sodium Acetate Buffer ◽  
Citrate Buffer ◽  
Protein Protein Interaction ◽  
Differential Scanning Fluorimetry

Nano differential scanning fluorimetry (nanoDSF) is a high-throughput protein stability screening technique that simultaneously monitors protein unfolding and aggregation properties. The thermal stability of immunoglobulin G (IgG) was investigated in three different buffers (sodium acetate, sodium citrate, and sodium phosphate) ranging from pH 4 to 8. In all three buffers, the midpoint temperature of thermal unfolding (Tm) showed a tendency to increase as the pH increased, but the aggregation propensity was different depending on the buffer species. The best stability against aggregation was obtained in the sodium acetate buffers below pH 4.6. On the other hand, IgG in the sodium citrate buffer had higher aggregation and viscosity than in the sodium acetate buffer at the same pH. Difference of aggregation between acetate and citrate buffers at the same pH could be explained by a protein–protein interaction study, performed with dynamic light scattering, which suggested that intermolecular interaction is attractive in citrate buffer but repulsive in acetate buffer. In conclusion, this study indicates that the sodium acetate buffer at pH 4.6 is suitable for IgG formulation, and the nanoDSF method is a powerful tool for thermal stability screening and optimal buffer selection in antibody formulations.

scholarly journals The recombination of dimers of immunoglobulin peptide chains

1970 ◽  
Vol 118 (5) ◽  
pp. 703-712 ◽  
Author(s):  
G. T. Stevenson ◽  
K. J. Dorrington
Keyword(s):  
Immunoglobulin G ◽  
Sodium Acetate ◽  
Optical Rotatory Dispersion ◽  
Acetate Buffer ◽  
Light Chains ◽  
Sodium Acetate Buffer ◽  
Covalent Bonds ◽  
Myeloma Protein ◽  
Disulphide Bonds ◽  
Antigenic Properties

1. Both the γ and light peptide chains of human pooled and myeloma immunoglobulin G can be prepared as non-aggregating dimers at pH5.4 in 4mm-sodium acetate buffer. The dimeric state is maintained by non-covalent bonds, since the formation of interchain disulphide bonds was prevented by alkylation of the thiol groups. In the case of the light chains there is some evidence that the dimers are in equilibrium with a small amount of monomer. 2. When such dimers of the γ and light chains are mixed at pH5.4 in 4mm-sodium acetate buffer they combine rapidly, yielding a product that resembles the original immunoglobulin G in its physicochemical and antigenic properties. However, the original optical rotatory dispersion spectrum was regained only with the homogeneous myeloma protein. The recombined pooled immunoglobulin G had a spectrum slightly different from the original, suggesting that at least some of the recombinant molecules had not regained native conformations. 3. Dimers of γ chains stabilized by interchain disulphide bonds were able to recombine with light chains. However, light chains stabilized in the dimeric state by interchain disulphide bonds would not combine with γ chains. 4. The chains of rabbit immunoglobulin G behave similarly to the human chains in this system, apart from the alkylated light chains showing clearer evidence of monomeric components.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

STARCH GEL ELECTROPHORESIS OF COBRA AND RATTLESNAKE VENOMS

1963 ◽  
Vol 41 (4) ◽  
pp. 1073-1078 ◽  
Author(s):  
J. M. Neelin
Keyword(s):  
Ionic Strength ◽  
Gel Electrophoresis ◽  
Sodium Acetate ◽  
Acetate Buffer ◽  
Starch Gel Electrophoresis ◽  
Two Dimensional ◽  
Sodium Acetate Buffer ◽  
Cacodylate Buffer ◽  
Starch Gel ◽  
Acidic Proteins

The effect of pH on gradient starch gel electrophoresis of the venoms of Crotalus adamanteus and Naja flava has been examined. Sodium acetate buffer, pH 4.1, ionic strength 0.020, appeared most effective for resolution of the former venom, and acetate buffer, pH 4.7, or cacodylate buffer, pH 6.0, for the latter. Two-dimensional starch gel electrophoresis resolved at least 20 zones from the crotaline venom and 11 from the colubrid. Two zones of hemolytic activity were separated from each venom: in C. adamanteus the less cationic zone included possibly two or more acidic proteins; the corresponding zone of N. flava was more basic, more homogeneous, and more active under the conditions of assay.

scholarly journals XRD Identification of Ore Minerals during Cruises: Refinement of Extraction Procedure with Sodium Acetate Buffer

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 160
Author(s):  
Jelena Milinovic ◽  
Ágata Alveirinho Dias ◽  
Ana I. Janeiro ◽  
Manuel F. C. Pereira ◽  
Sofia Martins ◽  
...  
Keyword(s):  
Sodium Acetate ◽  
Extraction Procedure ◽  
Xrd Analysis ◽  
Acetate Buffer ◽  
Sodium Acetate Buffer ◽  
Sediment Samples ◽  
New Information ◽  
Ore Minerals ◽  
Mid Atlantic Ridge ◽  
Seafloor Sediments

The on-board identification of ore minerals during a cruise is often postponed until long after the cruise is over. During the M127 cruise, 21 cores with deep-seafloor sediments were recovered in the Trans-Atlantic Geotraverse (TAG) field along the Mid Atlantic Ridge (MAR). Sediments were analyzed on-board for physicochemical properties such as lightness (L*), pH and Eh. Selected samples were studied for mineral composition by X-ray powder diffraction (XRD). Based on XRD data, sediment samples were separated into high-, low- and non-carbonated. Removal of carbonates is a common technique in mineralogical studies in which HCl is used as the extraction agent. In the present study, sequential extraction was performed with sodium acetate buffer (pH 5.0) to remove carbonates. The ratio between the highest calcite XRD reflection in the original samples (Iorig) vs its XRD-reflection in samples after their treatment with the buffer (Itreat) was used as a quantitative parameter of calcite removal, as well as to identify minor minerals in carbonated samples (when Iorig/Itreat > 24). It was found that the lightness parameter (L*) showed a positive correlation with calcite XRD reflection in selected TAG samples, and this could be applied to the preliminary on-board determination of extraction steps with acetate buffer (pH 5.0) in carbonated sediment samples. The most abundant minerals detected in carbonated samples were quartz and Al- and Fe-rich clays. Other silicates were also detected (e.g., calcic plagioclase, montmorillonite, nontronite). In non-carbonated samples, Fe oxides and hydroxides (goethite and hematite, respectively) were detected. Pyrite was the dominant hydrothermal mineral and Cu sulfides (chalcopyrite, covellite) and hydrothermal Mn oxides (birnessite and todorokite) were mineral phases identified in few samples, whereas paratacamite was detected in the top 20 cm of the core. The present study demonstrates that portable XRD analysis makes it possible to characterize mineralogy at cored sites, in particular in both low- and high-carbonated samples, before the end of most cruises, thus enabling the quick modification of exploration strategies in light of new information as it becomes available in near-real time.

SOME CHARACTERISTICS OF BRAIN TYROSINE HYDROXYLASE

1967 ◽  
Vol 45 (10) ◽  
pp. 1557-1563 ◽  
Author(s):  
E. G. McGeer ◽  
S. Gibson ◽  
P. L. McGeer
Keyword(s):  
Tyrosine Hydroxylase ◽  
Rat Brain ◽  
Phosphate Buffer ◽  
Sodium Acetate ◽  
Acetate Buffer ◽  
Sodium Acetate Buffer ◽  
Optimum Conditions ◽  
Hydroxylase Activity ◽  
Michaelis Constant ◽  
Brain Tyrosine Hydroxylase

Tyrosine hydroxylase from brain homogenates differed from tyrosine hydroxylase from adrenal homogenates in being particle-bound, insensitive to cofactors, possessing a lower Michaelis constant for tyrosine, and being responsive to slightly different optimum conditions of pH and buffer. The combination of 0.02 M mercaptoethanol and 0.1–1.0 mM 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine (DMPH4) increased tyrosine hydroxylase activity in beef adrenal homogenates 15-fold, but was without effect on activity in rat brain homogenates. The Km for tyrosine in beef adrenal homogenates was 4 × 10−6 M, and in rat brain homogenates was 0.45 × 10−6 M. Conversion in beef adrenal homogenates was maximum in 0.6 M sodium acetate buffer, pH 6.0, and in rat brain homogenates was maximum in 0.28 M phosphate buffer, pH 6.2.

Micro-scale method for theophylline in body fluids by reversed-phase, high-pressure liquid chromatography.

1977 ◽  
Vol 23 (3) ◽  
pp. 599-601 ◽  
Author(s):  
J J Orcutt ◽  
P P Kozak ◽  
S A Gillman ◽  
L H Cummins
Keyword(s):  
Sodium Acetate ◽  
Internal Standard ◽  
Peak Height ◽  
Reversed Phase ◽  
Acetate Buffer ◽  
Sodium Acetate Buffer ◽  
Serum Theophylline ◽  
Micro Scale ◽  
Scale Method ◽  
Standard Beta

Abstract We describe a micro-scale method for determining serum theophylline. The chromatography system includes a muBondapack C18 column and acetonitrile, 70 ml/liter of sodium acetate buffer (10 mmol/liter, ph 4.0) as the mobile phase. Test serum or plasma, 30 mul, is mixed with an equal quantity of a solution containing the internal standard, beta-hydroxyethyltheophylline in acetonitrile/sodium acetate buffer (20 mmol/liter, pH 4.0), 7/43 by vol. After the precipitate is removed by centrifugation, the mixture is chromatographed and the amount of theophylline calculated from the ratio between peak heights for theophylline and the internal standard. Advantages include easy sample preparation, involving only addition of internal standard and centrifugation before injection, long column life, and the suitability of the internal standard, which is adjusted to a peak height equivalent to 20 mg of theophylline per liter for easy computation of results.

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