scholarly journals Combination of strong anion exchange liquid chromatography with microchip capillary electrophoresis sodium dodecyl sulfate for rapid two-dimensional separations of complex protein mixtures

Author(s):  
Holger Zagst ◽  
Christin Elgert ◽  
Sönke Behrends ◽  
Hermann Wätzig

AbstractTwo-dimensional separations provide a simple way to increase the resolution and peak capacity of complex protein separations. The feasibility of a recently developed instrumental approach for two-dimensional separations of proteins was evaluated. The approach is based on the general principle of two-dimensional gel electrophoresis. In the first dimension, semi-preparative strong anion exchange high-performance liquid chromatography is utilized and fractions are collected by means of a fraction collector. They are subsequently analyzed in the second dimension with microchip capillary electrophoresis sodium dodecyl sulfate. Microchip capillary electrophoresis provides the necessary speed (approximately 1 min/fraction) for short analysis. In this study, three different samples were investigated. Different constructs of soluble guanylyl cyclase were expressed in Sf9-cells using the baculovirus expression system. Cell lysates were analyzed and the resulting separations were compared. In our experimental setup, the soluble guanylyl cyclase was identified among hundreds of other proteins in these cell lysates, indicating its potential for screening, process control, or analysis. The results were validated by immunoblotting. Samples from Chinese hamster ovary cell culture before and after a purification step were investigated and approximately 9% less impurities could be observed. The separation patterns obtained for human plasma are closely similar to patterns obtained with two-dimensional gel electrophoresis and a total of 218 peaks could be observed. Overall, the approach was well applicable to all samples and, based on these results, further directions for improvements were identified. Graphical abstract .

1982 ◽  
Vol 28 (4) ◽  
pp. 908-914 ◽  
Author(s):  
R P Tracy ◽  
R M Currie ◽  
D S Young

Abstract Currently we are using two different ISO-DALT two-dimensional gel electrophoresis systems, designated MC-Iso 1 and MC-Iso 2, for the analysis of serum and plasma samples. Here we report quality-assurance data for both of these systems. CV values for the slopes of the pH gradient (ISO dimension) are 5.6% of less; CV values for the slopes of the molecular-mass curves (log Mr vs relative mobility in the DALT dimension) are 3.4% or less. We examined the various steps of the analysis in detail for reproducibility and protein loss, using radiolabeled albumin, alpha 2-macroglobulin, and beta 2-microglobulin. Generally, in the first dimension, less protein enters the MC-Iso 2 gels (our routine system in which silver stain is used) than enters the MC-Iso 1 gels (our wide-range system for myeloma serum samples, in which the gel is stained with Coomassie Blue), on the average, 87% as much. The CV at this stage for both systems is 5--8%. During equilibration, considerable amounts of protein are lost (approximately 30% in 10 min) from the ISO gel, and the reproducibility is also decreased. Resolution in the DALT dimension has, in most cases, little or no effect on either recovery or reproducibility. Overall, for most proteins expected to appear in an ISO gel of a given pH range, approximately 50--60% of the starting material may be expected to reside in the sodium dodecyl sulfate slab gel, under our conditions. The two most important variables affecting recovery are the concentration of the NaOH (used as catholyte) and the pH of the starting sample. The overall CV for the process is between 8 and 12%.


1977 ◽  
Vol 146 (5) ◽  
pp. 1261-1279 ◽  
Author(s):  
P P Jones

Mouse lymphocyte H-2 and Ia glycoproteins have been analyzed with a two-dimensional (2-D) acrylamide gel electrophoresis technique, in which proteins are separated first according to their charge in isoelectrofocusing gels and then according to their size in sodium dodecyl sulfate gels. Individual polypeptide chains from radiolabeled cells are resolved as discrete spots on autoradiograms of the gels, forming patterns which are characteristic of the proteins in the sample. 2-D gels of H-2K, H-2D, and Ia glycoproteins immunoprecipitated from 35S-methionine-labeled cells reveal that these proteins exist in the cells as complex arrays of molecules heterogeneous in both size and charge. Lactoperoxidase-catalyzed radioiodination of lymphocyte surfaces labels only subsets of the total H-2 and Ia molecules with 125I, indicating that some of the molecules may represent cytoplasmic precursors of the cell surface proteins. This theory is supported by the kinetics of labeling of various spots in 35S-methionine pulse-chase experiments. The 2-D gel patterns obtained for both H-2 and Ia antigens have also been shown to be haplotype-specific and independent of the genetic background.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Areeba Ahmad ◽  
Riaz Ahmad

AbstractTwo-dimensional gel electrophoresis (2DE) separating proteins on the basis of their pI and molecular mass remain the best available technique for protein separation and characterization to date. But due to several limitations, including streak formation in IEF gels, partial solubility of proteins, expensive running conditions and relatively longer time taken, a simple urea-SDS-2D polyacrylamide gel electrophoresis (US2DE) is described here. The system is reasonably sensitive, cost effective with good reproducibility. The method described in this paper employs a chaotropic agent, urea, in the first dimension and sodium dodecyl sulphate (SDS), like conventional system, in the second dimension with an addition of polyacrylamide to screen the liver proteome of healthy and chemically induced fibrotic rats. The system separates the protein on the basis of chargeto- mass ratio and clearly demonstrates differential expression in the liver protein repertoire of healthy and fibrotic rats. Moreover, the present system, like other 2D electrophoretic procedures revealed at least 22 novel spots in the investigated tissues. The technique may be utilized for comprehensive proteome screening of any biological sample and would provide an overview to narrow down the candidate proteins or biomarkers.


1980 ◽  
Vol 26 (9) ◽  
pp. 1317-1322 ◽  
Author(s):  
D Goldman ◽  
C R Merril ◽  
M H Ebert

Abstract Two-dimensional electrophoresis, with isoelectric focusing in the first dimension and sodium dodecyl sulfate/polyacrylamide gel electrophoresis in the second, has been adapted for the high-resolution analysis of cerebrospinal fluid proteins. Proteins were detected with a new, highly sensitive silver stain that made visible more than 300 polypeptides from 60 microL of spinal fluid, in highly reproducible patterns. We have mapped these patterns, noting difference between the proteins observed in spinal fluid and plasma, and have prepared a partial map of cerebrospinal fluid proteins.


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