摘要:

AbstractThe properties of pH gradients formed by stationary electrolysis of weak mobile or fixed electrolytes are analyzed. The model uses the appropriate balance equations and those of chemical equilibria. It is shown how the equation of the current density has to be modified for considering that fraction of current that is associated with the diffusion of neutral buffer molecules within a pH gradient. Furthermore it is shown that the pH gradients themselves give rise to water production within the gradient and that essential properties of the steady state are related to chemical reactions between the electrolyte constituents. The differential equations describing the gradients of the concentration of a given component, the pH, conductivity and potential are explicitly formulated in relation to those reactions. The equations are solved numerically and the significance of the results for isoelectric focusing is discussed. The experimental conditions to reach shallow and smooth pH gradients exhibiting sufficient ionic strength are formulated.

ISSN:0173-0835    

DOI:10.1002/elps.1150110402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA method of electrophoresis in an expanded stationary boundary is described, in which a pH gradient formed in a single buffer is used. The degrees of ionization and the concentrations of the electrolytes have values at which the polyions stack and resolve simultaneously in a polyacrylamide gel. To illustrate the method, the resolving of serum proteins in a pH gradient formed by Tris – glycinate buffer is considere

ISSN:0173-0835    

DOI:10.1002/elps.1150110403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe isotachophoretic behavior of serum albumin is examined for three anionic and one cationic electrolyte systems by (i) computer simulation, (ii) capillary isotachophoresis (ITP) and (iii) continuous flow ITP. The theoretical relationship between pH of the leading electrolyte and the steady state protein plateau concentration is presented for one of the anionic systems. With leading ion concentrations of the order of 10 mm, experimental protein plateau concentrations of 1.3–2.3 % w/v are obtained. The computer predictions are approximately half these value

ISSN:0173-0835    

DOI:10.1002/elps.1150110404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe isotachophoretic behavior of a model protein, serum albumin, was examined (i) by computer simulation, (ii) by capillary isotachophoresis in HPE 100 and Tachophor 2127, (iii) by continuous flow isotachophoresis in Elphor VaP 22 and the BIO‐STREAM Separator and (iv) by recycling isotachophoresis in an apparatus of our own design. Variations in monitored zone shapes can be explained by differences in engineering aspects and fluid stabilization principles of the instrument

ISSN:0173-0835    

DOI:10.1002/elps.1150110405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe principles and some applications of free flow zone electrophoresis and isotachophoresis are described. The influence of (i) carrier electrolyte conductivity on the migration velocity and (ii) band shape on zone electrophoresis was investigated. The technique was found convenient for studying the effect of pH on the mobility of proteins to create a mobility curve. The purification of alcohol dehydrogenase from a crude yeast extract revealed the separation power of zone electrophoresis for complex protein mixtures. Without additional steps, a purification factor of 5.4, with a recovery of 97 % alcohol dehydrogenase, was achieved. Free flow isotachophoresis was applied to the purification of immunoglobulins from human serum. Disadvantages of this technique are the time‐consuming development of an optimized separation system and the empirical search for suitable spacers. Also, reaching of the steady state becomes increasingly difficult as the number of sample components increase

ISSN:0173-0835    

DOI:10.1002/elps.1150110406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractGliadins, defined as wheat kernel storage proteins soluble in 70% ethanol, possess an electrophoretic diversity permitting us to identify different varieties. Because of genetic proximity, however, it sometimes proves impossible to distinguish between different varieties using standard methods. An electrophoresis method, utilizing a discontinuous buffer system with aluminum lactate and potassium lactate in the gel and sodium lactate in the electrode vessels, is described for two types of gels 18 cm and 32 cm in length. The number of bands in higher than with standard methods, and is significantly increased with long gels, facilitating the distinction between varieties. A nomenclature for the new bands is presented for several widely different cultivars.

ISSN:0173-0835    

DOI:10.1002/elps.1150110407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA new and simplified procedure is described for apolipoprotein E (APO E) phenotyping from native plasma or serum samples. Diluted or dialyzed samples are separated on agarose isoelectric focusing gels followed by protein blotting on nitrocellulose membranes. APO E banding patterns are localized immunologically using polyclonal goat anti‐APO E antiserum as the primary antibody and rabbit anti‐goat IgG conjugated with alkaline phosphatase as the secondary antibody. The method was used in parallel with our previously described polyacrylamide gel system to screen 110 unrelated and healthy US whites. Both gel systems gave identical APO E phenotypes, and allele frequencies were comparable with reported US white values. This simplified method can be used on a large number of population and clinical samples with minimum cost and eff

ISSN:0173-0835    

DOI:10.1002/elps.1150110408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractPhenotyping of erythrocyte acid phosphatase (EAP) and esterase D (ESD) by cellulose acetate membrane isoelectric focusing (CAM‐IEF) under a nonequilibrium condition is described. In an attempt to improve the method of CAM‐IEF, we shortened the electrode distance to provide a higher field strength at a given (low) voltage. Various carrier ampholytes for EAP typing and various chemical separators for ESD typing were also tested. Good separations were obtained after 30 min IEF for EAP typing and 25 min for ESD typing. When applied to blood stains and stored for various periods at room temperature, the stains up to 8 months old could still be phenotyped for EAP and those up to 4 weeks old for ESD. CAM‐IEF is suitable for routine forensic work of EAP and ESD phenot

ISSN:0173-0835    

DOI:10.1002/elps.1150110409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA fast isoelectric focusing method for routine haptoglobin (Hp) subtyping is presented. This method is based on isoelectric focusing, under reducting conditions, of neuraminidase‐treated plasma samples by using dry miniaturized (interelectrode distance: 55 mm) polyacrylamide gel, rehydráted in presence of 2‐mercaptoethanol and a mixture of pharmalyte carrier ampholytes (pH 4–6.5 and pH 6–8) followed by immunoblotting. The presence of 2‐mercaptoethanol in the gel prevented refolding of the Hp α and Hp β chains during focusing, making it possible to obtain a sharp Hp band pattern with a clear separation of the different Hp α allelic products (1S, 1F, 2FS, 2SS and 2FF). A population study carried out with 250 unrelated individuals living in Central Spain is a

ISSN:0173-0835    

DOI:10.1002/elps.1150110410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractPrevious studies using two‐dimensional gel electrophoresis have described adult and fetal isoforms of skeletal muscle myosin light chains (MLC). They have also revealed an embryo‐specific light chain (LC1emb), apparently absent in most adult skeletal muscles. In order to characterize more thoroughly the MLC family, we have analyzed the MLCs from human skeletal muscle at different developmental stages using a two‐dimensional electrophoresis technique with an immobilized pH gradient in the first dimension. The high resolution of this novel technique, resolving components which in isoelectric points are ≤ 0.01 pH, combined with sensitive silver staining, has allowed us to identify four phosphorylatable isoforms of MLC2: two slow‐myosin light chains (MLC2Sa and b), two fast myosin light chains (MLC2:a and b), and their phosphorylated counterparts: MLC2SaP and bP, MLC2FaP and bP. The following major modifications during development were observed: (i) The embryonic LC (LC1emb) persists up to at least 26 weeks of fetal life. (ii) The polymorphism of LC2 is already evident at 10 weeks of development but only the nonphosphorylated forms of LC2S and LC2F seem to be present. The LC2Fa form is predominant. As early as 26 weeks of fetal life, the 4 phosphorylated forms are detected. In the adult, LC2Fb is a minor component. (iii) LC3F (fast) is already expressed at an early embryonic stage (

ISSN:0173-0835    

DOI:10.1002/elps.1150110411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY