Electrophoresis characterization

Structural Analyses of Hemoglobin Variants It has become Impossible to characterize nearly any abnormal hemoglobin by Its electrophoretic and/or chromatographic mobility only This Is most strikingly demonstrated by the fact that over fifty different variants behave similar to Hb-S In electrophoresis Characterization, therefore, often requires detailed structural analyses or the demonstration of a property unique to a specific variant Some of the techniques used In these studies will be... 

Figure 10 Capillary electrophoresis characterization of the composite nature of sulfobuty-lether7 (SBE7)- 3-cyclodextrin CD. Roman numerals indicate the degree of substitution of each SBE band (I = SBEl-fi-CD,. .., IX = SBE9-fi-CD).

Table 1 The Four Main Modes of Capillary Zone Electrophoresis, Characterized by the Signs and Limiting Values of the Key Migration Parameters3...

Svendsen, P. J. and Axelsen, N. H. A. (1972) A modified antigen-antibody crossed electrophoresis characterizing the specificity and titre of human precipitins agamst Candxda albicans. J. ImmuncL Methods 1,169-176. 

Ramshy, M. L., Makowski, G. S., and KhairaUah, E. A., Differential detergent fractionation of isolated hepatocytes Biochemical, immunochemical and two-dimensional gel electrophoresis characterization of cytoskeletal and noncytoskeletal compartments. Electrophoresis, 15, 265-277,1994. 

Mohna, E. Frutos, M. Ramos, M. Capillary electrophoresis characterization of the casein fraction of cheeses made from cows , ewes and goats milks. J. Daily Res. 2000,67,209-216. 

Zhang C, Tomalia DA (2001) Gel electrophoresis characterization of dendritic polymers. In Frechet JMJ, Tomalia DA (eds) Dendrimers and other dendritic polymers. Wiley, Chichester, pp 239-252... 

Other important characterization techniques include electrophoresis measurements of droplets [11, 12] (see Section XIV-3C), infrared absorption of the constituent species [13], and light or x-ray scattering. NMR self-diffusion measurements can be used to determine droplet sizes in W/0 emulsions [14]. 

Efficiency The efficiency of capillary electrophoresis is characterized by the number of theoretical plates, N, just as it is in GC or ITPLC. In capillary electrophoresis, the number of theoretic plates is determined by... 

Biomolecule Separations. Advances in chemical separation techniques such as capillary zone electrophoresis (cze) and sedimentation field flow fractionation (sfff) allow for the isolation of nanogram quantities of amino acids and proteins, as weU as the characterization of large biomolecules (63—68) (see Biopolymers, analytical techniques). The two aforementioned techniques, as weU as chromatography and centrifugation, ate all based upon the differential migration of materials. Trends in the area of separations are toward the manipulation of smaller sample volumes, more rapid purification and analysis of materials, higher resolution of complex mixtures, milder conditions, and higher recovery (69). 

Anhydrotetracycline oxygenase from Streptomjces aureofaciens which cataly2es the conversion of anhydrotetracycline to dehydrotetracycline, has been isolated and characterized as a flavin-dependent oxygenase (83). It consists of two subunits of mol wt = 57, 500 based on SDS/polyacrylamide—gel electrophoresis. The cosynthetic factor 1 of Streptomjces aureofaciens involved in the reduction of 5a,lla-dehydrochlortetracycline to chlortetracycline, has been identified as 7,8-didemethyl-8-hydroxy-5-deazariboflavin. This work was aided by comparison of spectral data with that of an authentic sample obtained from the hydrolysis of coenzyme F-420 (84). 

Polyacrylamide gel electrophoresis is one of the most commonly used electrophoretic methods. AnalyMcal uses of this technique center around protein characterization, for example, purity, size, or molecular weight, and composition of a protein. Polyacrylamide gels can be used in both reduced and nonreduced systems as weU as in combination with discontinuous and ief systems (39). 

Each amino acid is characterized by an isoelectric point , the pH at which it exists in neutral form. Differences in isoelectric points may be exploited to separate amino acids in what is termed an electrophoresis experiment. 

Classical gel electrophoresis has been used extensively for protein and nucleic acid purification and characterization [9, 10], but has not been used routinely for small molecule separations, other than for polypeptides. A comparison between TLC and electrophoresis reveals that while detection is usually accomplished off-line in both electrophoretic and TLC methods, the analyte remains localized in the TLC bed and the mobile phase is immediately removed subsequent to chromatographic development. In contrast, in gel electrophoresis, the gel matrix serves primarily as an anti-... 

The refinement of other analytical methods, such as electrophoresis [34,36], the various techniques of optical spectroscopy [103-105], and nuclear magnetic resonance [201], is supplemented by the recent advances in real-time affinity measurements [152,202], contributing to the understanding of biomolecular reactivity. Taken together, the improvement of analytical methods will eventually allow a comprehensive characterization of the structure, topology, and properties of the nucleic acid-based supramolecular components under consideration for distinctive applications in nanobiotechnology. 

The, chain voAiantS are characterized by the presence of two abnormal components, an abnormal Hb-F (02 /2) and an abnormal Hb-A (tt2 32) Of these two, the 02 2 component dominates and the 02 32 component Is often difficult to detect. The methods of choice are starch gel electrophoresis and anion-exchange chromatography using DEAE-Sephadex or DE-52 Cellulose. Chain analyses of these Isolated hemoglobin components will lead to a definitive Identification. 

Hutton, T. and Major, H.J., Characterizing biomolecnles by electrospray ionization-mass spectrometry coupled to liqnid chromatography and capillary electrophoresis, Biochem. Soc. Trans., 23, 924, 1995. 

Very recently, HPLC with fluorescence detection was recommended for improving detection sensitivities of betalains. " While this technique may be worthwhile for betaxanthin analyses, its use for betacyanins cannot be recommended. Although this technique represents a worthwhile approach requiring low amounts of solvent and sample and generally characterized by a high separation efhciency, only one study dealt with the use of capillary zone electrophoresis for betalain analyses. ... 

Carmine extracted from cochineal insects is one of the most used natural colorings for beverages and other foods. Some representative articles refer to isolation and spectrometric analysis or the use of HPLC or capillary electrophoresis (CE) to separate and characterize all cochineal pigments. Its active ingredient, carminic acid, was quantified by rapid HPLC-DAD or fluorescence spectrometry. Carminic acid, used as an additive in milk beverages, was separated within 9 min using a high-efficiency CE separation at pH 10.0 after a previous polyamide column solid phase extraction (SPE), ... 

For CBCA synthase hardly any information has been pubhshed. The enzyme was characterized after it was purified from C. sativa extracts and until this moment no sequence has been deposited. After purification of the protein it was found to be a homodimeric enzyme, meaning that enzyme is formed by two identical domains. This was observed after the purification, when the enzyme had a molecular weight of 136 kDa, and after denatured electrophoresis, when it had a molecular weight of 71 kDa. Furthermore, the CBCA synthase has shown to bear higher affinity for CBGA (1717 M S ) than THCA synthase and CBDA synthase (respectively 1382M s and 1492 M s ), which is probably due to its homodimeric nature [40]. 

Marshall, T. and Williams, K. M. (1987). Electrophoresis of honey Characterization of trace proteins from a complex biological matrix by silver staining. Anal. Biochem. 167,301-303. 

R. Sen and C. M. Hepper, Characterization of vesicular-arbu.scular mycorrhizal fungi (Glomus spp.) by. selective enzyme staining following polyacrylamide gel electrophoresis. Soil Biol. Biochem. 18 29 (1996). 

These assumptions were confirmed by the electrophoresis study of the washed creams. Electrophoresis of purified fat globules is a convenient method to characterize and quantify proteins adsorbed at the oil-water interface [35]. Electrophoretic data indicate that no casein, nor whey proteins, were adsorbed at the surface of raw-milk fat globule. Upon homogenization, caseins adsorbed preferentially at the lipid-water interface. In this case, bound a-lactalbumin accounted for 16% of the total interfacial proteins. Heat treatment also induced the interaction of proteins with the fat globules. The amount of bound proteins (per mg of lipids) for heated raw milk was half that for homogenized milk. 

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