Search results for "Polyacrylamide Gel"
showing 10 items of 361 documents
Purification of Large Cytosolic Proteases for In Vitro Assays: 20S and 26S Proteasomes
2012
Proteasomes are the main cytosolic proteases responsible for generating peptides for antigen processing and presentation in the MHC (major histocompatibility complex) class-I pathway. Purified 20S and 26S proteasomes have been widely used to study both specificity and efficiency of antigen processing. Here, we describe the purification of active human 20S and 26S proteasomes from human erythrocytes by DEAE-ion exchange chromatography, ammonium sulfate precipitation, glycerol density gradient centrifugation, and Superose-6 size exclusion chromatography and their characterization using fluorogenic substrates and specific inhibitors.
DNA Evidence Uncompromised by Active Oxygen
2010
Currently, forensic sciences can make use of the potential of instrumental analysis techniques to obtain information from the smallest, even invisible, samples. However, as laboratory techniques improve, so too should the procedures applied in the search for and initial testing of clues in order to be equally effective. This requires continuous revision so that those procedures may resolve the problems that samples present. As far as bloodstains are concerned, there are methods available that are recognized as being both highly sensitive and effective. Nevertheless, the marketing of new cleaning products, those that contain active oxygen, has raised doubts about the ability of those procedu…
Haptoglobintypenbestimmung mittels vertikaler S�ulenelektrophorese in Polyacrylamidgel
1972
Ein kontinuierliches und zwei diskontinuierliche Polyacrylamidgelelektrophoreseverfahren zur Haptoglobintypendifferenzierung werden beschrieben und die Vorzuge dieser Technik den mit der Starkegelelektrophorese zu gewinnenden Ergebnissen gegenubergestellt. Alle 3 Verfahren sind fur die Routinediagnostik geeignet. Die kontinuierliche PAA-Gelelektrophorese bedeutet zwar eine geringe Vereinfachung der Methodik, sie ist aber den Disk-Verfahren hinsichtlich der Trennungsergebnisse des Hp-Bandenspektrums unterlegen.
Size measuring techniques as tool to monitor pea proteins intramolecular crosslinking by transglutaminase treatment
2015
International audience; In this work, techniques for monitoring the intramolecular transglutaminase cross-links of pea proteins, based on protein size determination, were developed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis profiles of transglutaminase-treated low concentration (0.01% w/w) pea albumin samples, compared to the untreated one (control), showed a higher electrophoretic migration of the major albumin fraction band (26 kDa), reflecting a decrease in protein size. This protein size decrease was confirmed, after DEAE column purification, by dynamic light scattering (DLS) where the hydrodynamic radius of treated samples appears to be reduced compared to the control o…
Characterization of two male-specific polypeptides in the tergal glands secretions of the cockroach Leucophaea maderae (Dictyoptera, Blaberidae)
1998
0965-1748 (Print) Journal Article Research Support, Non-U.S. Gov't; During the sexual behavior of cockroaches, the female mounts the courting male to feed on the proteinaceous secretion of the tergal glands. Polyacrylamide gel electrophoresis of male and female protein extracts after cuticle wiping revealed three major bands. Two of 18 and 22 kDa, named Lma-P18 and Lma-P22, are specific to the male tergal extracts. Moreover, Lma-P22 is only found in the male second tergite extracts. The third one of 54 kDa, named Lma-P54, is common to male and female extracts and could be considered as an ubiquitous surface protein. Several other minor proteins are also present on the body surface of adults…
Analysis of the TK enzyme complex induced by HSV types 1 and 2 by means of isoelectric focusing and polyacrylamide gel electrophoresis.
1982
Recently we have described that the Herpes simplex virus (HSV)-induced thymidine kinase (TK) induces AMP- and ADP-dThd-5'-phosphotransferase activities. We now demonstrate the heterogeneity of the described activities in isoelectric focusing experiments and polyacrylamide gel electrophoresis. A TK--mutant of HSV type 1 fails to induce these activities. The activities of the type 1 enzyme complex was neutralized by an anti-HSV-serum. The TK-enzyme complex expressed in LTK--cells transformed to a TK+-phenotype by sheared HSV-1 DNA was compared with the wild type TK complex in isoelectric focusing experiments. Additionally we demonstrate that the HSV type 1 enzyme complex has thymidylate kinas…
Construction of an agglutination tool: recombinant Fab fragments biotinylated in vitro.
2009
The pComb3H vector system is used for constructing and panning recombinant antibody libraries. It allows for expression of monovalent Fab fragments, either on the surface of M13 phage, or in the form of soluble proteins secreted into the periplasmic space of bacteria. We constructed a modified pComb3H vector containing cDNA encoding for a 23-amino acid fragment of the Escherichia coli biotin carboxy carrier protein (BCCP), which is an acceptor sequence for biotinylation. The vector was used to express the Fab fragment recognizing human glycophorin A. The purified Fab fragment containing this biotin acceptor sequence was effectively biotinylated in vitro using biotin ligase (BirA). The speci…
Mobility of Acetylated Histones in Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis
1999
Abstract We describe an altered mobility for acetylated histone isoforms in sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Isoforms of histones H3 and H4 with a higher acetylation degree have a slightly faster electrophoretic mobility. Since acetylation neutralizes the positive charge of the e-amino group of lysine, without significantly changing the molecular mass of the protein, the acetylation-dependent mobility shift could be explained by the increase of the net negative charge of the SDS–histone complexes. A possible consequence of this differential mobility for the acetylation site determination by protein microsequencing from SDS gels is discussed.
Exposure to malondialdehyde induces an early redox unbalance preceding membrane toxicity in human erythrocytes.
2002
This work investigated the oxidative injury to human red blood cells (RBCs) by the exposure to exogenous malondialdehyde (MDA), in a physiological environment. When a 10% RBC suspension was incubated in autologous plasma, in the presence of 50 microM MDA, 30% of MDA entered into the cells. A time-course study showed that MDA caused early (30-120 min) and delayed (3-18 h) effects. MDA caused a fast depletion of reduced glutathione, and loss of the glucose-6-phosphate dehydrogenase activity, followed by a decrease of HbO2. Accumulation of methemoglobin, and formation of small amounts of hemichrome were later evident. Also, an HbO2-derived fluorescent product was measured in the membrane. The …
Electrophoretic separation of a class of nucleosomes enriched in HMG 14 and 17 and actively transcribed globin genes.
1980
Monomer nucleosomes from chick erythrocytes can be fractionated according to their electrophoretic mobility in (comparatively) high salt acrylamide gels. We show that the fractionation is based predominantly on differences in charge. The monomer heterogeneity persists even when the nucleosomes are trimmed down to 145 bp with Exo III or when H1 and H5 are removed. The slowest migrating monomers are associated with HMG 14 and 17; however, we do not believe that these proteins are entirely responsible for the altered mobility since the nucleosome heterogeneity persists even after removal of HMG 14 and 17. The DNA associated with the HMG 14 and 17 containing nucleosomes is shown to be enriched …