Search results for "Gel electrophoresi"
showing 10 items of 321 documents
On-line coupling of gel electrophoresis and inductively coupled plasma-sector field-mass spectrometry for the determination of dsDNA fragments.
2005
The on-line coupling of gel electrophoresis (GE) and inductively coupled plasma-mass spectrometry (ICPMS) is described for the first time. The new method combines the separation power of GE for large biomolecules and the high sensitivity and elemental selectivity of ICPMS. This coupling has been achieved by means of gels housed in glass tubes (length 2.5-20 cm; i.d. 0.5-5 mm). The gel is fixed by glass frits permeable for the analytes. After the electrophoretic separation at voltages up to 500 V, the analytes are transferred to the nebulizer of the ICPMS by an eluent stream, which is separated from the electrode chamber by a membrane. This filter blocks molecules with molecular masses large…
Analytical technique for studying the structure of glycoprotein N-glycans
1993
Abstract The aim of this study was to develop an analytical strategy for the structural analysis of glycoprotein N-glycans by combining several sensitive methods without any elaborate equipment. The following consecutive steps were optimized and applied: (1) immobilization of glycopeptide N-glycosidase F (EC 3.2.2.18) on several polymeric and a silica support, the latter giving a maximum binding capacity of 11.3% of starting activity; (2) lectin affinity chromatography was miniaturized using Mobitec columns of volume 200 μl; the binding capacity of glycoproteins on concanavalin A and wheat germ agglutinin columns was in the range 0.5–1 μg; (3) N-linked oligosaccharides were isolated from co…
Phosphororganische Verbindungen, 110. Gezielte Fluoreszenzmarkierung von Serin-Enzymen
1985
Verbindungen vom Typ R1R2P(O)X [X = F, OC6H4NO2-(4)] sind OH-selektiv und reagieren mit der Serinhydroxygruppe im aktiven Zentrum von Esterasen (α-Chymotrypsin, Trypsin, Butyrylcholinesterase, Acetylcholinesterase und Subtilisin) unter Bildung des entsprechenden inaktiven Phosphorylesters [R1R2P(O)-O-Ser-Esterase]. Mit R1 = 5-(Dimethylamino)naphthyl bzw. 5-Methoxynaphthyl und R2 = Alkyl, Aryl, O-Alkyl erhalt man die chemoselektiven, fluoreszierenden Reagenzien 1–7, welche die oben genannten Esterasen spezifisch hemmen. Es wurde a) die Abhangigkeit der Inhibierung von der Konzentration der Inhibitoren bestimmt und b) durch Gelelektrophorese des inhibierten Enzyms gezeigt, das der fluoreszier…
Functional Characterization of a Guanylyl Cyclase-activating Protein from Vertebrate Rods
1996
The membrane-bound guanylyl cyclase in vertebrate photoreceptor cells is one of the key enzymes in visual transduction. It is highly sensitive to the free calcium concentration ([Ca2+]). The activation process is cooperative and mediated by a novel calcium-binding protein named GCAP (guanylyl cyclase-activating protein). We isolated GCAP from bovine rod outer segments, determined amino acid sequences of proteolytically obtained peptides, and cloned its gene. The Ca2+-bound form of native GCAP has an apparent molecular mass of 20.5 kDa and the Ca2+-free form of 25 kDa as determined by SDS-polyacrylamide gel electrophoresis. Recombinant GCAP was functionally expressed in Escherichia coli. Act…
Partial purification and initial characterization of phytochrome from the mossAtrichum undulatum P. Beauv. grown in the light.
1988
The extraction and partial purification of phytochrome from light-grownAtrichum undulatum P. Beauv., a chlorophyllous moss, is described. Polyethyleneimine and salt fractionation followed by hydroxyapatite and Affi-gel-blue chromatography were used to separate phytochrome from chlorophyll, and to purify the pigment. All steps were performed in the presence of Triton X-100 which improved the yield by a factor of about three. The protein has a molecular weight some-what larger than that ofAvena phytochrome (124 kDa), as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis. It cross-reacts with a monoclonal antibody against phytochrome from etiolated …
C8 Reference Typing Report and Nomenclature Recommendation
1990
Using two different typing techniques (i.e. polyacrylamide gel isoelectric focusing (PAGIF) with Western blot and SDS-polyacrylamide gel electrophoresis of precipitated C8 under nonreducing conditions with Western blot), the following observations were made during the reference typing for C81 (C8A). The Japanese variant A1J is probably identical with A1Cauc, whereas B1J is definitely different from B1Cauc and could therefore provisionally be named HB3'. Variant 'A2' from Japan is focused in an intermediate position, but different from M1 and could be named 'M2'. Both variants possess normal A subunits. B2 from Japan is clearly different from B1Cauc and should retain its designation. In PAGI…
Influence ofKi-ras-driven oncogenic transformation on the protein network of murine fibroblasts
2007
Ki-ras gene mutations that specifically occur in codons 12, 13 and 61 are involved in the carcinogenesis of acute myeloid leukemia, melanoma and different carcinomas. In order to define potential mutation-specific therapeutic targets, stable transfectants of NIH3T3 cells carrying different Ki-ras4B gene mutations were generated. Wild type Ki-ras transformants, mock transfectants and parental cells served as controls. These in vitro model systems were systematically analyzed for their protein expression pattern using two-dimensional gel electrophoresis followed by mass spectrometry and/or protein sequencing. Using this approach, a number of target molecules that are differentially but coordi…
A comparative assay of epidemiological markers for Acinetobacter strains isolated in a hospital.
1989
Summary A comparative assay for epidemiological evaluation of three different Acinetobacter typing procedures, i.e. biotyping, phagetyping, and the analysis of the bacterial envelope protein profiles, was carried out using sixty-four multiresistant Acinetobacter strains isolated from clinical specimens. The antibiotic susceptibility of the strains was also considered. After genospecies identification, biotyping allowed the recognition of a relatively large and long-lasting presence, at an Intenive Therapy Unit, of two A. baumannii biotypes. Phage-typing and the analysis of the susceptibility to antibiotics allowed for the differentiation of strains belonging to different genospecies and bio…
Genetic polymorphism of human complement factor I (C3b inactivator) in the Chinese Han population.
1999
The human complement factor I (IF) polymorphism has been analysed by polyacrylamide gel isoelectric focusing electrophoresis of neuraminidase-treated EDTA plasma samples followed by immunoblotting and enzymatic detection. In a population study among 121 random individuals from Chengdu, PR China, three different common phenotypes were observed. The results show that IF is polymorphic in the Chinese population. The allele frequencies were as follows: FI*A = 0.153, FI*B = 0.847. The distribution of observed phenotypes was in accordance with the Hardy-Weinberg equilibrium. In comparison to other Asian population studies, the frequency of the IF*A allele was the highest in the Chinese population…
Human complement C81 (C8 A) polymorphism: detection and segregation of new variants
1993
In addition to the earlier detected C81(A) rare variants A1, A2 (now A3) and B1 (now B2), six new rare variants (C81 A2 new, A4, A5, A6, M1 and B1new) are described within the polymorphism of the eighth component of human complement (alpha-gamma chain subunit). Except for A3, all rare C81 A variants are only detected by isoelectric focusing, and not by SDS polyacrylamide gel electrophoresis (PAGE), in the alpha-gamma subunit. In one individual out of approximately 700 individuals studied, a reversed position of the common allele (B vs A) was observed by SDS PAGE and the isofocusing technique. The segregation of A1, A3 and A4 could be followed in putative father/child combinations.