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Different Isoelectric Points (different + isoelectric_point)
Selected AbstractsAge-dependent variations of cell response to oxidative stress: Proteomic approach to protein expression and phosphorylationELECTROPHORESIS, Issue 14 2005Yuri Miura Dr. Abstract We investigated the protein profiles of variously aged rat astrocytes in response to oxidative stress. After H2O2 -exposure of cells at 100,µM for 30,min, the relative intensity of ten protein spots changed on two-dimensional (2-D) gels compared with control gels after silver staining. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis after in-gel digestion revealed that six of these spots corresponded to three kinds of proteins, each of which was composed of a protein and its modified form with a different isoelectric point (pI). These three proteins were identified as peroxiredoxins (PRDXs) II and III, and calpactin I light chain (p11). H2O2 -exposure increased the intensity of the spot with lower pI and simultaneously decreased that of the spot with higher pI for both PRDXs II and III. In addition, the expression of annexin VII, S -adenosyl- L -homocysteine hydrolase, elongation factor II fragment (EF-II), and adenosine deaminase was increased by H2O2 -exposure in astrocytes from variously aged rats. Using the Pro-Q® Diamond staining, heat shock protein 60,kDa (Hsp 60) and ,-tubulin were observed to be phosphorylated upon H2O2 -exposure. While phosphorylation of ,-tubulin was correlated positively with age, the changes in abundance of ten protein spots as described above were independent of age. These results suggest that aging does not suppress the responses aimed at limiting injury and promoting repair brought about by severe oxidative stress, and might affect cell dynamics including the formation of microtubules. [source] Proteome analysis of cashmereANIMAL SCIENCE JOURNAL, Issue 5 2004Michinari YOKOHAMA ABSTRACT As an analysis of the cashmere proteins by Type IV 2-DE, ten kinds of components, including three components with molecular mass 42,50 kDa whose expression level increased in the winter, were separated. In analyzing nine components of these ten using a mass spectrometer, the three components of molecular mass 70,120 kDa and pI 5.3 were identified as keratin type II microfibrillar (accession no. KRSHL2), keratin 48 k type I microfibrillar component 8c-1 (accession no. KRSHL1) and cytosolic phospholipase A2 (accession no. O77793), respectively. The three components whose expression level increased in the winter, were identified as keratin type I microfibrillar 48 kDa component 8C-1 (accession no. P02534) and keratin type I microfibrillar 47.6 kDa (accession no. P25690) (pI 5.2/42 kDa), keratin type II microfibrillar component 7C (accession no. P15241) and keratin typeII-sheep (accession no. S34165) (pI 5.5/45 kDa), and the keratin type II microfibrillar component 5 (accession no. P25691) (pI 5.8,6.0/45 kDa), respectively. The three components of less than 17 kDa were identified as hair keratin type II intermediate filament (accession no. CAA51836) (pI 5.2) and keratin high-sulfur matrix protein IIIB2 (accession no. P02447) with a different isoelectric point (pI 5.4 and 5.9), respectively. [source] Comparison of the Electrochemical Behavior of the High Molecular Mass Cadmium Proteins in Arabidopsis thaliana and in Vegetable Plants on Using Preparative Native Continuous Polyacrylamide Gel Electrophoresis (PNC-PAGE)ELECTROANALYSIS, Issue 1 2006Bernd Kastenholz Abstract In Arabidopsis cytosol (supernatant) and in supernatants of vegetable plants high molecular mass cadmium proteins with molecular mass 200,kDa were isolated by using preparative native continuous polyacrylamide gel electrophoresis (PNC-PAGE). Because of a different electrochemical behavior of the Cd proteins in Arabidopsis and endive supernatants on using the same PAGE method, it is concluded that the high molecular mass cadmium proteins of Arabidopsis and endive possess different isoelectric points. Consequently, different chemical structures of the Cd proteins with molecular mass 200,kDa are present in Arabidopsis thaliana and in endive. During the electrophoretic separation of vegetable metalloproteins by using the Model 491 Prep Cell from BioRad, electroanalytical processes like electrode reactions may play an important role. [source] Modified expression of cytoplasmic isocitrate dehydrogenase electrophoretic isoforms in seminal plasma of men with sertoli-cell-only syndrome and seminomaMOLECULAR CARCINOGENESIS, Issue 6 2008Mireille Starita-Geribaldi Abstract Two isoforms of human cytoplasmic isocitrate dehydrogenase (IDPc) of close molecular weights and different isoelectric points were identified in human seminal plasma (SP) by two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry (MS). These two isoforms were detected in the normospermic men SP and their expressions were markedly altered in patients with testicular seminoma, the most frequent testicular germ cell cancer (TGCC): increase of the more acidic spot and decrease of the more basic one. Since oligospermia has been considered as a high risk pathological condition for developing a testicular cancer, the two IDPc isoforms were analyzed in SP of a group of secretory azoospermic patients. In this group the two spots displayed similar variations of expression to those observed in testicular seminoma. These results propose IDPc as a promising SP biomarker of testicular seminoma. Whether IDPc alteration in secretory azoospermia is predictive of testicular seminoma remains to be elucidated. © 2007 Wiley-Liss, Inc. [source] Conjugated Polyelectrolytes for Protein Assays and for the Manipulation of the Catalytic Activity of EnzymesCHEMISTRY - AN ASIAN JOURNAL, Issue 8-9 2008Lingling An Abstract A new method has been developed to discriminate between proteins with different isoelectric points by using fluorescent conjugated polyelectrolytes. Charged water-soluble polyfluorenes that contain 2,1,3-benzothiadiazole (BT) units demonstrate intramolecular energy transfer from the fluorene units to the BT sites when oppositely charged proteins are added to the mixture. This results in a shift in emission color from blue to green and a change in the emission intensity of conjugated polyelectrolytes, which makes it possible to assay proteins. The formation of conjugated polyelectrolyte/enzyme complexes by electrostatic interactions can be utilized to manipulate the activity of enzymes by means of local alteration of enzyme charge density. The oppositely charged substrate binds to conjugated polyelectrolyte and reduces the distance between the enzyme and the substrate, leading to an increase in the cleavage reaction rate. The new method has three important features: 1),it offers a convenient "mix-and-detect" continuous approach for protein assays and rapid detection of enzyme activity; 2),the use of water-soluble conjugated polyelectrolytes imparts the sensor with a high sensitivity; 3),this method does not require fluorescent labels on the targets, which should significantly reduce the cost. [source] | |||||||||||||