scholarly journals Dog pancreatic microsomal-membrane polypeptides analysed by two-dimensional gel electrophoresis

1984 ◽  
Vol 217 (1) ◽  
pp. 145-157 ◽  
Author(s):  
M A Kaderbhai ◽  
B M Austen
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Microsomal Membrane ◽  
Translation System ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Microsomal Preparation ◽  
Microsomal Membranes

The two-dimensional polyacrylamide-gel electrophoresis technique of O'Farrell [(1975) J. Biol. Chem 250, 4007-4021] was applied to resolve and analyse the polypeptide composition of dog pancreatic rough microsomal membranes, which were shown to be active in co-translational processing of preprolactin synthesized from pituitary mRNA in a translation system in vitro. About 100 polypeptides are resolved. Treatment of rough microsomal membranes with EDTA and high KCl concentration yielded membranes stripped of their ribosomes with retention of activity for translocation and processing. Stripped microsomal membranes showed a selective concentration of approximately 25 polypeptides in the membranes when analysed by two-dimensional polyacrylamide-gel electrophoresis. The two-dimensional electrophoretic profile was catalogued into polypeptides that are glycoproteins, those that contain free thiol groups disposed at the cytosolic surface of microsomal vesicles and those that are of secretory origin but have been entrapped in the microsomal preparation. Several secretory components, including amylase, procarboxypeptidases, lipase and anionic trypsinogen, were tentatively identified among the microsomal polypeptides. The rough and stripped microsomal membranes from dog pancreas show a characteristic set of seven major acidic polypeptides, which are also identifiable in microsomal-membrane preparations isolated from dog liver and rat liver. One of these polypeptides was identified as protein disulphide-isomerase (EC 5.3.4.1).

scholarly journals Isolation from human chronic-lymphocytic-leukaemia cells of membrane glycoproteins associated with Fc-receptor functions. Physical parameters and production of polyclonal antibodies

1987 ◽  
Vol 245 (1) ◽  
pp. 75-83 ◽  
Author(s):  
G Gorini ◽  
G A Medgyesi ◽  
M Garavini ◽  
K J Dorrington ◽  
J Down
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Gel Electrophoresis ◽  
Lymphocytic Leukaemia ◽  
Polyclonal Antibodies ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fc Receptor ◽  
Polyacrylamide Gel ◽  
Two Dimensional ◽  
Membrane Glycoproteins

Two membrane glycoproteins that bound immune complexes and inhibited Fc-receptor- (FcR-)mediated functions in vitro were purified from human FcR+ chronic-lymphocytic-leukaemia cells. A multi-step purification was developed, consisting essentially in: (i) Tween 40 extraction of crude cell membranes; (ii) solubilization of membrane fragments by Renex-30; (iii) isolation of glycoproteins by affinity chromatography on Lens culinaris haemagglutinin-Sepharose; (iv) papain treatment of the eluted glycoproteins followed by gel-filtration chromatography; (v) purification by polyacrylamide-gel electrophoresis of two molecular species from the protein-size fraction enriched for immune-complex-binding activity. The two electrophoretically isolated components displayed apparent molecular masses of 70 and 45 kDa by SDS/polyacrylamide-gel electrophoresis and restricted charge heterogeneity by two-dimensional analysis. Two-dimensional peptide mapping revealed the presence of many peptides in common between the two proteins and the absence of a number of peptides in the 45 kDa component. These two polypeptides were used as immunogens to produce polyclonal antibodies that cross-reacted with both proteins and specifically inhibited FcR-mediated reactions in vitro. Furthermore, FcR-related components from detergent-extracted lysates of the human K562 and U937 cell lines or human placental membranes were revealed by the putative anti-FcR antibodies adsorbed on Protein A-Sepharose.

A New Method for Proteome Screening with Two-Dimensional Urea-Sds Polyacrylamide Gel Electrophoresis

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Areeba Ahmad ◽  
Riaz Ahmad
Keyword(s):  
Gel Electrophoresis ◽  
Protein Separation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cost Effective ◽  
Polyacrylamide Gel ◽  
Present System ◽  
Liver Protein ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis

AbstractTwo-dimensional gel electrophoresis (2DE) separating proteins on the basis of their pI and molecular mass remain the best available technique for protein separation and characterization to date. But due to several limitations, including streak formation in IEF gels, partial solubility of proteins, expensive running conditions and relatively longer time taken, a simple urea-SDS-2D polyacrylamide gel electrophoresis (US2DE) is described here. The system is reasonably sensitive, cost effective with good reproducibility. The method described in this paper employs a chaotropic agent, urea, in the first dimension and sodium dodecyl sulphate (SDS), like conventional system, in the second dimension with an addition of polyacrylamide to screen the liver proteome of healthy and chemically induced fibrotic rats. The system separates the protein on the basis of chargeto- mass ratio and clearly demonstrates differential expression in the liver protein repertoire of healthy and fibrotic rats. Moreover, the present system, like other 2D electrophoretic procedures revealed at least 22 novel spots in the investigated tissues. The technique may be utilized for comprehensive proteome screening of any biological sample and would provide an overview to narrow down the candidate proteins or biomarkers.

scholarly journals Initiation and processing in vitro of the primary translation products of guinea-pig caseins

1979 ◽  
Vol 184 (2) ◽  
pp. 261-267 ◽  
Author(s):  
R K Craig ◽  
P A J Perera ◽  
A Mellor ◽  
A E Smith
Keyword(s):  
Guinea Pig ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Secretory Proteins ◽  
Post Translational Modifications ◽  
Microsomal Membranes

1. Guinea-pig caseins synthesized in a mRNA-directed wheat-germ cell-free protein-synthesizing system represent the primary translation products, even though they appear to be of lower molecular weight when analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis in parallel with caseins isolated from guinea-pig milk. 2. Identification of the N-terminal dipeptide of the primary translational product of caseins A, B and C and alpha-lactalbumin showed that all shared a common sequence, which was identified as either Met-Arg or Met-Lys. 3. Procedures utilizing methionyl-tRNAfMet or methionyl-tRNAMet in the presence or absence of microsomal membranes during translation provide a rapid method of distinguishing between N-terminal processing of peptides synthesized in vitro and other post-translational modifications (glycosylation, phosphorylation), which also result in a change in mobility of peptides when analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 4. The results demonstrate that guinea-pig caseins, in common with most other secretory proteins, are synthesized with transient N-terminal ‘signal’-peptide extensions, which are cleaved during synthesis in the presence of microsomal membranes.

scholarly journals A novel two-dimensional polyacrylamide-gel pattern, which may be due to allelic genes, of phenylalanine hydroxylase in monkeys

1985 ◽  
Vol 231 (1) ◽  
pp. 197-199 ◽  
Author(s):  
S C Smith ◽  
W McAdam ◽  
R G H Cotton ◽  
J F B Mercer
Keyword(s):  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Phenylalanine Hydroxylase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
The Novel ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Monkey Liver

Two-dimensional gel electrophoresis of immunopurified monkey liver phenylalanine hydroxylase showed a novel form of the enzyme, in 4 out of 24 monkeys, in which each polypeptide spot was split into a doublet with the same charge but slightly different mobility in the sodium dodecyl sulphate/polyacrylamide-gel-electrophoresis (as opposed to the isoelectric-focusing) dimension. Phenylalanine hydroxylase formed by translation of RNA from a liver containing the novel form showed the doublet pattern, suggesting that it is due to differences in mRNA. By analogy with the rat, this mRNA difference could be due to allelic genes.

scholarly journals Protein extraction method of Metroxylon sagu leaf for high resolution two dimensional gel electrophoresis and comparative proteomics

2019 ◽  
Author(s):  
Mehvish Nisar ◽  
Hasnain Hussain
Keyword(s):  
Gel Electrophoresis ◽  
Extraction Method ◽  
Protein Extraction ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Fractionation Method ◽  
Metroxylon Sagu ◽  
Time Required

Abstract Objective This study aimed to determine the best protein extraction method of Metroxylon sagu for the two-dimensional gel electrophoresis and the comparative analysis. Results To perform good proteome research, the most critical step is to establish a method that gives the best quality of extracted total proteins. To develop an optimized protein extraction protocol for two-dimensional polyacrylamide gel electrophoresis (2-DE) analysis of Metroxylon sagu, five protein extraction protocols were compared; polyethene glycol (PEG) fractionation method, SDS/phenol method, TCA/acetone method, combination SDS/phenol and TCA/acetone and imidazole method. The PEG fractionation method was found to give the most reproducible gels with the highest number of spots and highest protein concentration followed by SDS/Phenol method. The lowest number of spots were observed in Imidazole method. The PEG fractionation method provides improved resolution and reproducibility of two-dimensional polyacrylamide gel electrophoresis (2-DE) and reduces the time required to analyze samples. Partitioning rubisco by polyethene glycol (PEG) fractionation provides clearer detection of low-abundance protein. Hence the result from this study propose PEG fractionation as the effective protein extraction method for 2-DE proteomic studies of Metroxylon sagu.

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