scholarly journals Isolation and electrophoretic characterization of the plasma membrane of sea-urchin sperm

1983 ◽  
Vol 59 (1) ◽  
pp. 13-25
Author(s):  
N.L. Cross

A subcellular fraction containing plasma membranes was isolated from flagella of the sperm of Strongylocentrotus purpuratus by differential centrifugation, and analysed by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. Coomassie Blue staining revealed nine major bands and 14 minor species. Five bands of apparent molecular weights approximately 200 X 10(3), 149 X 10(3), 120 X 10(3), 75 X 10(3) and 59 X 10(3) also stained with periodic acid-Schiff's reagent and so are probably glycoproteins. These five components are externally exposed, as determined by lactoperoxidase-catalysed radio-iodination. Isolation of membranes from radio-iodinated sperm results in an enrichment of about tenfold in the specific activity of 125I. Comparison of the electrophoretic patterns of labelled sperm and of the membranes isolated from 125I-labelled sperm suggests that no major labelled proteins are lost during the isolation procedure, and so to this extent the membrane fraction is representative of the entire sperm plasma membrane.

1992 ◽  
Vol 4 (2) ◽  
pp. 249 ◽  
Author(s):  
A Paliwal ◽  
B Malaviya ◽  
VP Kamboj

Oviducts were obtained from monkeys on Days 8, 14, 19 and 25 of the menstrual cycle and changes in the pattern of luminal fluid proteins were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis after periodic acid Schiff's reagent (PAS) and coomassie blue staining of the gels revealed 85 and 95 kDa proteins only up to Day 14 whereas a 130 kDa glycoprotein persisted up to Day 19 and reached a nadir at mid-menstrual cycle (Day 14). The absence of the 130 kDa glycoprotein in the serum and its presence in cytosolic preparations up to Day 19 suggest that it is of oviductal origin. The 130 kDa glycoprotein is of particular interest since it was present in the oviductal fluid during mid cycle, a period when the oviduct participates in gamete transport, fertilization and embryo development. The conclusion drawn from this study is that the protein profile of monkey oviductal fluid changes during the menstrual cycle.


1984 ◽  
Vol 219 (1) ◽  
pp. 301-308 ◽  
Author(s):  
A A Davies ◽  
N M Wigglesworth ◽  
D Allan ◽  
R J Owens ◽  
M J Crumpton

Purified preparations of lymphocyte plasma membrane were extracted exhaustively with Nonidet P-40 in Dulbecco's phosphate-buffered saline medium. The insoluble fraction, as defined by sedimentation at 10(6) g-min, contained about 10% of the membrane protein as well as cholesterol and phospholipid. The lipid/protein ratio, cholesterol/phospholipid ratio and sphingomyelin content were increased in the residue. Density-gradient centrifugation suggested that the lipid and protein form a common entity. As judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the Nonidet P-40-insoluble fractions of the plasma membranes of human B lymphoblastoid cells and pig mesenteric lymph-node lymphocytes possessed similar qualitative polypeptide compositions but differed quantitatively. Both residues comprised major polypeptides of Mr 28 000, 33 000, 45 000 and 68 000, together with a prominent band of Mr 120 000 in the human and of Mr 200 000 in the pig. The polypeptides of Mr 28 000, 33 000, 68 000 and 120 000 were probably located exclusively in the Nonidet P-40-insoluble residue, which also possessed a 4-fold increase in 5′-nucleotidase specific activity. The results indicate that a reproducible fraction of lymphocyte plasma membrane is insoluble in non-ionic detergents and that this fraction possesses a unique polypeptide composition. By analogy with similar studies with erythrocyte ghosts, it appears likely that the polypeptides are located on the plasma membrane's cytoplasmic face.


1982 ◽  
Vol 152 (1) ◽  
pp. 298-305
Author(s):  
P Dehazya ◽  
R S Coles

To study the hemagglutinin of Fusobacterium nucleatum, methods were sought to solubilize and purify this component. When cells of F. nucleatum were ruptured by passage through a French press, the fragments lost virtually all ability to agglutinate human erythrocytes. Extraction of the fragments with 2% Triton X-100 for 30 min at 22 degrees C restored hemagglutinating activity (HA). Hemagglutination by these fragments could be inhibited by arginine, as can hemagglutination by intact bacteria. Treatment of active cell wall fragments with pronase and 2% Triton X-100-EDTA at 37 degrees C or with pronase and 0.1% Triton X-100-EDTA at pH 10.0 allowed recovery of solubilized HA. The former HA was inhibited by arginine (arg+) whereas the latter was not (arg-). Fractionation of the arg+ extract by preparative isoelectric focusing showed that HA was recovered from the gel sections having a pH between 4.5 and 5.5. Hemagglutination by this preparation was still arg+. Chromatography of this hemagglutinin on DEAE-Sephadex increased the specific activity to high levels with a loss of inhibition by arginine. A fraction from the DEAE-Sephadex column containing 10,700 HA units per mg of protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Solubilization at 22 degrees C before electrophoresis revealed three Coomassie blue-staining bands which migrated with apparent molecular weights of about 21,000, 38,000 and 60,000. When the same DEAE fraction was boiled in sodium dodecyl sulfate, electrophoresis revealed only one band with an apparent molecular weight of 21,000.


Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1212-1219 ◽  
Author(s):  
N Kieffer ◽  
B Boizard ◽  
D Didry ◽  
JL Wautier ◽  
AT Nurden

Abstract We report the immunochemical characterization of a new platelet- specific alloantigen detected using an IgG antibody isolated from the serum of a patient with posttransfusion purpura (PTP). In indirect immunoprecipitation experiments, the antibody, termed anti-Leka, predominantly precipitated glycoprotein (GP) IIb from Triton X-100 lysates of normal human platelets. In an immunoblot procedure, which involved the transfer of platelet polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to nitrocellulose membrane, anti-Leka bound exclusively to GP IIb. Under identical conditions, four anti-PlA1 antibodies each reacted with GP IIIa. No binding of anti-Leka IgG occurred to Leka (-) platelets or to their separated polypeptides although GP IIb was normally detected by Coomassie blue staining. After electrophoresis of reduced platelet proteins, the Leka determinant was localized to the IIb alpha chain. Thus, unlike the PlA1 antigen, the Leka determinant was not destroyed by disulfide reduction. Analysis of platelets from a patient with Glanzmann's thrombasthenia revealed little or no binding in the GP IIb position. Anti-Leka permitted the identification of 76,000 and 60,000 dalton fragments of GP IIb retained by the platelet following chymotrypsin treatment. Our results further highlight the immunogenicity of the GP IIb-IIIa complex. They also suggest that antibodies against GP IIb can cause the thrombocytopenia observed in PTP and that anti-PlA1 antibodies do not account exclusively for the pathophysiology of this immune disorder.


1981 ◽  
Vol 195 (2) ◽  
pp. 389-397 ◽  
Author(s):  
D A Wiginton ◽  
M S Coleman ◽  
J J Hutton

Adenosine deaminase was purified 3038-fold to apparent homogeneity from human leukaemic granulocytes by adenosine affinity chromatography. The purified enzyme has a specific activity of 486 mumol/min per mg of protein at 35 degrees C. It exhibits a single band when subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, non-denaturing polyacrylamide-gel electrophoresis and isoelectric focusing. The pI is 4.4. The enzyme is a monomeric protein of molecular weight 44000. Both electrophoretic behaviour and molecular weight differ from those of the low-molecular-weight adenosine deaminase purified from human erythrocytes. Its amino acid composition is reported. Tests with periodic acid-Schiff reagent for associated carbohydrate are negative. Of the large group of physiological compounds tested as potential effectors, none has a significant effect. The enzyme is specific for adenosine and deoxyadenosine, with Km values of 48 microM and 34 microM respectively. There are no significant differences in enzyme function on the two substrates. erythro-9-(2-Hydroxy non-3-yl) adenine is a competitive inhibitor, with Ki 15 nM. Deoxycoformycin inhibits deamination of both adenosine and deoxyadenosine, with an apparent Ki of 60-90 pM. A specific antibody was developed against the purified enzyme, and a sensitive radioimmunoassay for adenosine deaminase protein is described.


1983 ◽  
Vol 31 (6) ◽  
pp. 709-716 ◽  
Author(s):  
M R Green

Proteins in colostrum and skimmed milk from humans and mice were separated by electrophoresis on polyacrylamide gels and stained with Coomassie blue (CB), Ethyl-Stains-all (ESA), and periodic acid-Schiff (PAS) to investigate changes that may occur in milks throughout lactation. In mouse colostrum but not in mature mouse milk, a PAS-positive protein of apparent molecular weight of 60,000 stained prominently blue with ESA. A protein in human milk with a molecular weight of 68,000 stained similarly but was present throughout lactation. The intensity of blue staining of these minor proteins in milk approached that obtained with casein phosphoproteins. The metachromatic dye ESA stains phosphoproteins and sialic acid-rich glycoproteins blue to blue-green. Removal of phosphorus from the former and sialic acid from the latter results in those proteins staining red with ESA. The intensity of blue staining of the 60,000 and 68,000 Mr proteins was diminished but not lost following treatment with phosphatase. It was eliminated following neuraminidase digestion of the mouse protein and mild acid hydrolysis of the human protein. Coomassie blue staining of the proteins was not affected by these procedures. Following electrophoresis of milk and milk fractions in a non-sodium dodecyl sulfate-containing system, the proteins were identified by their characteristic staining properties with ESA and isolated.


1990 ◽  
Vol 258 (1) ◽  
pp. C179-C184 ◽  
Author(s):  
G. Schmalzing ◽  
P. Eckard ◽  
S. Kroner ◽  
H. Passow

During meiotic maturation, plasma membranes of Xenopus laevis oocytes completely lose the capacity to transport Na and K and to bind ouabain. To explore whether the downregulation might be due to an internalization of the sodium pump molecules, the intracellular binding of ouabain was determined. Selective permeabilization of the plasma membrane of mature oocytes (eggs) by digitonin almost failed to disclose ouabain binding sites. However, when the eggs were additionally treated with 0.02% sodium dodecyl sulfate (SDS) to permeabilize inner membranes, all sodium pumps present before maturation were recovered. Phosphorylation by [gamma-32P]ATP combined with SDS-polyacrylamide gel electrophoresis (PAGE) and autoradiography showed that sodium pumps were greatly reduced in isolated plasma membranes of eggs. According to sucrose gradient fractionation, maturation induced a shift of sodium pumps from the plasma membrane fraction to membranes of lower buoyant density with a protein composition different from that of the plasma membrane. Endocytosed sodium pumps identified on the sucrose gradient from [3H]ouabain bound to the cell surface before maturation could be phosphorylated with inorganic [32P]phosphate. The findings suggest that downregulation of sodium pumps during maturation is brought about by translocation of surface sodium pumps to an intracellular compartment, presumably endosomes. This contrasts the mechanism of downregulation of Na-dependent cotransport systems, the activities of which are reduced as a consequence of a maturation-induced depolarization of the membrane without a removal of the corresponding transporter from the plasma membrane.


1987 ◽  
Vol 33 (10) ◽  
pp. 1886-1887 ◽  
Author(s):  
T Marshall ◽  
K M Williams

Abstract We applied a simple sodium dodecyl sulfate-polyacrylamide gel electrophoresis method to urine. The method, developed for serum protein analysis (Clin Chem 1984;30:475-9), has a high sample throughput and gives excellent resolution with unconcentrated urine. It clearly distinguishes and characterizes proteinuric urine (7.5 microL) by Coomassie Blue staining and gives complex silver-stained patterns with nonproteinuric urine (2 microL). The former is recommended for routine clinical screening, the latter for research purposes.


1981 ◽  
Vol 52 (1) ◽  
pp. 313-325
Author(s):  
C.A. Colaco ◽  
W.H. Evans

In view of our limited knowledge of the biochemical composition of intercellular junctions, a method was developed for the preparation from rats and mice of plasma membranes containing cardiac intercalated disks. When these membranes were extracted with detergents, e.g. N-lauryl sarcosinate or deoxycholate, the detergent-insoluble material contained structures derived mainly from fascia adherentes junctions, but a few gap junctions and maculae adherentes were also present. When the detergent extraction was carried out at an alkaline pH, the maculae adherentes junctions were dissolved. Fractionation of the detergent-insoluble extract on a sucrose gradient yielded a fraction containing fascia adherentes junction of density 1.20-1.26 g/cm3. Gap junctions banded at a lower density, 1.16-1.20 g/cm3. Polyacrylamide gel electrophoresis showed that the major polypeptide bands in the fascia adherentes-enriched fraction were of molecular weights 134000, 108000, 62–64000, 58000, 47000 and 43000. Although fractions with the gap junctions were contaminated by fascia adherentes junctions, the major polypeptides were calculated by subtraction to be of mol. wt 37000, 26000 and 19000. Two glycoproteins corresponding to minor polypeptides visualized by Coomassie Blue staining were present in the fascia adherentes fraction. Comparison of the fascia adherentes-enriched fraction with a Z-disc fraction prepared from rabbit hearts indicated a different morphology and polypeptide composition.


1990 ◽  
Vol 271 (1) ◽  
pp. 171-178 ◽  
Author(s):  
C Enrich ◽  
P Tabona ◽  
W H Evans

1. Polypeptides of liver plasma membrane fractions enriched in three surface domains of hepatocytes, blood-sinusoidal, lateral and bile canalicular, were analysed by isoelectric focusing (IEF) and non-equilibrium pH gel electrophoresis (NEPHGE) across a wide pH range, followed by SDS/PAGE. The overall Coomassie Blue-stained polypeptide patterns in the fractions were different. lateral plasma membrane fractions contained a characteristically higher number of polypeptides focusing at the basic pH range, whereas few basic polypeptides were present in sinusoidal plasma membrane fractions. The glycoproteins in these plasma membrane fractions stained by a lectin overlay technique with radio-iodinated concanavalin A, wheat-germ agglutinin and a slug lectin, were also different. 2. The polypeptides and glycoproteins of ‘early’ and ‘late’ endosome fractions were also compared by two-dimensional electrophoresis. Their composition was shown by Coomassie Blue staining, lectin overlay staining and in membranes metabolically labelled with [35S]methionine to be generally similar. The glycoproteins of sinusoidal plasma membranes and early and late endosomes were generally similar, but major differences in polypeptides of molecular mass 20-50 kDa, pI 7.5-8.5, in plasma membranes and endosomes were demonstrated, with a specific population of basic (pI 8-9) low-molecular-mass polypeptides being present at highest levels in ‘late’ endosomal fractions (shown by Coomassie Blue staining). 3. Analysis of the distribution of three specific membrane glycoproteins identified by using immunoblotting techniques showed that the asialoglycoprotein and the divalent-cation-sensitive mannose 6-phosphate receptors were present in sinusoidal plasma membrane and in early and late endocytic fractions: they were not detected in canalicular plasma membrane fractions. In contrast, 5′-nucleotidase was detected in all fractions examined. The role of the endocytic compartment in regulating trafficking pathways between the plasma membrane domains of the hepatocyte is discussed.


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