A biochemical and ultrastructural study of RNA in yolk platelets of Xenopus gastrulae

Development ◽  
1971 ◽  
Vol 26 (2) ◽  
pp. 181-193
Author(s):  
Robert O. Kelley ◽  
George S. Nakai ◽  
Marlene E. Guganig
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Ultrastructural Study ◽  
Gel Electrophoresis ◽  
Superficial Layer ◽  
Polyvinyl Pyrrolidone ◽  
Low Molecular Weight ◽  
Main Body ◽  
Body Components ◽  
Yolk Platelet

Yolk platelets from Xenopus gastrulae were isolated in a sucrose-polyvinyl pyrrolidone medium, washed, centrifuged four times, and portions of each pellet were prepared for electron microscopy. Electron microscopy revealed isolated platelets to be free of cytoplasmic contamination with progressive disruption of the superficial layer after each washing. Each washing and the final pellet were extracted with phenol and precipitated with ethanol. Orcinol analysis indicated that 50–60 µg of RNA were present in yolk platelets isolated from 1000 gastrulae. Autoradiography of yolk platelets from cells incubated in [5-3H]uridine revealed label in superficial and main body components after treatment with DNase but not after incubation in RNase. Acrylamide-gel electrophoresis suggests that yolk platelet RNA is of both high and low molecular weight.

The utilization of yolk platelets by tissues of Xenopus embryos studied by a safranin staining method

Development ◽  
1965 ◽  
Vol 14 (2) ◽  
pp. 191-212
Author(s):  
G. G. Selman ◽  
G. J. Pawsey
Keyword(s):  
Electron Microscopy ◽  
Amino Acid ◽  
Chemical Analysis ◽  
Amino Acid Composition ◽  
Rana Pipiens ◽  
Staining Method ◽  
Peripheral Zone ◽  
Main Body ◽  
Yolk Platelet ◽  
Similar Amino Acid

The amphibian yolk platelet is a particular kind of food-reserve granule which may be easily recognized by microscopy and which is abundant in the cytoplasm of amphibian eggs and embryos. Wallace & Karasaki (1963) developed a method by which intact yolk platelets were isolated from eggs of Rana pipiens and were shown by electron microscopy to be practically free from other materials. Chemical analysis of such yolk platelets by Wallace (1963a, b) showed that the crystalline main body is made up of two components, a phosphoprotein of similar amino-acid composition to avian phosvitin and a lipoprotein similar to avian α-lipovitellin, the molecular proportions being 2 to 1 respectively. Surrounding this crystalline main body of the yolk platelet there is a granular peripheral zone which has been reported to contain both protein resembling histone (Horn, 1962) and polysaccharide (Ohno, Karasaki & Takata, 1964).

Normal Mature Human Enamel Protein

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 986-987 ◽  
Author(s):  
A. Belcourt
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Electrophoresis ◽  
Protein Concentration ◽  
Polyacrylamide Gel Electrophoresis ◽  
Organic Matrix ◽  
Low Molecular Weight ◽  
Human Enamel ◽  
Weak Density ◽  
Enamel Protein

Pure enamel was prepared using an original microdissection technic. Protein concentration was 375 μg per gram of enamel. Polyacrylamide gel electrophoresis showed a single fast-migrating zone containing a thin double band. Ultracentrifugation studies suggested that the proteins were of low molecular weight or of weak density. Absorption spectra showed a strong absorbance at 260nm. Amino acid analyses yielded a composition of 25% Gly, 13.5% Glu, 11% Ser, 11% Pro, 2% Cys and 2% Hyp. A glucidic content of 15% was estimated and glucose, galactose, mannose and fucose were identified. The organic matrix of enamel seemed to be constituted of two major glycoproteins probably fibrous but different from keratin.

scholarly journals Serological grouping ofTreponema hyodysenteriae

1990 ◽  
Vol 105 (1) ◽  
pp. 79-85 ◽  
Author(s):  
D. J. Hampson ◽  
J. R. L. Mhoma ◽  
B. G. Combs ◽  
J. I. Lee
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Vaccine Development ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cross Reactivity ◽  
Low Molecular Weight ◽  
Serological Response ◽  
Double Immunodiffusion ◽  
Sds Page ◽  
Treponema Hyodysenteriae

SUMMARYTwo Australian isolates ofTreponema hyodysenteriaewhich did not fit within the current serological grouping system for these bacteria wrere examined by agarose gel double immunodiffusion tests (AGDP). Isolate Vic1 was serologically unique, and we propose that it becomes the type organism for a new sixth serological group ofT. hyodysenteriae(Group F). Isolate Q1 was unusual in that lipopolysaccharide (LPS) extracted from it reacted strongly in AGDP with serum raised against the type organism for serogroup D (A1), and also weakly with serum raised against the type organism for serogroup B (WA1). The nature of this cross-reactivity was examined by using cross-absorbed antisera in AGDP, and by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis.The pattern of serological cross-reactivity between Q1, A1 and WA1 was complex and was not fully defined, but the isolate Q1 apparently shared low molecular weight ‘serogroup’ LPS antigens with A1, and shared higher molecular weight LPS antigens with WA1. On this basis Q1 was designated as belonging to serogroup D, although it was recommended that this be qualified as D (B) to indicate the presence of weak cross-reactivity with serogroup B. Such serological cross-reactivity may have significance in relation to the development of immunity toT. hyodysenteriae. Isolate Q1 may be a potentially useful organism for vaccine development because of its ability to induce a good serological response to LPS of treponemes from both serogroups D and B.

scholarly journals SIMPLE METHOD FOR OPTIMIZATION OF HEPARIN AND ENOXAPARIN DETECTION USING AGAROSE GEL ELECTROPHORESIS

2019 ◽  
pp. 12-15
Author(s):  
Ahmad Abdulrahman Almeman
Keyword(s):  
Molecular Weight ◽  
Toluidine Blue ◽  
Gel Electrophoresis ◽  
Optimization Procedure ◽  
Solvent Mixture ◽  
Acid Mixture ◽  
Low Molecular Weight ◽  
Simple Method ◽  
Electrophoresis Method ◽  
Tools And Techniques

Objective: A simple gel electrophoresis method for low-molecular-weight heparins (LMWH) is required for use in a variety of laboratories to allow further identification and purification. This study aimed to optimize the detection of heparin and enoxaparin (low-molecular-weight heparin by gel electrophoresis. Methods: Several gel electrophoresis conditions were tested to optimize the detection of enoxaparin by using a simple method with a modified Volpi’s approach. Multiple gel thicknesses, voltage settings, and enoxaparin concentrations were tested in the optimization procedure. Enoxaparin was purchased from a local supplier as pre-filled pharmaceutical injections. Highly purified 0.5% and 1.0% agarose gels were prepared and a series of enoxaparin concentrations was added to both gels for comparison and optimization. The 0.2% toluidine blue stain was prepared by the addition of 1 ml in an ethanol-water-acetic acid mixture (50:49:1; v/v/w). The staining process comprised two steps: first, toluidine blue was added for 30 min and destained overnight in the solvent mixture. Subsequently, the following morning, the second step was conducted, in which the gel was restained for 30 min with the same concentration of toluidine blue. We continued to stain the gel until the bands were visible. Results: The gel electrophoresis results showed that clearest and sharpest bands were obtained using 65–75 mAh and 85 V settings. At 95 mAh, the bands were slightly washed out. Conclusion: This study successfully facilitated the detection of enoxaparin, a LMWH, and heparin in the laboratory by using simple tools and techniques available in most laboratories.

scholarly journals Galloylglucoses of low molecular weight as mordant in electron microscopy. I. Procedure, and evidence for mordanting effect.

1976 ◽  
Vol 70 (3) ◽  
pp. 608-621 ◽  
Author(s):  
N Simionescu ◽  
M Simionescu
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Tannic Acid ◽  
Sodium Borohydride ◽  
Low Molecular Weight ◽  
High Contrast ◽  
Experimental Conditions ◽  
Complex Effect ◽  
Tissue Contrast ◽  
Tissue Specimens

Gallotannin, consisting mainly of low molecular weight esters such as penta- and hexagalloylglucoses (commercially available as tannic acid produced from Turkish nutgall), can be used for increasing and diversifying tissue contrast in electron microscopy. When applied on tissue specimens previously fixed by conventional methods (aldehydes and OsO4), the low molecular weight galloylglucoses (LMGG) penetrate satisfactorily the cells and induce general high contrast with fine delineation of extra- and intracellular structures, especially membranes. In some features, additional details of their intimate configuration are revealed. Various experimental conditions tested indicate that the LMGG display a complex effect on fixed tissues: they act primarily as a mordant between osmium-treated structures and lead, and concomitantly stabilize some tissue components against extraction incurred during dehydration and subsequent processing. Experiments with aldehyde blocking reagents (sodium borohydride and glycine) suggested that the LMGG mordanting effect is not dependent on residual aldehydes groups in tissues.

Fractionation of Chromatin Components

1973 ◽  
Vol 51 (5) ◽  
pp. 709-720 ◽  
Author(s):  
John J. Monahan ◽  
Ross H. Hall
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Urea Solution ◽  
Equilibrium Density ◽  
Tissue Culture Cell ◽  
Low Molecular Weight ◽  
Nonhistone Proteins

A general method for isolation and fractionation of chromatin into its four major components, DNA, RNA, histories, and nonhistone proteins, is described. The procedure avoids the use of strongly acidic or alkaline conditions, or the use of ionic detergents or phenol. As few as 14 × 106 cells can be used. The procedure is reasonably rapid and has been used successfully with a number of tissue culture cell lines. The chromatin components are dissociated in a 3 M NaCl – 5 M urea solution containing 2-mercaptoethanol and EDTA. The DNA and high molecular weight RNA are collected by high-speed centrifugation and DNA is separated from the RNA by means of Cs2SO4 equilibrium density centrifugation. The histones, nonhistone proteins, and low molecular weight RNA's are fractionated using DEAE-cellulose column chromatography and polyacrylamide gel electrophoresis. A small amount (< 1%) of protein is present in the DNA and RNA fractions. At least 11 low molecular weight RNA subfractions can be detected by means of polyacrylamide gel electrophoresis.

Effects of Thrombin, Chymotrypsin and Aggregated Gamma-Globulins on the Proteins of the Human Platelet Membrane

1977 ◽  
Vol 37 (03) ◽  
pp. 396-406 ◽  
Author(s):  
B Podolsak
Keyword(s):  
Molecular Weight ◽  
Platelet Activation ◽  
Gel Electrophoresis ◽  
Human Platelet ◽  
Polyacrylamide Gel Electrophoresis ◽  
Platelet Membrane ◽  
Low Molecular Weight ◽  
Membrane Glycoproteins ◽  
Membrane Component ◽  
Before And After

SummaryAnalysis of platelet membrane proteins and glycoproteins by SDS Polyacrylamide gel electrophoresis was carried out before and after treatment with thrombin. Extended incubation with thrombin (in the presence of EDTA or adenosine, which inhibit aggregation) produced extensive changes in the bands observed. With incubation times of a few minutes however, the changes were restricted to a glycopeptide, GP IV (approx. 90,000 Daltons) and one or two polypeptides of low molecular weight, in particular polypeptide 16 (approx. 23,000 Daltons). At 0–3° C only polypeptide 16 was still hydrolyzed.Chymotrypsin, which does not activate platelets, attacked glycopeptides I, II, III but no changes were apparent in GP IV and polypeptide 16. When chymotrypsin-treated platelets were further incubated with thrombin, only GP IV and one to two low molecular weight polypeptides, especially polypeptide 16, were affected. As polypeptide 16 appears to be an integral membrane component it is possible that it, either by itself or in combination with GP IV, represents the primary thrombin substrate involved in platelet activation.Aggregated IgG, which also activates platelets, does not modify the membrane glycoproteins but does change the low molecular weight region in particular band 16.

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