scholarly journals Location of an epitopic site on epiglycanin by molecular immunoelectron microscopy

1985 ◽  
Vol 227 (1) ◽  
pp. 231-237 ◽  
Author(s):  
J K Wold ◽  
H S Slayter ◽  
J F Codington ◽  
R W Jeanloz
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Immunoelectron Microscopy ◽  
Gel Filtration ◽  
Strong Tendency ◽  
Gel Filtration Chromatography ◽  
Shadow Casting ◽  
Probable Presence ◽  
Antigen Antibody

Antibodies of the IgM type present in rabbit anti-epiglycanin antiserum were purified by (NH4)2SO4 precipitation and by ion-exchange, affinity and gel-filtration chromatography. After papain treatment of this fraction, followed by gel filtration, the fraction with highest apparent Mr was incubated with epiglycanin, and the antigen-antibody complexes separated by gel filtration. These were examined by electron microscopy, using rotational shadow casting, and the photographs of the complexes were mapped for the locations of the antibody molecules on the extended epiglycanin molecules. Distribution of the frequency of attachment of immunoglobulin showed a strong tendency toward binding at one end of epiglycanin, suggesting the probable presence of only one epitope, probably a glycopeptide structure containing a beta-D-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-D-galactose chain.

Structure of β-casein

1979 ◽  
Vol 46 (2) ◽  
pp. 281-282 ◽  
Author(s):  
Shunrokuro Arima ◽  
Ryoya Niki ◽  
Kenji Takase
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Analytical Ultracentrifugation ◽  
Hydrophobic Interactions ◽  
Gel Filtration ◽  
Random Coil ◽  
Free Energies ◽  
Gel Filtration Chromatography ◽  
Increasing Temperature

SUMMARYThe temperature and concentration dependent association of β-casein was studied by means of viscometry, gel filtration chromatography, electron microscopy, analytical ultracentrifugation and UV difference spectrophotometry. Degrees of polymerization of 12, 22 and 49 and free energies of association of –21, –23 and – 25 kJ/mole monomer were found at temperatures of 10, 15 and 20 °C respectively in 0·2 M Na phosphate buffer pH 6·7.Monomeric β-casein was not a completely random coil but became more compact with increasing temperature, due to hydrophobic interactions.

scholarly journals 554. Efficient Scalable Purification of rAAV1 Using Ion-Exchange and Gel-Filtration Chromatography To Avoid Ultracentrifugation Procedure

2015 ◽  
Vol 23 ◽  
pp. S222
Author(s):  
Taro Tomono ◽  
Yukihiko Hirai ◽  
Hironori Okada ◽  
Tomoko Chiyo ◽  
Takashi Shimada ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Gel Filtration ◽  
Gel Filtration Chromatography

scholarly journals PROPERDIN FACTOR D

1974 ◽  
Vol 140 (2) ◽  
pp. 426-436 ◽  
Author(s):  
Douglas T. Fearon ◽  
K. Frank Austen ◽  
Shaun Ruddy
Keyword(s):  
Ion Exchange ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Direct Interaction ◽  
Electrophoretic Analysis ◽  
Radial Immunodiffusion ◽  
Gel Filtration Chromatography

The protein in the properdin pathway responsible for conversion of precursor factor D to D has been isolated and found to be identical with properdin. Sequential ion exchange and gel filtration chromatography demonstrated identity between properdin protein, measured by radial immunodiffusion, and the capacity to activate D to D, assessed by formation of the intermediate, EAC43B(D). Properdin, purified in this manner, was homogeneous on acid polyacrylamide disc gel electrophoretic analysis, with the band of protein corresponding to the position of eluates in the replicate gel capable of activating highly purified D. Demonstration of the homogeneity of purified D by alkaline disc gel electrophoresis, coupled with the linear stoichiometric hemolytic titrations of each factor, indicates that direct interaction between properdin and D generates D. Thus, activation of D by properdin represents a mechanism in the properdin pathway by which D becomes available for formation of the C3b-dependent C3 convertase.

Chromatographic and immunochemical studies on postsecretory processing of gastrin in the pig

1986 ◽  
Vol 251 (3) ◽  
pp. G300-G307
Author(s):  
D. M. Power ◽  
N. Bunnett ◽  
R. Dimaline
Keyword(s):  
Ion Exchange ◽  
Gel Filtration ◽  
Gastroepiploic Artery ◽  
Antral Mucosa ◽  
Gel Filtration Chromatography ◽  
Venous Outflow ◽  
Luminal Side ◽  
Venous Plasma

Immunoreactive forms of gastrin in antral mucosal extracts and in gastric venous plasma of the pig were compared using ion-exchange and gel-filtration chromatography and radioimmunoassay using three region-specific antiserums. In antral mucosal extracts, gastrin heptadecapeptide (G-17) accounted for over 90% of the total C-terminal immunoreactivity, but in gastric venous plasma it accounted for only 47% of total C-terminal immunoreactivity. The remaining C-terminal immunoreactivity was accounted for by shorter C-terminal forms. Unsulfated and sulfated G-17 contributed 44.1 and 49.2%, respectively, of C-terminal immunoreactivity in antral mucosa. In contrast, they contributed 14 and 30%, respectively, to total C-terminal immunoreactivity in gastric venous plasma. Incubation of antral extracts with plasma in vitro resulted in a slow loss of intact G-17 (32.3% in 60 min) that could not account for the production of C-terminal fragments in vivo. Moreover, when antral extracts were infused into the gastroepiploic artery, over 90% of the gastrin present in the antral venous outflow corresponded to G-17. These observations suggest that it is unlikely that enzymes involved in the generation of the C-terminal forms are located either in blood or on the luminal side of the endothelial membrane. It is proposed, then, that antral gastrin is converted into shorter C-terminal fragments at or before the time it enters the circulation and that the major storage forms of gastrin in tissue account for less than 50% of the material in the gastric venous outflow.

scholarly journals Sulphation heterogeneity in the trisaccharide (GalNAcSβ1,4GlcAβ1,3GalNAcS) isolated from the non-reducing terminal of human aggrecan chondroitin sulphate

1999 ◽  
Vol 342 (1) ◽  
pp. 223-229 ◽  
Author(s):  
Leigh A. WEST ◽  
Peter ROUGHLEY ◽  
Fred R. T. NELSON ◽  
Anna H. K. PLAAS
Keyword(s):  
Ion Exchange ◽  
Direct Effect ◽  
Chondroitin Sulphate ◽  
Gel Filtration ◽  
Gel Filtration Chromatography ◽  
Chondroitinase Abc ◽  
Human Knee ◽  
Ion Exchange Hplc

We report here the isolation and sulphation isomer analyses of trisaccharides GalNAcS(β1,4)GlcA(β1,3)GalNAcS (in which S indicates sulphate) derived from the non-reducing termini of aggrecan chondroitin sulphate. Rat chondrosarcoma and human aggrecans were digested for 1 h at 37 °C with 30 μ-units of endo-chondroitinase ABC per μg of chondroitin sulphate, and trisaccharides were isolated from the digests by ToyoPearl HW40S gel-filtration chromatography. Four trisaccharide species were identified; their sulphation isomer compositions, as determined by digestion with chondroitinase ACII and fluorescence-based ion-exchange HPLC, were GalNAc4Sβ1,4GlcAβ1,3GalNAc4S, GalNAc4Sβ1,4GlcAβ1,3GalNAc6S, GalNAc4,6Sβ1,4GlcAβ1,3GalNAc4S and GalNAc4,6Sβ1,4GlcAβ1,3GalNAc6S. The abundances of such sequences in chondroitin sulphate on aggrecan from normal (foetal to 72 years of age) and from osteoarthritic human knee cartilages were also established. The results showed that non-reducing terminal GalNAc4S or GalNAc4,6S can be linked to either a 4-sulphated or a 6-sulphated disaccharide, suggesting that the sulphation of the last disaccharide might not have a direct effect on the specificity of chondroitin sulphate terminal GalNAc sulphotransferases. Furthermore, for each aggrecan preparation examined, the 4S-to-6S ratio of all chain interior disaccharides was equivalent to that in the last repeating disaccharides at the non-reducing terminus, suggesting that neither chondroitin 4-sulphotransferase nor chondroitin 6-sulphotransferase shows preferential activity near the chain terminus.

scholarly journals Purification and heterogeneity of inorganic pyrophosphatase of pig scapula cartilage

1975 ◽  
Vol 147 (1) ◽  
pp. 103-109 ◽  
Author(s):  
R Felix ◽  
H Fleisch
Keyword(s):  
Enzyme Activity ◽  
Ion Exchange ◽  
High Purity ◽  
Cetylpyridinium Chloride ◽  
Gel Filtration ◽  
Inorganic Pyrophosphatase ◽  
Gel Filtration Chromatography ◽  
Enzyme Preparations ◽  
Specific Activities

Inorganic pyrophosphatase (pyrophosphate phosphohydrolase; EC 3.6.1.1) was purified from pig scapula cartilage by fractionation with N-cetylpyridinium chloride and (NH4)2SO4, followed by ion-exchange and gel-filtration chromatography. Enzyme preparations of high purity were obtained, with specific activities (100-400 units/mg) higher than those previously described for mammalian pyrophosphatases. The enzyme activity could be separated into several subfractions on ion-exchange columns.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

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