scholarly journals Microvilli of the human term placenta Isolation and subfractionation by centrifugation in sucrose density gradients

1981 ◽  
Vol 196 (1) ◽  
pp. 121-132 ◽  
Author(s):  
P Truman ◽  
J S Wakefield ◽  
H C Ford
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Density Gradients ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Human Term Placenta ◽  
Morphology And Morphometry ◽  
Microscopic Morphology

Human placental microvilli were isolated and separated into two fractions by centrifugation in sucrose density gradients. Electron-microscopic morphology and morphometry, the distribution of enzymic activities and the results of sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of proteins were used to assess the purity of the final preparations and to define their properties. The combined evidence strongly suggested that the preparations contained negligible material that was not plasma membrane. The two fractions of microvilli differed in buoyant density, protein composition, enzyme specific activities and microscopic appearance. Some of these differences were explained by the absence of internal structure in the microvilli of the lighter fraction.

Purification of infectious pancreatic necrosis (IPN) virus and comparison of polypeptide composition of different isolates

1978 ◽  
Vol 24 (1) ◽  
pp. 19-27 ◽  
Author(s):  
N. Chang ◽  
R. D. MacDonald ◽  
T. Yamamoto
Keyword(s):  
Gel Electrophoresis ◽  
Pancreatic Necrosis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Sodium Dodecyl ◽  
Particle Diameter ◽  
Virus Infectivity ◽  
Electron Microscopic ◽  
Infectious Pancreatic Necrosis ◽  
Virus Isolates

Infectious pancreatic necrosis (IPN) virus was partially purified by freon extraction of infected CHSE-214 cells and concentrated by polyethylene glycol (PEG) precipitation of virus from the medium. Both methods resulted in virus concentrates that could be further purified by two CsCl gradient centrifugations with little loss of infectivity. A recovery of 80 to 100% of the virus infectivity was obtained and over 100-fold concentration of viral infectivity was achieved by these methods. This purification was used to compare 10 isolates of IPN virus with regard to their physiochemical properties by electron microscopy, buoyant density in CsCl, and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of the purified virions. Electron-microscopic observations showed that the virus isolates were identical in that they were isometric, hexagonal in profile, and had a particle diameter of 71 nm. The buoyant densities of the virus isolates in CsCl were found to be 1.33 g/ml. SDS-gel electrophoresis of the virus isolates revealed the presence of three polypeptides of molecular weight 50, 30, and 27 × 103 daltons designated as VP50, VP30, and VP27, respectively.

scholarly journals Isolation and protein composition of gap junctions from rabbit hearts

1982 ◽  
Vol 205 (1) ◽  
pp. 189-194 ◽  
Author(s):  
C K Manjunath ◽  
G E Goings ◽  
E Page
Keyword(s):  
Gap Junctions ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Polyacrylamide Gel ◽  
Major Protein ◽  
Electron Microscopic ◽  
Gap Junctional

We have modified a method for isolating gap-junctional membrane from mouse hearts [Kensler & Goodenough (1980) J. Cell Biol. 86, 755-764] to isolate gap junctions of comparable purity from rabbit hearts more rapidly, with better yield, and without resort to non-ionic detergents. Purification was monitored by electron microscopy of thin-sectioned membrane pellets and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Gap junctions were obtained as vesicles whose mean surface area approximated that of junctions in intact myocardial cells. About 10-20% of the vesicles were ferritin-impermeable. Approx. 125 micrograms of membrane protein was obtained per 8 g of rabbit heart. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of purified gap junctions showed five major protein bands of mol.wts. 46 000, 44 000, 33 000, 30 000 and 28 500 that co-purified with the junctions. This protein composition was nearly identical with that published for gap junctions of mouse hearts, and differed markedly from the protein composition of gap junctions from non-excitable cells (lens and liver). The constancy of junctional protein composition between hearts of two different species and its non-identity with that from liver and lens suggest that, although gap-junctional structure in mammalian tissues seems to be remarkably similar by electron-microscopic techniques, junctional-channel protein composition actually varies from tissue to tissue and may be adapted to the permeability requirements of the tissue.

Observation of reconstituted Lumbricus terrestris hemoglobin with the STEM

1983 ◽  
Vol 41 ◽  
pp. 594-595
Author(s):  
O. H. Kapp ◽  
M. Ohtsuki ◽  
A. V. Crewe ◽  
S. N. Vinogradov
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Lumbricus Terrestris ◽  
Sodium Borate ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Multiple Copies ◽  
Electron Microscopic Appearance ◽  
Sodium Borate Buffer

The annelid extracellular hemoglobins are giant heme containing respiratory proteins (3-4x106 MW) possessing an extraordinary range of physiological function, Their electron microscopic appearance is that of two superimposed hexagons with approximate dimensions of 300 x 200Å by STEM. These unusual proteins are composed of multiple copies of as many as six distinct polypeptides ranging in size from 13 to 37,000 MW as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Possessing approximately 150 hemes per molecule, they represent an alternate solution to the demand for increased efficiency of oxygen transport imposed by the evolution of multicellular organisms.The hemoglobin of Lumbricus terrestris dissociates at alkaline pH yielding a broad overlapping distribution of molecular weight species ranging in size from 25 to 300K. Exposure to 0.05M sodium borate buffer, pH 9.0, for 24 hours, followed by gel filtration on a column of Sepharose C1-6B equilibrated in the same buffer, gives the elution profile shown in Fig. 1.

scholarly journals C5b-9 dimer: isolation from complement lysed cells and ultrastructural identification with complement-dependent membrane lesions.

1979 ◽  
Vol 149 (2) ◽  
pp. 448-458 ◽  
Author(s):  
G Biesecker ◽  
E R Podack ◽  
C A Halverson ◽  
H J Müller-Eberhard
Keyword(s):  
Molecular Weight ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Membrane Attack Complex ◽  
Sedimentation Coefficient ◽  
Fluid Phase ◽  
Lipid Vesicles ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Phase Complex

The membrane attack complex (MAC) of complement was extracted from the membranes of cells lysed by human complement and its properties were compared with those of the fluid phase complex SC5b-9. Upon sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunochemical analysis, the two isolated complexes had identical subunit compositions, except that the MAC lacked the S-protein. The sedimentation coefficient and molecular weight of the extracted and isolated MAC were, respectively, 33.5 S and 1.7 x 10(6) daltons, compared to 23 S and 1.0 x 10(6) dalton for SC5b-9. Because the molecular weight of the MAC is approximately two times greater than that of C5b-0 (800,000 daltons), the MAC is considered the dimer of C5b-9. Under specified conditions, the 33.5 S dimer could be converted to the 23 S monomer without dissociation of subunits. The MAC had the electron microscopic appearance and dimensions that are characteristic for the complement produced ultrastructural membrane lesions. SC5b-9 had a different ultrastructure that is dissimilar to the morphology of the lesions. The isolated MAC could be reincorporated into phospholipid bilayers and assumed on the surface of the resultant lipid vesicles the orientation and appearance of typical complement lesions.

scholarly journals Structural Protein Requirements in Equine Arteritis Virus Assembly

2004 ◽  
Vol 78 (23) ◽  
pp. 13019-13027 ◽  
Author(s):  
Roeland Wieringa ◽  
Antoine A. F. de Vries ◽  
Jannes van der Meulen ◽  
Gert-Jan Godeke ◽  
Jos J. M. Onderwater ◽  
...  
Keyword(s):  
Virus Assembly ◽  
Rna Virus ◽  
Buoyant Density ◽  
Protein Composition ◽  
Equine Arteritis Virus ◽  
Structural Proteins ◽  
Structural Protein ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Virus Particles

ABSTRACT Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae of the order Nidovirales. EAV particles contain seven structural proteins: the nucleocapsid protein N, the unglycosylated envelope proteins M and E, and the N-glycosylated membrane proteins GP2b (previously named GS), GP3, GP4, and GP5 (previously named GL). Proteins N, M, and GP5 are major virion components, E occurs in virus particles in intermediate amounts, and GP4, GP3, and GP2b are minor structural proteins. The M and GP5 proteins occur in virus particles as disulfide-linked heterodimers while the GP4, GP3, and GP2b proteins are incorporated into virions as a heterotrimeric complex. Here, we studied the effect on virus assembly of inactivating the structural protein genes one by one in the context of a (full-length) EAV cDNA clone. It appeared that the three major structural proteins are essential for particle formation, while the other four virion proteins are dispensable. When one of the GP2b, GP3, or GP4 proteins was missing, the incorporation of the remaining two minor envelope glycoproteins was completely blocked while that of the E protein was greatly reduced. The absence of E entirely prevented the incorporation of the GP2b, GP3, and GP4 proteins into viral particles. EAV particles lacking GP2b, GP3, GP4, and E did not markedly differ from wild-type virions in buoyant density, major structural protein composition, electron microscopic appearance, and genomic RNA content. On the basis of these results, we propose a model for the EAV particle in which the GP2b/GP3/GP4 heterotrimers are positioned, in association with a defined number of E molecules, above the vertices of the putatively icosahedral nucleocapsid.

scholarly journals Expression of Aleutian Mink Disease Parvovirus Capsid Proteins in a Baculovirus Expression System for Potential Diagnostic Use

1994 ◽  
Vol 6 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Wai-Hong Wu ◽  
Marshall E. Bloom ◽  
Bradley D. Berry ◽  
Michael J. McGinley ◽  
Kenneth B. Platt
Keyword(s):  
Microscopic Examination ◽  
Expression System ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Electron Microscopic Examination ◽  
Baculovirus Expression System ◽  
Immunoblot Analysis ◽  
Capsid Proteins ◽  
Electron Microscopic ◽  
Nuclear Polyhedrosis

A 2.3-kb cDNA clone encoding Aleutian mink disease parvovirus (ADV) structural proteins VP1 and VP2 was inserted into the polyhedron gene of Autographa calijbmica nuclear polyhedrosis virus (AcNPV) and expressed by the recombinant virus, AcADV-1, in Spodoptera frugiperda-9 cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western immunoblot analysis (WIA) indicated that synthesis of both VP1 and VP2 was being directed by AcADV-1. Fluorescence microscopic examination of AcADV-1 -infected S. frugiperda-9 cells indicated that the recombinant protein was present within the nucleus of the cells, and electron microscopic examination of these cells revealed the presence of small particles 23–25 nm in diameter. Structures resembling empty ADV capsids could be purified on CsCl density gradients, thus indicating that the ADV proteins were self-assembling. The antigenicity of recombinant VP1 and VP2 was evaluated by WIA. Sera collected from 16 mink prior to infection with ADV did not react with VP1 and VP2. Ten sera collected from mink with counter current immunoelectrophoresis (CIE) titers greater than 4 (log2) reacted with VP1 and VP2 in WIA. Two of 6 sera with CIE titers of 4 and 1 of 14 sera with CIE titers <4 reacted with the recombinant proteins. These results suggest that baculovirus recombinant ADV capsid proteins may be useful as diagnostic antigens.

Plant NAD-Dependent Glutamate Dehydrogenase. Purification, Molecular Properties and Metal Ion Activation of the Enzymes from Lemna minor and Pisum sativum

1980 ◽  
Vol 35 (3-4) ◽  
pp. 213-221 ◽  
Author(s):  
Heinz-Walter Scheid ◽  
Adelheid Ehmke ◽  
Thomas Hartmann
Keyword(s):  
Amino Acid ◽  
Pisum Sativum ◽  
Glutamate Dehydrogenase ◽  
Gel Electrophoresis ◽  
Metal Ion ◽  
Lemna Minor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sedimentation Equilibrium ◽  
Electron Microscopic

Abstract Glutamate dehydrogenase (ʟ-glutamate: NAD+ oxidoreductase (deaminating) EC 1.4.1.2) has been purified to homogeneity from Lemna minor and seeds of Pisum sativum. As established by polyacrylamide gel electrophoresis the Pisum-enzyme constitutes a multiple pattern of seven char­ge isoenzymes whereas the Lemna enzyme shows one single protein band. Molecular weights of 230 000 were calculated for both enzymes by sedimentation equilibrium measurements (Pisum-enzyme) and comparative gel filtration (Lemna-enzyme). Sodium dodecyl sulfate gel electrophoresis and electron microscopic observations revealed that both enzymes are composed of four identical subunits (molecular weight 58 500) arranged in a tetraedric structure. The amino acid compositions of both enzymes are similar to those of various hexameric glutamate dehydrogenases. The N-terminal amino acid of the Pisum-enzyme is alanine. Both enzymes require Ca2+ for maximal catalytic activity. For the Lemna-enzyme the K0.5 values for Ca2+ are 22 µᴍ (NADH-dependent reaction) and 4 µᴍ (NAD+ -dependent reaction), respectively. Ca2+ which to some extent can be replaced by Zn2+ does not affect the enzyme aggregation but seems to govern a reversible equilibrium between catalytically active and inactive enzyme forms.

Changes in total and individual proteins during drying and ruminal fermentation of alfalfa

2005 ◽  
Vol 2005 ◽  
pp. 198-198
Author(s):  
A. A. Sadeghi ◽  
P. Shawrang ◽  
M. Moradi ◽  
A. Nikkhah
Keyword(s):  
Crude Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Plant Proteins ◽  
Ruminal Fermentation ◽  
Protein Nitrogen ◽  
Sds Page ◽  
Total Crude Protein ◽  
Hydrolysis Of

Proteolysis within plant cells occurs during wilting and drying. Changes in plant proteins during those periods usually are monitored by measurement of total crude protein and non protein nitrogen. Alternatively, changes in concentrations of individual proteins can be measured. Plants are composed of an array of different proteins. Electrophoresis can be used to separate these proteins and has been used to study effects of wilting and ensiling on proteins of some forages (Grum et al., 1991). Electrophoresis also has been used in the study of ruminal hydrolysis of oilseed meals proteins (Sadeghi et al., 2004). Most of the experiments designed to use electrophoresis to study protein metabolism in forages and ruminants have been qualitative. The main objective of this study was to determine whether sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometry could be used to monitor quantitatively the changes in alfalfa protein composition during wilting, drying and ruminal exposure.

scholarly journals Isolation of the intercellular glycoproteins of desmosomes.

1981 ◽  
Vol 90 (1) ◽  
pp. 243-248 ◽  
Author(s):  
G Gorbsky ◽  
M S Steinberg
Keyword(s):  
Plasma Membranes ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Insoluble Residue ◽  
Differential Centrifugation ◽  
Electron Microscopic ◽  
Nonionic Detergent ◽  
Cell Layers ◽  
Membrane Attachment

To characterize the desmosome components that mediate intercellular adhesion and cytoskeletal-plasma membrane attachment, we prepared whole desmosomes and isolated desmosomal intercellular regions (desmosomal "cores") from the living cell layers of bovine muzzle epidermis. The tissue was disrupted in a nonionic detergent at low pH, sonicated, and the insoluble residue fractionated by differential centrifugation and metrizamide gradient centrifugation. Transmission electron microscopic analyses reveal that a fraction obtained after differential centrifugation is greatly enriched in whole desmosomes that possess intracellular plaques. Metrizamide gradient centrifugation removes most of the plaque material, leaving the intercellular components and the adjoining plasma membranes. Sodium dodecyl sulfate polyacrylamide gel electrophoresis coupled with methods that reveal carbohydrate-containing moieties on gels demonstrate that certain proteins present in whole desmosomes are glycosylated. These glycoproteins are specifically and greatly enriched in the desmosome cores of which they are the principal protein constituents, and thus may function as the intercellular adhesive of the desmosome.

Electrophoretic and electron microscopic examination of the adductor and diductor muscles of an articulate brachiopod, Terebratalia transversa

1982 ◽  
Vol 60 (4) ◽  
pp. 550-559 ◽  
Author(s):  
William P. Eshleman ◽  
Jerrel L. Wilkens ◽  
Michael J. Cavey
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Electron Microscopic Examination ◽  
Light Chains ◽  
Electron Microscopic ◽  
Electrophoretic Patterns ◽  
Transmission Electron ◽  
Adductor Muscles ◽  
Regulation Of Contraction

The proteins of the striated adductor muscles, smooth adductor muscles, and diductor muscles of the articulate brachiopod Terebratalia transversa have been examined by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Electrophoretic patterns indicate the presence of paramyosin in all of these valve muscles. Tentative identification has also been made of the proteins responsible for actin and for myosin regulation of contraction (troponin–tropomyosin and myosin light chains, respectively). The myofilaments of the striated adductor cells, smooth adductor cells, and diductor cells have been characterized by transmission electron microscopy. The smooth adductor cells and the diductor cells exhibit very thick myofilaments which are fusiform in shape, exceptionally long, and axially banded. Morphological features of these thick myofilaments are consistent with those of paramyosin filaments found in other muscles and myoepithelia. Although the striated adductor cells contain paramyosin, it is not manifest in the thick myofilaments.

Sign in / Sign up

Export Citation Format

Share Document