scholarly journals An Fc-receptor activity of plasma membranes from guinea-pig peritoneal polymorphonuclear leucocytes

1982 ◽  
Vol 204 (3) ◽  
pp. 625-634 ◽  
Author(s):  
S Tsunawaki ◽  
D Mizuno ◽  
K Kakinuma ◽  
M Kasahara
Keyword(s):  
Guinea Pig ◽  
Immune Complex ◽  
Plasma Membranes ◽  
Binding Activity ◽  
Fc Receptor ◽  
Receptor Activity ◽  
Alpha Amylase ◽  
Polymorphonuclear Leucocytes ◽  
Superoxide Generation ◽  
Intact Cells

Plasma membranes prepared from guinea-pig peritoneal polymorphonuclear leucocytes showed an immune-complex-binding activity that corresponded well with the activity in intact cells. The characteristics of this activity were reversible binding, dependence on the Fc portion of antigen-complexed IgG (immunoglobulin G), competition with aggregated IgG and independence from energy metabolism. These results support the conclusion that the binding activity found in the isolated plasma membranes is an Fc-receptor activity of guinea-pig peritoneal polymorphonuclear leucocytes. The activity showed Kd = 6.7×10(-8) M-IgG and maximum binding of 17 pmol of IgG/mg of membrane protein when measured with an immune complex of alpha-amylase and homologous guinea-pig anti-(alpha-amylase) IgG. Inhibition of the Fc-receptor activity by a series of various salts indicated the contribution of the hydrophobic interaction to the binding. Inhibitory effects of salts or metal-chelating reagents on the Fc-receptor activity were also observed on superoxide generation by these cells induced by the immune complex, suggesting a role of the Fc receptor as the immune-complex-binding site responsible for the initiation of superoxide generation.

The Mechanism by Which Proteolysis Enhances the Ligand-Binding Activity of Guinea Pig Type II Fc Receptor for IgG (Fe RIIB)

1998 ◽  
Vol 123 (5) ◽  
pp. 959-967 ◽  
Author(s):  
Y. Isashi ◽  
T. Yamashita ◽  
S. Nagasawa ◽  
K. Tanaka ◽  
M. Murakami ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Ligand Binding ◽  
Binding Activity ◽  
Fc Receptor ◽  
Type Ii ◽  
Ligand Binding Activity

The fate of the transferrin receptor during maturation of sheep reticulocytes in vitro

1984 ◽  
Vol 62 (11) ◽  
pp. 1246-1254 ◽  
Author(s):  
R. M. Johnstone ◽  
M. Adam ◽  
B. T. Pan
Keyword(s):  
Transferrin Receptor ◽  
Plasma Membranes ◽  
Cultured Cells ◽  
Molecular Size ◽  
Binding Activity ◽  
Intact Cells ◽  
Receptor Phosphorylation ◽  
Receptor Antibody ◽  
Peptide Map

The transferrin receptor of sheep reticulocytes is excised from the cell during in vitro maturation to erythrocytes. The excised receptor may be recovered from the medium by centrifugation at 100 000 × g. Loss of transferrin-binding activity parallels the loss of binding of anti-receptor antibody, as well as RNA content. The released receptor retains the molecular size of the receptor isolated from the plasma membranes (93 000 monomer, 186 000 dimer), has an identical iodotyrosyl peptide map, and is still capable of binding transferrin, as well as an antibody directed against the receptor. The receptor is released in a vesicular form. The major peptides of the vesicles are the receptor and an unidentified peptide of 70 000 whose iodotyrosyl peptide map is distinct from that of the receptor. Although the transferrin receptor has been shown to undergo posttranslational modification (phosphorylation, acylation, and glycosylation) in cultured cells, it has not been established whether any of the transformations are retained in nongrowing cells. In the present communication, it is shown that isolated reticulocyte plasma membranes are capable of receptor phosphorylation, a process previously shown only with intact, cultured cells. The phosphorylating activity is retained in immunoprecipitates of the receptor, but is absent in the vesicles released during maturation. No evidence has been obtained for an effect of either transferrin or an anti-receptor antibody on receptor phosphorylation in intact cells or isolated membranes.

scholarly journals The determination and localization of sialic acid in guinea-pig granulocytes

1980 ◽  
Vol 192 (2) ◽  
pp. 543-550 ◽  
Author(s):  
J W DePierre ◽  
J Lazdins ◽  
M L Karnovsky
Keyword(s):  
Plasma Membrane ◽  
Sialic Acid ◽  
Guinea Pig ◽  
Total Cell ◽  
Polymorphonuclear Leucocytes ◽  
Intact Cells ◽  
Granule Fraction ◽  
Specific Determination ◽  
Chromatographic Procedure

When intact guinea-pig granulocytes (polymorphonuclear leucocytes) disrupted by sonication or with detergent were treated with neuraminidase from Vibrio cholerae, 3.1–3.2 nmol of sialic acid/10(7) cells was released. By using a chromatographic procedure for the specific determination of total cell sialic acid, this releasable portion was found to constitute 70% of the total sialate. All of the neuraminidase-releasable sialic acid of the cells could be removed by enzymic treatment of intact cells with neuraminidase. It thus seemed likely that the neuraminidase-releasable sialic acid is all on the cell surface. To make sure that the result was not due to entry of neuraminidase into the cells, the enzyme was bound covalently to Sepharose 6B, and intact polymorphonuclear leucocytes were treated with the bound enzyme. All of the neuraminidase-releasable sialic acid could still be removed, though more slowly. The cells remained intact and only 1.5–2% of the bound enzyme was released from the Sepharose during incubation. Freed enzyme could have been responsible, at the very most, for release of 18% of the sialic acid. Fractionation studies showed that the nucleus and cytoplasm contain low amounts of sialic acid and that the neuraminidase-releasable sialic acid distributes in a manner similar to the distribution of 5′-nucleotidase, an unambiguous marker for the plasma membrane in these cells. Thus neuraminidase-releasable sialate constitutes a clear marker for the membrane of polymorphonuclear leucocytes. Most of the neuraminidase-insensitive sialate was present in the granule fraction. Removal of sialic acid from intact polymorphonuclear leucocytes did not affect their ecto-AMPase, -ATPase and -p-nitrophenyl phosphatase activities.

Ultrastructural study of cytoskeletal interactions with endosomes in macrophages by quickfreezing and deep-etching method

1990 ◽  
Vol 48 (3) ◽  
pp. 576-577
Author(s):  
Takeshi Baba ◽  
Nobuki Shiozawa ◽  
Masao Hotch ◽  
Shinichi Ohno
Keyword(s):  
Immune Complex ◽  
Ultrastructural Study ◽  
Fc Receptor ◽  
Coated Pits ◽  
Deep Etching ◽  
Receptor Mediated Endocytosis ◽  
Etching Method ◽  
Quick Freezing

Endosomes are vesicular or tubular organelles that play important roles in transports of receptors and receptor―bound ligands during receptor-mediated endocytosis. The mechanisms of endocytic transports from clathrin-coated pits to lysosomes have been studied by many investigators. However, few studies were reported about the interactions between endosomes and cytoskeletons. In this study, Fc-receptor-mediated endocytosis in macrophages are investigated by quick-freezing and deep-etching (QF-DE) method combined with gold-labeled immune complex and “replica scraping method”.

Comparative analysis of the transferrin and lactoferrin binding proteins in the family Neisseriaceae

1989 ◽  
Vol 35 (3) ◽  
pp. 409-415 ◽  
Author(s):  
Anthony B. Schryvers ◽  
B. Craig Lee
Keyword(s):  
Binding Proteins ◽  
Solid Phase ◽  
Bacterial Species ◽  
Binding Activity ◽  
Intact Cells ◽  
Human Transferrin ◽  
Affinity Isolation ◽  
Lactoferrin Receptor ◽  
Solid Phase Binding ◽  
Branhamella Catarrhalis

Intact cells of several bacterial species were tested for their ability to bind human transferrin and lactoferrin by a solid-phase binding assay using horseradish peroxidase conjugated transferrin and lactoferrin. The ability to bind lactoferrin was detected in all isolates of Neisseria and Branhamella catarrhalis but not in isolates of Escherichia coli or Pseudomonas aeruginosa. Transferrin-binding activity was similarly detected in most isolates of Neisseria and Branhamella but not in E. coli or P. aeruginosa. The expression of transferrin- and lactoferrin-binding activity was induced by addition of ethylenediamine di-o-phenylacetic acid and reversed by excess FeCl3, indicating regulation by the level of available iron in the medium. The transferrin receptor was specific for human transferrin and the lactoferrin receptor had a high degree of specificity for human lactoferrin in all species tested. The transferrin- and lactoferrin-binding proteins were identified after affinity isolation using biotinylated human transferrin or lactoferrin and streptavidin–agarose. The lactoferrin-binding protein was identified as a 105-kilodalton protein in all species tested. Affinity isolation with biotinylated transferrin yielded two or more proteins in all species tested. A high molecular mass protein was observed in all isolates, and was of similar size (approximately 98 kilodaltons) in all species of Neisseria but was larger (105 kilodaltons) in B. catarrhalis.Key words: iron, Neisseria, transferrin, lactoferrin, receptor.

Separation of the glycoprotein and ganglioside components of thyrotropin receptor activity in plasma membranes

1977 ◽  
Vol 75 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Maria F. Meldolesi ◽  
Peter H. Fishman ◽  
Salvatore M. Aloj ◽  
Fred D. Ledley ◽  
George Lee ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Receptor Activity ◽  
Thyrotropin Receptor

Identification of an Fc receptor for IgG1 and IgG2 on guinea-pig polymorphonuclear leukocytes

1987 ◽  
Vol 24 (8) ◽  
pp. 831-837 ◽  
Author(s):  
N TOHORU ◽  
T KOICHI ◽  
M JYUNICHI ◽  
S HIDEKI ◽  
S TOSHIRO ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Polymorphonuclear Leukocytes ◽  
Fc Receptor

Ultrastructure of the hepatopancreas of the Pacific white shrimp, Penaeus vannamei (Crustacea: Decapoda)

1988 ◽  
Vol 68 (2) ◽  
pp. 323-337 ◽  
Author(s):  
Thomas Caceci ◽  
Kay F. Neck ◽  
Donal D H. Lewis ◽  
Raymond F. Sis
Keyword(s):  
B Cells ◽  
Plasma Membranes ◽  
Ultrastructural Level ◽  
Pacific White Shrimp ◽  
White Shrimp ◽  
Penaeus Vannamei ◽  
Intact Cells ◽  
The Pacific ◽  
Total Complement ◽  
Electron Microscopes

Fourteen specimens of the hepatopancreas of the Pacific white shrimp, Penaeus vannamei, were prepared for examination with the transmission and scanning electron microscopes and with the light microscope. The histology and ultrastructure of this organ is similar to that seen in other Decapoda. At the ultrastructural level, it was observed that B-cells rupture at approximately the level of gap junctions located on the lateral plasma membranes of the cells, and discharge the contents of their large vacuoles into the intercellular space. This efflux of enzymatic material may be the mechanism by which cells are released from the wall of the tubule at the proximal end: the rupture and collapse of a B-cell may be analagous to the removal of the keystone which supports an arch. Deprived of support, and lacking structural adaptations for cohesion (there are no desmosomes or interdigitations in the epithelium) and with the intercellular material digested, the remaining intact cells collapse into the lumen of the tubule. The lysis of individual cells of all types - R-, F-, and B-cells - may contribute to the tubules’ total complement of digestive enzymes.

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