Divalent 5S fragments obtained from rabbit IgG antibodies by tryptic hydrolysis

The giant grouper, Epinephelus itaira, was shown to synthesize 16 and 6.4S antibodies specific for the dinitrophenyl determinant (DNP). Sera obtained at various intervals between 1 month and 2 yr after initial immunization contained both species of antibody; no temporal synthesis was evident. Equilibrium dialysis studies employing ϵ-dinitrophenyl-amino caproic acid were conducted with purified grouper antibodies specific for DNP. The 16S antibody preparations obtained at 1 and 2 months of immunization showed heterogeneity of hapten binding indicative of two populations of combining sites. One-half of these sites (an average of four sites per 16S molecule) exhibited an average intrinsic association constant (Ko) of ∼106M–1; the Ko of the remaining four-sites was ∼104M–1. Thus, the valence of the grouper 16S antibody molecule appears to be eight although the distribution of the high and low Ko sites is unknown, i.e., are they each on the same or on different molecules? The 16S antibody preparations obtained after more prolonged immunization exhibited increasingly lower Ko values; the so-called low Ko sites were no longer detectable. These findings are in contrast to reports of rabbit IgG antibodies showing an increase in Ko with increased time. The 6.4S antibody preparations obtained from the 1 and 2 month antisera had Ko values of ∼106M–1 and a valence of one. These antibodies would not precipitate with antigen. The 6.4S antibody preparations obtained at later times showed decreasing Ko values comparable to those of the 16S antibodies from the same bleedings. Studies on the thermodynamic parameters of the hapten-antibody interaction showed the grouper 16 and 6.4S antibodies to be similar to each other. These data also showed that the enthalpy and entropy changes of grouper antibody-hapten reactions resemble those reported for rabbit IgG antibodies to this hapten. It is thus suggested that, although considerable evolution of immunoglobulin classes has occurred between fish and rabbits, the antibody combining site may have remained relatively unchanged during a large part of evolutionary time.

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Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652002000500001 ◽

2002 ◽

Vol 44 (5) ◽

pp. 239-244 ◽

Cited By ~ 3

Author(s):

Semíramis GUIMARÃES ◽

Maria Inês T. Leme SOGAYAR ◽

Marcello FRANCO

Keyword(s):

Reference Strain ◽

Asymptomatic Patient ◽

Electrophoretic Pattern ◽

Giardia Duodenalis ◽

Igg Antibodies ◽

Immunoblotting Analysis ◽

Rabbit Igg ◽

Sds Page ◽

Axenic Strains ◽

Soluble Fractions

In the present study, we have analyzed by sodium docecyl sulphate - polyacrilamide gel electrophoresis (SDS-PAGE), immunoblotting and Concanavalin A blotting (Con A blotting) proteins of membrane fractions and soluble fractions obtained from Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic (BTU-11) and an asymptomatic patient (BTU-10), as compared to the reference strain Portland 1. Both Brazilian strains showed a complex and homogeneous electrophoretic pattern of proteins, but some differences could be observed. Several glycoproteins were detected, particularly the proteins of 81, 72, 59 kDa and the protein of 62 kDa in the membrane proteins and cytosol, respectively. Many antigenic components were revealed by anti-Giardia rabbit IgG antibodies in the immunoblotting analysis. Among these components, the membrane protein of 32 kDa and the cytosol protein of 30 kDa could be related to giardin, as previously demonstrated.

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A Competitive Inhibition Enzyme Immunoassay for Detection and Quantification of Organophosphorus Compounds

Zeitschrift für Naturforschung C ◽

10.1515/znc-1988-3-403 ◽

1988 ◽

Vol 43 (3-4) ◽

pp. 167-172 ◽

Cited By ~ 11

Author(s):

Peter Schmidt ◽

Reiner Kühlmann ◽

Uli Lösch

Keyword(s):

Enzyme Immunoassay ◽

Cholinesterase Activity ◽

Competitive Inhibition ◽

Organophosphorus Compounds ◽

Good Alternative ◽

Specific Method ◽

Igg Antibodies ◽

Rabbit Igg ◽

Model Substance ◽

Detection And Quantification

A sensitive and specific method for detection and quantification of methyl phosphonic acid, paminophenyl 1,2,2,-trimethyl-propyl diester (MATP) as a model substance for organophosphorus compounds is described. Different procedures for coupling the haptenic group for immunization, purification and immobilization allowed the detection of hapten-specific antibodies. The competitive inhibition enzyme immunoassay (CIEIA), using purified chicken and rabbit IgG-antibodies, was able to detect MATP-concentrations as low as 10-10 mol/1. Based upon our results, we postulate that the CIEIA represents a good alternative to the customary diagnosis of organophosphate intoxications, measuring blood Cholinesterase activity.

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Rabbit IgG Antibodies against Cord Red Blood Cell Membranes Bind to Complement Receptor 1 (CD35)

Acta Haematologica ◽

10.1159/000040886 ◽

1998 ◽

Vol 100 (3) ◽

pp. 123-129

Author(s):

Anna Lisa Giuliani ◽

Roberto Pora ◽

Marina Verenini ◽

Lorenza Unis ◽

Giuseppe Graldi ◽

...

Keyword(s):

Blood Cell ◽

Red Blood Cell ◽

Cell Membranes ◽

Complement Receptor ◽

Igg Antibodies ◽

Rabbit Igg ◽

Complement Receptor 1 ◽

Red Blood Cell Membranes

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Upconverting phosphor technology-based lateral flow assay for the rapid and sensitive detection of anti-Trichinella spiralis IgG antibodies in pig serum

Parasites & Vectors ◽

10.1186/s13071-021-04949-2 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Jian Li ◽

Jing Ding ◽

Xiao-Lei Liu ◽

Bin Tang ◽

Xue Bai ◽

...

Keyword(s):

Trichinella Spiralis ◽

Point Of Care ◽

Cross Reactivity ◽

Lateral Flow ◽

Sensitive Detection ◽

Parasitic Infections ◽

Igg Antibodies ◽

Point Of Care Test ◽

Rabbit Igg ◽

Pig Serum

Abstract Background Trichinella spiralis is a zoonotic food-borne parasite. A disease caused by infection with T. spiralis is called trichinellosis in humans. It is important to investigate the epidemic situation and the surveillance of herds and then prevent infection in humans. Therefore, this study is to develop a rapid and sensitive diagnostic method for on-site test in domestic and wild animals. Methods Upconverting phosphor nanoparticles (UCNPs), an excellent optical label, were conjugated with the excretory-secretory (ES) antigens from T. spiralis muscle larvae (ML) or goat anti-rabbit IgG, and a lateral flow (LF) assay based on these probes (UCNPs-ES/goat anti-rabbit IgG) was developed for the rapid and sensitive detection of anti-T. spiralis IgG antibodies in pig serum. The assay is named the UPT-LF-ES assay. In addition, the probes were characterized, and the assay was optimized. A cut-off threshold of the assay was also identified by using 169 known negative pig samples. Performance of the assay to T. spiralis with different infective numbers, cross-reactivity with other parasitic infections, the single-blinded experiment, and coincidence were evaluated with the assay. Results The UPT-LF-ES assay was successfully constructed and optimized based on the probes of UCNPs-ES/goat anti-rabbit IgG. In the pigs infected with 100, 1000, and 10,000 ML, positive results were first presented at 35 days post-infection (dpi), 30 dpi, and 25 dpi, respectively. The assay had no cross-reaction with other parasitic infections. A single-blinded experiment indicated that the sensitivity and specificity of the UPT-LF-ES assay were 100% and 100%, respectively, the area under the receiver operating characteristic (ROC) curve was 1.000. In addition, the value detected by the UPT-LF-ES assay was significantly different between positive and negative samples. Moreover, compared with the “gold standard” magnetic stirrer method, the coincidence rate of the UPT-LF-ES assay was 87.27%, and the kappa (K) coefficient was 0.7454, showing a substantial agreement. Conclusions The UPT-LF-ES assay is a useful point-of-care test (POCT) with T. spiralis in the detection of pig, which contributes to preventing human trichinellosis. Graphical Abstract

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Double immunocytochemical staining in the study of antibody-producing cells in vivo. Detection of specific antibody-producing cells in the spleen and simultaneous determination whether or not they produce immunoglobulin G antibodies.

Journal of Histochemistry & Cytochemistry ◽

10.1177/32.7.6376616 ◽

1984 ◽

Vol 32 (7) ◽

pp. 677-680 ◽

Cited By ~ 15

Author(s):

N Van Rooijen ◽

N Kors ◽

R Van Nieuwmegen

Keyword(s):

Alkaline Phosphatase ◽

Immunocytochemical Staining ◽

Igg Antibodies ◽

Specific Antibodies ◽

In Vivo Detection ◽

Rabbit Igg ◽

Present Technique ◽

Antibody Class ◽

Ig G

Rabbits were primed intravenously with human serum albumin (HSA) and boosted with the same antigen 2 months later. Cells producing specific antibodies against HSA could be detected in vivo and it could be determined whether or not they belonged to the immunoglobulin (Ig) G class using a combined peroxidase (HRP) and alkaline phosphatase (AP) immunocytochemical technique. HRP-HSA conjugate was used for detection of anti-HSA-producing cells and AP-sheep anti-rabbit IgG (SRIgG) was used to determine the IgG class of the antibodies produced by these cells in the same spleen section. After performing both HRP and AP cytochemistry, cells with a red-stained cytoplasm represent anti-HSA-producing cells not stained for their antibody class and cells with a blue-stained cytoplasm represent cells producing IgG antibodies not directed against HSA. Cells with a double-stained cytoplasm represent cells producing anti-HSA antibodies belonging to the IgG class. We also attempted to determine whether or not part of the anti-HSA-producing cells belonged to the IgM class using AP-sheep anti-rabbit IgM (SRIgM). In this case no double-stained cells were detected, indicating that the affinity of intracellular IgM-anti-HSA antibodies is too low to allow detection using the present technique.

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