Enzyme-labeled type III bacterial Fc receptors

Reis, Kathleen J.; Mering, Gregory O. von; Karis, M.A.; Faulmann, Ervin L.; Lottenberg, Richard; Boyle, M.D.P.

doi:10.1016/0022-1759(88)90228-1

Cited by 24 publications

(8 citation statements)

References 23 publications

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“…Receptors for a number of serum proteins including albumin (16, [30][31][32][33], immunoglobulin (2,5,18,25,35), plasmin (15), fibrinogen (13), 32-microglobulin (12), Clq (34), and kininogen (28) have been recognized on certain gram-positive bacteria. The immunoglobulin-Fc-binding proteins have been studied extensively because of their practical value for immunochemical applications (6,7,10,22,25). Analysis of the type III Fc-binding protein (more frequently designated streptococcal protein G) associated with the majority of human group C and group G streptococcal isolates has revealed a number of interesting properties.…”

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confidence: 99%

Comparison of albumin receptors expressed on bovine and human group G streptococci

1991

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The albumin receptor expressed by bovine group G streptococci was extracted and affinity purified. The protein was characterized for species reactivity, and monospecific antibodies were prepared to the purified receptor. The bovine group G albumin receptor was compared functionally, antigenicaily, and for DNA homology with the albumin-binding protein expressed by human group G streptococci. In agreement with previous reports, the albumin-binding activity of human strains was mediated by a unique domain of the type III immunoglobulin G-Fc-binding molecule, protein G. The albumin receptor expressed by bovine group G strains was found to lack any immunoglobulin G-binding potential but displayed a wider profile of species albumin reactivity than protein G. Both albumin receptors could inhibit the binding of the other to immobilized human serum albumin, and each displayed similar binding properties. Antigenic comparison of the two albumin receptors demonstrated a low level of cross-reactivity; however comparison at the DNA level, using an oligonucleotide probe specific for the albumin-binding region of protein G, demonstrated that the two albumin receptors expressed by human and bovine group G streptococcal strains do not display significant homology.

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confidence: 99%

Comparison of albumin receptors expressed on bovine and human group G streptococci

1991

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“…In 1984 a type III immunoglobulin-binding protein was isolated from a group C streptococcus by Reis et al (13,15), and Bjorck and Kronvall (2) reported isolation of a similar type III binding protein from a group G streptococcus. This type III protein is designated protein G and has been increasingly recognized as a useful tracer for IgG in a variety of direct and indirect immunoassays (14).…”

Section: Discussionmentioning

confidence: 99%

“…Because our previous results had indicated that the correlation between expression of the p antigen and the ability to bind to the Fc region of human IgA was not absolute (4), we also used rabbit anti-p antiserum to detect cell surface and cytoplasmic p antigen. In these experiments, intact or sectioned GBS were reacted with the rabbit antiserum and then with colloidal gold-labeled protein G. Protein G is a type III IgG-binding protein which binds with high affinity to the Fc region of IgG molecules from a variety of species, including rabbit (14).…”

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Colloidal gold immunolabeling of immunoglobulin-binding sites and beta antigen in group B streptococci

1990

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We have characterized the immunoglobulin A (IgA)-Fc-binding properties and beta-antigen expression of several strains of group B streptococci by using ultrastructural immunocytochemistry. Colloidal gold-labeled tracers were used with intact and sectioned bacteria in order to gain information regarding the location and distribution of cell surface and cytoplasmic IgA-Fc-binding molecules and beta antigen. Colloidal gold (5- or 15-nm particles) was conjugated to IgA to characterize IgA-binding properties and to IgG to test for IgG binding. Rabbit anti-beta antiserum was reacted with the bacteria and then with protein G labeled with 15-nm colloidal gold particles. A double-labeling technique was used for simultaneous localization of IgA-Fc- and anti-beta-antibody-binding properties on sectioned bacteria. The data corroborated previous results which indicated that (i) IgA-Fc-binding and IgA-Fc-nonbinding forms of beta antigen can be secreted by strains which do not express beta antigen on the cell surfaces (HG806, VC75); (ii) differences in levels of expression of beta antigen and/or IgA-Fc-binding proteins can be detected among various group B isolates; (iii) group B streptococci do not express human IgG-Fc-binding proteins; and (iv) not all forms of beta antigen are capable of binding human IgA.

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“…Third, perfusion of the particles reduces stagnant mobile phase effects and thereby enhances kinetics of binding to the surface, which also allows for rapid loading of antibody and sample onto the column [24, 251. Fourth, protein G binds antibody at the Fc region which orients antibody with the antigen binding regions away from the surface and towards solution [26]. Proper orientation of the antibody enhances specific activity of the antibody 125, 271.…”

Section: Characterization Of Protein G Columnsmentioning

confidence: 99%

Selective preconcentration for capillary zone electrophoresis using protein G immunoaffinity capillary chromatography

Cole

Kennedy

1995

Electrophoresis

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Capillaries with 150 microns inner diameter were packed with a perfused protein G chromatographic support and used as immunoaffinity preconcentrators for capillary zone electrophoresis. Antibody was loaded onto the protein G support to form an immunoaffinity stationary phase. Injection of samples onto the column caused selective retention and preconcentration of antigen. Injection of appropriate buffers onto the column caused desorption of the antibody and antigen which were then separated by capillary zone electrophoresis. The combination was used on-line and off-line. For on-line combination, a flow-gated interface coupled the two columns and allowed injection of desorbed zones onto the electrophoresis system. Off-line coupling required collection of desorbed fractions and then injection onto the electrophoresis system. Flow rates as high as 100 microL/min were used to load sample onto the affinity column. Desorbing flow rates had to be 1 microL/min or less to prevent excessive dilution during desorption. Using the system, 1 mL insulin samples could be loaded onto the affinity column and desorbed in volumes as small as 1 microL for 1000-fold preconcentration. The use of the preconcentrator with serum samples spiked with insulin was demonstrated.

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Enzyme-labeled type III bacterial Fc receptors

Cited by 24 publications

References 23 publications

Comparison of albumin receptors expressed on bovine and human group G streptococci

Comparison of albumin receptors expressed on bovine and human group G streptococci

Colloidal gold immunolabeling of immunoglobulin-binding sites and beta antigen in group B streptococci

Selective preconcentration for capillary zone electrophoresis using protein G immunoaffinity capillary chromatography

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