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- Baniulis, Danas, et al.
(författare)
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Monoclonal antibody CL5 recognizes the amino terminal domain of human phagocyte flavocytochrome b558 large subunit, gp91phox
- 2005
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 74:4, s. 337-347
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Tidskriftsartikel (refereegranskat)abstract
- Human phagocyte flavocytochrome b558 (Cytb) is a heterodimeric integral membrane protein that serves as the electron transferase of the β-nicotinamide adenine dinucleotidephosphate, reduced (NADPH)-oxidase, an enzyme complex important in the host defense function of phagocytic cells. In this study, we report the characterization of monoclonal antibody (mAb) CL5 that is specific for the large subunit, gp91phox, of the oxidase protein. This antibody recognizes gp91phox by immunoblot analysis of membrane extracts and samples of the immunopurified gp91phox/p22 phox heterodimer, prepared on anti-p22phox affinity matrices. Phage display analysis confirmed this specificity, indicating that the CL5 epitope contains the region 135-DPYSVALSELGDR of gp91phox. The antibody was used to probe for the presence of gp91phox in membrane preparations from neutrophils of patients with nine genetically distinct forms of X-linked chronic granulomatous disease (CGD). The causative mutations included missense errors as well as nonsense errors that result in premature termination of gp91phox synthesis. Analysis of the CGD samples by immunoblotting indicated that CL5 recognizes only the full-length wild-type and two missense mutations, consistent with the absence of stable short gp91 phox peptide expression in CGD neutrophils. Interestingly, CL5 was also shown to be cross-reactive with cytosolic and membrane-bound gelsolin, identified by purification, mass spectrometry and immunoblot analysis. CL5 probably cross-reacts with the sequence 771-DPLDRAMAEL in the C-terminus of gelsolin. We conclude that mAb CL5 is a useful probe for detection of full length and possibly truncated N-terminal fragments of gp91phox from membranes of Cytb-producing cells. © Blackwell Munksgaard 2005.
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| 2. |
- Baniulis, Danas, et al.
(författare)
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Unusual polyclonal anti-gp91phox peptide antibody interactions with X-linked chronic granulomatous disease-derived human neutrophils are not from compensatory expression of Nox proteins 1, 3, or 4
- 2005
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 74:3, s. 241-249
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Tidskriftsartikel (refereegranskat)abstract
- To obtain topological information about human phagocyte flavocytochrome b558 (Cytb), rabbit anti-peptide antibodies were raised against synthetic peptides mimicking gp91phox regions: 1-9 (MGN), 30-44 (YRV), 150-159 (ESY), 156-166 (ARK), 247-257 (KIS-1, KIS-2). Following affinity purification on immobilized peptide matrices, all antibodies but not prebleed controls recognized purified detergent-solubilized Cytb by enzyme-linked immunosorbent assay (ELISA). Affinity-purified antibodies recognizing KIS, ARK and ESY but not YRV, MGN or prebleed IgG specifically detected gp91phox in immunoblot analysis. Antibodies recognizing MGN, ESY, ARK and KIS but not YRV or the prebleed IgG fraction labeled intact normal neutrophils. Surprisingly, all antibodies, with the exception of YRV and pre-immune IgG controls, bound both normal and Cytb-negative neutrophils from the obligate heterozygous mother of a patient with X-linked chronic granulomatous disease (X-CGD) and all neutrophils from another patient lacking the gp91phox gene. Further immunochemical examination of membrane fractions derived from nine genetically unrelated patients with X-CGD, using an antibody that recognizes other Nox protein family members, suggests that the unusual reactivity observed does not reflect the compensatory expression of gp91phox homologs Nox1, 3 or 4. These results suggest that an unusual surface reactivity exists on neutrophils derived from X-linked chronic granulomatous disease patients that most likely extends to normal neutrophils as well. The study highlights the need for caution in interpreting the binding of rabbit polyclonal antipeptide antibodies to human neutrophils in general and, in the specific case of antibodies directed against Cytb, the need for Cytb-negative controls.
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