Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mannoproteins of approximately 50 kDa from blastoconidia and 60 kDa from hyphae of Candida albicans reacted in Western blots (immunoblots) with either a polyclonal rabbit antiserum (CA-7) or a monoclonal antibody (CA-A) to the C. albicans C3d-binding protein (complement receptor type 2). The glycosylated nature of these proteins was demonstrated by their reactivity with concanavalin A and by selective labeling with the biotin-hydrazide reagent following periodate oxidation. Differences in the oligosaccharides of these proteins were observed in regard to their reactivity with lectin-peroxidase reagents and sensitivity to glycosidases such as N-glycanase or endoglycosidase F (but not endoglycosidase H). The 60-kDa mannoprotein reacted with wheat germ agglutinin, while the 50-kDa mannoprotein did not. Treatment of the 60-kDa mannoprotein with the glycosidases mentioned above resulted in its conversion into a species of 40 to 45 kDa. Enzyme treatment had no obvious effect on the electrophoretic mobility of the 50-kDa species from blastoconidia. Both the 50- and 60-kDa glycoproteins remained immunoreactive after treatment with the glycosidases. Reactivities of the two mannoproteins to neuraminidase also differed. Finally, the 50-kDa (blastoconidia) and the 60-kDa (hyphae) mannoproteins were purified by using ion-exchange chromatography and electroelution. The purified proteins differed in net charge, the 60-kDa species having a more acidic pI. Functional activity of the purified mannoproteins was demonstrated, as each inhibited the rosetting of antibody-sensitized sheep erythrocytes conjugated with iC3b or C3d by hyphae. Thus, an epitope(s) common to both a mycelial and blastoconidial mannoprotein is associated with a structurally different oligosaccharide for each growth form.
 ...
PMID:Analysis of mannoproteins from blastoconidia and hyphae of Candida albicans with a common epitope recognized by anti-complement receptor type 2 antibodies. 769 55

A new mAb, designated anti-KCA-3, was developed against rat Kupffer cells. The reactivity of anti-KCA-3 was restricted to macrophages with preferential binding to Kupffer cells; only a few macrophages in the spleen, lymph nodes, lungs, and intestine stained with the antibody. A very small number of peritoneal resident and exudate macrophages reacted with the antibody and no reactivity was seen within the thymus, skin, heart, kidneys, brain, peripheral blood, and bone marrow. KCA-3 was expressed predominantly by the Kupffer cells in the periportal region rather than in the centrilobular region of the hepatic lobules. The cells in the portal tract did not stain with the antibody. The staining of the cytosmears and FACS analysis of the Kupffer cell fraction isolated from hepatic sinusoidal cells by centrifugal elutriation revealed that as many as 62% and 49% of the cells were stained with anti-KCA-3, respectively. Immunoelectron microscopic study of the liver indicated that expression of KCA-3 on Kupffer cells was limited to the plasma membrane facing the sinusoid rather than the space of Disse. Immunoprecipitation and SDS-PAGE analysis demonstrated KCA-3 to have a m.w. of approximately 50 kDa under both reducing and nonreducing conditions. After treatment of KCA-3 with N-glycanase, there was no significant change in the m.w., indicating KCA-3 was not highly glycosylated. C3b- and iC3b-mediated rosette formation between Kupffer cells and sensitized SRBC was inhibited by the antibody, implying that KCA-3 functioned as a complement C3 receptor or complement receptor-associated molecule. Furthermore, KCA-3 was eluted from C3b-Sepharose but not HSA-Sepharose after incubation with Kupffer cell lysate, indicating that KCA-3 directly binds C3b. The cell distribution, ligand-binding specificity, and biochemical properties of the protein were found to be different from the complement C3 receptors previously described. Because OX42 (antibody reactive with the rat CR3 receptor) inhibited complement C3-mediated rosette formation with peritoneal resident macrophages but not with Kupffer cells, the findings suggest that C3-mediated binding to Kupffer cells and to peritoneal macrophages is mediated by two different receptors. We conclude that anti-KCA-3 recognizes a novel type of complement C3 receptor preferentially expressed on Kupffer cells.
 ...
PMID:Anti-KCA-3, a monoclonal antibody reactive with a rat complement C3 receptor, distinguishes Kupffer cells from other macrophages. 847 47

Pulmonary surfactant protein A (SP-A), a member of the collectin family, plays an important role in innate immune defense of the lung. In this study, we examined the role of SP-A in modulating complement receptor-mediated phagocytosis. Complement receptors (CR), CR3 (CD11b), and CR4 (CD11c) were expressed at reduced levels on the surface of alveolar macrophages from Sp-a(-/-) compared with Sp-a(+/+) mice. Administration of intratracheal SP-A to Sp-a(-/-) mice induced the translocation of CR3 from alveolar macrophage intracellular pools to the cell surface. Intratracheal challenge with Haemophilus influenza enhanced CR3 expression on the surface of alveolar macrophages from Sp-a(-/-) and Sp-a(+/+) mice, but relative expression remained lower in the Sp-a(-/-) mice at all time points post-inoculation. The effects of SP-A on macrophage and neutrophil CR3 redistribution between intracellular and cell surface pools were restricted to cells isolated from the lung. SP-A augmented CR3-mediated phagocytosis in a manner that was attenuated by N-glycanase or collagenase treatment of SP-A, implicating the N-linked sugar and collagen-like domains in that function. The binding of CR3 to SP-A was calcium dependent and mediated by the I-domain of CR3 and to a lesser extent by the CR3 lectin domain. Mapping of the domains of SP-A that were required for optimal binding to CR3 revealed that the N-linked sugars were more critical than the collagen-like domain or the extent of oligomeric assembly. We conclude that SP-A modulates the cell surface expression of CR3 on alveolar macrophages, binds to CR3, and enhances CR3-mediated phagocytosis.
 ...
PMID:Surfactant protein A modulates cell surface expression of CR3 on alveolar macrophages and enhances CR3-mediated phagocytosis. 1915 16

Short consensus repeat (SCR1-3), the first three SCR modules from N-terminus of type 1 complement receptor (CR1), is expected to accelerate dissociation of complement components and suppress complement activity by binding the main component of complement C4b. In order to clarify the three-dimensional structure, which triggers the activity of SCR1-3 on complement, we constructed an over-expression system in CHO DG44 cells which facilitated mass production of SCR1-3. The mass production was achieved by a two-stage culture system and optimum culture conditions using ASF104N medium and MTX-, NaBu-containing alpha-MEM/10% FBS medium, respectively. The constructed gene of SCR1-3 was confirmed by restriction enzyme digestion and DNA sequence analysis, and the expressed protein by CHO DG44 cells was confirmed by western blotting. The expressed SCR1-3 was proved containing N-linked sugar chain, an important factor to the proper expression of protein, by the cleavage with glycosidase of N-linked oligosaccharide (PNGase F). The suppression effect of the yield protein on complement-mediated inflammation was investigated by haemolytic assay and necrosis assay of stromal cells. Both assays showed that SCR1-3 possessed complement control activity. However, residing sugar chain on SCR1-3 did not show significant difference in the complement control activity.
 ...
PMID:Construction of the plasmid, expression by Chinese hamster ovary cell, purification and characterization of the first three short consensus repeat modules of human complement receptor type 1. 1921 89