Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study we report the identification of an antibody in the sera of some patients with autoimmune disease that reacted with a cytoplasmic antigen localized within the Golgi apparatus. The antibody reacted with all tissues investigated, which included pancreas, kidney, testis, liver, thymus, and spleen. In addition, it reacted with some human peripheral circulating lymphocytes, murine peritoneal macrophages, and a variety of tissue culture cell lines, which included HEp-2 cells (human epithelial carcinoma), baby hamster kidney cells, a canine thymus cell line, a primary kidney cell line, Ehrlich ascites cells, Wil-2 cells, and Raji cells. The antigen is located in the same region stained by the histochemical reaction for thiamine pyrophosphatase, thus indicating that the antigen is located within the Golgi apparatus. The antigen was not demonstrated by immunodiffusion of saline extracts of rabbit thymus, pancreas, or liver. The antigen in HEp-2 cells was resistant to RNase A, DNase I, micrococcal nuclease, and to extraction with 0.1 N HC1, but was sensitive to trypsin and Proteinase K. Eight patients with anti-Golgi antibodies have been identified. Six of the eight had systemic lupus erythematosus. Autoantibodies to a Golgi apparatus antigen might serve as a useful biologic marker to study the functional relationship of the Golgi apparatus to lymphocytes and macrophages.
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PMID:Antibodies from patients with autoimmune disease react with a cytoplasmic antigen in the Golgi apparatus. 637 21

The indicator cells with the specificity for the various C3 receptors were prepared using highly purified complement components. The effect of EDTA and divalent cations on the rosette formation of these indicators with human blood cells and lymphoblastoid cells were investigated. B lymphocytes form rosettes with EACl-3b, EACl-3bH, EACl-3bi and EACl-3d irrespective of the presence of cations. PMN and monocytes form rosettes with EACl-3b and EACl-3bH independent of cations, but their formation with EAC1-3bi needs the presence of magnesium. In this case calcium shows a cooperative effect with magnesium. PMN and monocytes do not react with EACl-3d even in the presence of magnesium. Although Raji cells do not react with EACl-3b, they react with EACl-3bH independent of divalent cations. EACm has a similar reactivity to EACl-3bi, and by the treatment with trypsin it becomes similar to EACl-3d.
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PMID:The effect of divalent cations on the rosette formation via C3 receptors. 643 7

A factor which inhibits the binding of 3H-phorbol-12,13-dibutyrate (PDBu) on different types of cells has been partially purified from human placenta. This factor, phorbol ester binding inhibitory factor (PEBIF), is sensitive to pepsin, but resistant to trypsin, heat and acid (pH 3) treatments and can be precipitated by 80% ethanol with no loss of activity. Inhibition occurs both at 37 degrees C and 4 degrees C and is rapid and reversible. Inhibition on human epithelial cells (FL), on mouse erythroleukaemia cells (FELC clone 19-10) and on rat liver cells (IAR clone 6-1 and clone 20) is non-competitive, whereas on IAR clone 6 and clone 6-7 it is competitive. Differentiation of FELC induced by hexamethylene bisacetamide (HMBA) can be inhibited by 12-O-tetradecanoyl phorbol-13-acetate (TPA) only if TPA-sensitive cells are used, and no inhibition was observed with TPA-resistant cells. PEBIF can also inhibit the differentiation induced by HMBA of TPA-sensitive cells and has no effect on the differentiation of TPA-resistant cells. The extent of inhibition of PDBu binding by PEBIF was similar in these two clones. Like TPA, PEBIF can increase 2-deoxyglucose uptake in mouse fibroblasts (BALB/3T3 cells). Thus, TPA and PEBIF share two biological responses; however, PEBIF failed to mimic other TPA effects, such as induction of Epstein-Barr virus from Raji cells, inhibition of intercellular communication and induction of differentiation of human promyelocytic leukaemia cells (HL-60).
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PMID:A phorbol ester-binding inhibitory factor from human placenta. Partial purification, characterization and biological effects. 659 99

The maturation-associated human B cell rosette receptor (MER) for mouse erythrocytes has been solubilized from B cells by mild trypsinization. It specifically agglutinates mouse red cells. Material with hemagglutinating activity partitioned into the lipid-soluble phase of a Folch partition of the trypsin extract was sensitive to phospholipase C and alkali, and on two-dimensional thin layer chromatography, it co-migrated principally with phosphatidylethanolamine (PE). Phosphatidylcholine, the major lipid present, was inactive. The relationship of phospholipid structure to hemagglutinating activity has been described. PE in the crude trypsin extract was associated with unidentified glycoprotein and albumin. Material containing hemagglutinating lipid bound to a wheat germ lectin-Sepharose column and was released by N-acetylglucosamine, indicating that the PE was complexed with glycoprotein. When the crude trypsin extract or eluate from the lectin column was extracted with aqueous phenol, hemagglutinin in the aqueous phase no longer bound to wheat germ lectin-Sepharose; however, albumin was greatly enriched, indicating that some of the PE exists in a complex with albumin. The molar ratio of PE to albumin was approximately 200:1. After delipidation, this albumin (in molar excess) inhibited hemagglutination by PE in the same way as a recently described subclass of serum albumin. Studies with phospholipase-treated B cells were also consistent with PE being the MER. We conclude that MER is PE, existing in a complex containing glycoprotein and a subclass of albumin. The capacity to form rosettes can be transferred to nonrosetting Raji B cells by the complex, but not pure PE, indicating that the proteins may be involved in orienting PE correctly for it to function as the MER.
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PMID:A phosphatidylethanolamine-containing complex on human B cells that mediates rosette formation with mouse erythrocytes. 660 1

The host-directed cleavage of measles virus fusion protein on infected lymphoid cells was studied to understand the mechanism of viral persistence in lymphoid cells in vivo. Several lymphoblastoid cell lines were infected with measles virus, and the viral glycoproteins expressed on the cell's surface were radiolabeled and analyzed for cleavage of fusion (F(0)) to F(1) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Daudi and Ramos lymphoblastoid cells were deficient in their ability to cleave measles virus fusion protein and correspondingly produced low titers of infectious measles virus, Daudi cells being more defective than Ramos cells. In contrast, other lymphoblastoid cells studied, Victor, Raji, Wi-L2, RPMI 8866, and Seraphine, cleaved the fusion polypeptide and made significantly more infectious virus. Despite their defect in cleaving F protein, Daudi cells were able to assemble and release (noninfectious) measles virus particles into the fluid phase. The deficit in Daudi cells was corrected by fusing infected Daudi cells with cleavage-competent cells such as Victor or Raji. Furthermore, the cleavage event performed by competent cells could be mimicked at the plasma membrane by treating infected Daudi cells with trypsin, implicating the role of a plasma membrane enzyme in cleaving F(0) to F(1) during measles virus infection. Hence, lymphoid cells deficient in the plasma membrane enzyme required to cleave F protein are permissive for measles virus, maintain viral gene products, produce mostly noninfectious virus, and fail to place the biologic activity F(1) protein on their surfaces.
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PMID:Failure to cleave measles virus fusion protein in lymphoid cells. 689 82

Highly purified human C3, free of C5 and beta 1H, was used to prepare EAC14oxy23b, EAC14oxy23b' (C3b cells treated with purified C3bINA and beta 1H) and EAC14oxy23d (C3b' cells treated with trypsin). These intermediates were used to assess by rosette formation C3-receptor activity on various cells. The number of cell-bound C3 per C3b, C3b', and C3d cell was quantified by applying 14C-formaldehyde-labeled C3. Human PBL reacted to about the same degree with C3b, C3b', and C3d cells, whereas monocyte-free PBL enriched for B cells interacted preferentially with the C3b' and the C3d cells; human tonsil lymphocytes behaved similarly. The reaction of Raji cells was clearly assessable with C3b cells and was accelerated with C3b' and C3d cells. Daudi cells reacted with C3b' and C3d cells only, in comparison to Raji cells with a much lower activity. Human granulocytes reacted equally well with C3b and C3b' cells, but towards C3d cells they were almost unreactive. Human monocytes formed rosettes with C3b cells, and at a lower level, rosettes with C3b' cells. C3d cells were unreactive. Similar reaction patterns were obtained with guinea pig leukocytes, whereas mouse leukocytes were totally different, since peritoneal macrophages only formed rosettes with human C3b' cells.
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PMID:Qualitative and quantitative assessment of C3-receptor reactivities on lymphoid and phagocytic cells. 721 81

The occurrence and distribution of distinct receptors for three C3 fragments on purified human blood lymphocytes were studied by rosette formation. Indicator cells were bovine, chicken, or sheep erythrocytes (E) bearing up to 100,000 molecules of human C3b (EC3b) without antibody. EC3b was converted to C3bi-bearing-E (EC3bi) with purified C3b inactivator (factor I) and beta1H (factor H), and to C3d-bearing E (EC3d) by treatment of EC3bi with trypsin. Using bovine E (Eb) as indicators, approximately 11% of the lymphocytes bound EbC3b, 6% bound EbC3bi and 2% bound EbC3d. Fractionation of the lymphocytes by adsorption to monolayers of C3-fragment-bearing Eb or by rosetting indicated that most of the cells with receptors for C3b were distinct from those having receptors for C3bi and/or C3d. Cells from two lymphoblastoid cell lines (Raji and Daudi) formed strong rosettes with EC3b, which were weak. 51Cr-labeled E was used as a target in antibody, C3-fragment-bearing E was not lysed by the lymphocytes. However, at suboptimal concentrations of IgG enhancing capacity of the fragments occurred in the order of C3bi greater than C3d greater than C3b. In addition, C3-fragment-bearing cells inhibited the lysis of antibody-coated cells not concluded that target cell bound C3 fragments enhance ADCC by improving contact between target cells and those effector cells which have C3 receptors. Cell-bound C3 effector cells. It is proposed that certain lymphocytes are capable of interacting with C3bi in addition to C3b and C3d and that C3bi and C3d have a greater regulatory effect on their cytolytic function than C3b.
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PMID:Interaction of target cell-bound C3bi and C3d with human lymphocyte receptors. Enhancement of antibody-mediated cellular cytotoxicity. 725 21

Conditioned medium from a human myelomonocytic cell line THP-1 promoted the growth of a wide variety of cell types, i.e., human and mouse myeloid cells (HL-60, U937, K562, and M1), mouse T-cells (EL-4), human B cells (Daudi and Raji), mouse mastocytoma cells (IC-2), human melanoma cells (A375-C6), mouse transformed fibroblast cells (L929), human lung fibroblast cells (TIG-1), and mouse bone marrow fibroblast/stromal-like cells. The growth-promoting activity was acid-labile. The activity was resistant to 50 degrees C for 5 min but completely lost in 5 min at 70 degrees C. The activity was resistant to treatment with trypsin but sensitive to chymotrypsin alpha, Pronase E, and proteinase K, indicating the proteinous nature of this activity. The activity was lost by dithiothreitol and 2-mercaptoethanol. Molecular weight (M(r) 50,000-70,000) was estimated by gel filtration-high performance liquid chromatography. After the sequential anion exchange, hydrophobic, and hydroxylapatite high performance liquid chromatography, the partially purified factor exhibited the same target cell spectrum as the conditioned medium.
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PMID:Human myelomonocytic cell line THP-1 produces a novel growth-promoting factor with a wide target cell spectrum. 846 8

Thirteen monoclonal antibodies submitted to the Third Workshop on Erythrocyte Antigens from the panel "non-specific erythrocyte antigens" were tested for their reactivity with different types of cells. Most of them were defined as specific for adhesion antigens. The CD 44 antibodies 2D3-1, 2D3-2, 2D3-3 and 2D3-4 reacted as expected for CD 44 except their negative reactivity with the myeloid cell line HL 60 and B-cell line Raji. The CD 47 antibodies 2D3-5 and 2D3-6 reacted specific. Only with Raji and T-cell line MOLT 4 the CD 58 antibodies 2D3-7 and 2D3-8 showed reactivity as expected which indicates that they are "CD 58 related". The CD 99 antibody 2D3-9 shows similar results as expected for a CD 99 specific antibody except its high reactivity against Raji. From the RBC-related antibodies 2D3-11 and 2D3-12 the latter becomes completely negative with trypsin treated erythrocytes. The antibody is negative on normal peripheral blood lymphocytes but reacts with transformed cell lines like Raji and MOLT 4. With a view to their reactivity to the cells tested at least 2D3-13 of the Rh-related antibodies seems to be similar to CD 47 antibodies.
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PMID:Flow cytometric investigation of non-specific erythrocyte antigens. 909 24

The GC-rich segment containing GGAGGC (Alu core) is conserved within the RNA polymerase III (pol III) promoters of Alu family sequences. We have shown that the GGAGGC motif functions as a modulator of DNA replication as well as of transcription, and identified the proteins binding to the motif in human HeLa cells. In this study, the Alu core binding proteins were partially purified from human Raji cells by using an Alu core DNA affinity column. Both the proteins thus purified were implied to be subunits of Ku antigen based on the following criteria: The molecular weights of the proteins estimated on gel electrophoreses were 70 and 85 kDa, respectively, under denaturing conditions, while under non-denaturing conditions only one band was observed for the same sample at 150 kDa, probably representing hetero-dimer formed between the 70 and 85 kDa proteins. The sizes and the hetero-dimer formation are reminiscent of the 70 and 80 kDa subunits of Ku antigen (Ku-p70 and Ku-p80). Moreover, the purified proteins were immunoreactive with anti-Ku antibodies, and the specific DNA-protein complex on the Alu core element was cancelled by the anti-Ku antibodies. The nucleoprotein complex showed the same clipping patterns as those of the complex between the Alu core element and an authentically purified Ku antigen after proteolytic cleavage with trypsin and chymotrypsin.
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PMID:Ku antigen binds to Alu family DNA. 950 18


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