Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sendai virus envelopes have been a useful tool in studying the mechanism of membrane-membrane fusion and have served as a vehicle for introducing foreign molecules (e.g., membrane proteins) into recipient cells. Reconstituted Sendai virus envelopes are routinely obtained following solubilization of virus particles with Triton X-100. This detergent has a low critical micellar concentration which precludes it from being the best detergent of choice in reconstitution studies. Nevertheless, it has remained in use since other detergents such as sodium deoxycholate and sodium cholate rendered the resultant vesicles inactive. Triton X-100 may be suboptimal for studies of some proteins that need be coreconstituted with the viral envelopes. Thus, alternative advantageous detergents, which retain the envelope fusogenic activity, have been sought. In this study we show that the synthetic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (Chaps) effectively solubilizes the Sendai virions, and that the vesicles formed by simple reconstitution protocols appear structurally and biochemically similar to those obtained with Triton X-100. The resultant vesicles retain functional integrity as assessed in both fusion and hemolysis assays. This protocol seems to be useful in sendai envelope-mediated reimplantation of Fc epsilon receptors into the plasma membranes of rat basophilic leukemia cells.
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PMID:Reconstitution of fusogenic Sendai virus envelopes by the use of the detergent chaps. 245 70

A rat monoclonal antibody (MAb) termed RS-II (Ig M) was obtained by syngeneic immunization with rat bladder tumor cells induced by N-butyl, N-hydroxybutylnitrosamine (BBN). Immunocytochemical analysis showed that RS-II is also reactive with mouse, dog and human bladder tumor-cell lines and some other human tumor-cell lines but not myeloma or leukemia cells. Immunohistochemical examination of paraffin-embedded tissues has shown that RS-II is reactive with mouse, rat, dog and human bladder tumors (5/5, 5/5, 1/1, 31/49) and some other tumors, but not with normal human urothelium or normal rat tissues. The antigen is expressed on the majority of low-grade or well-differentiated tumors, but less on advanced, invasive tumors. The immunofluorescence staining pattern of cultured cells was cytoplasmic and filamentous. Immunoblotting revealed that the antigen is a Mr 54,000 to Mr 56,000 protein which was extracted with difficulty from the cultured cells with Triton X-100. The antigen was also detected in the culture supernatant by means of ELISA. Our results suggest that the epitope is expressed on cytoskeletons common to a wide variety of mammalian cells at a certain stage of differentiation.
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PMID:Antigen common to several species, recognized by a rat monoclonal antibody raised against syngeneic rat bladder tumor. 247 3

The glycoprotein gp51 of bovine leukaemia virus (BLV) has been included in an immunostimulating complex (ISCOM). The ISCOM was characterized biochemically in SDS-polyacrylamide gel electrophoresis showing the presence of proteins of estimated molecular weights of 50 and 30 kDa. Immunoblotting showed that gp51 was present in the ISCOM. The BLV-ISCOM had a S-value of 19 S and the electronmicrograph showed the cage-like structure as previously reported for other ISCOMs. About 17% of the total amount of gp51 in the cell culture fluid was recovered in the ISCOMs. The largest loss of gp51 was encountered during the sedimentation of the virus. An ELISA, utilizing monoclonal antibodies to defined epitopes for capture was developed to control the antigenicity of epitopes, e.g. those known to induce neutralizing antibodies. Using this device as a quality control for epitopes the following could be stated. First, ISCOMs prepared from virus solubilized with the non-ionic detergents Triton X-100 or MEGA did not react with neutralizing monoclonal antibodies. In contrast, ISCOMs prepared from virus solubilized with the non-ionic detergents Tween-20, Tween-80 or octyl glucoside did react with the neutralizing antibodies. Second, the neutralizing epitopes were better exposed in ISCOMs than the other epitopes of gp51. In a preliminary experiment it was shown that gp51 in ISCOMs was highly immunogenic.
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PMID:Bovine leukaemia virus ISCOMs: biochemical characterization. 254 75

A type I topoisomerase has been purified more than 4000-fold from calf thymus mitochondria. The enzyme is membrane associated and is effectively solubilized by 1% Triton X-100 treatment of purified mitochondrial inner membranes. This ATP-independent enzyme relaxes positively and negatively supercoiled DNA with delta LK = 1. At low ionic strength, the native enzyme appears to be a monomer (sedimentation coefficient of 4.3 S and Stokes radius of 34 A), but it can form a weakly associated dimer at higher salt concentrations (sedimentation coefficient of 7.0 S and Stokes radius of 47.5 A). The mitochondrial type I topoisomerase is distinguishable from the nuclear enzyme by its (1) pH profile, (2) thermal stability, (3) response to dimethyl sulfoxide and Berenil, and (4) molecular weight. The mitochondrial enzyme is inhibited by elevated concentrations of the bacterial DNA gyrase inhibitor novobiocin, but not nalidixic or oxolinic acids. Sensitivity to N-ethylmaleimide indicates the importance of cysteine for catalytic activity. It is estimated that there are at least five copies of topoisomerase I per mammalian mitochondrion or a minimum of one to two per mitochondrial genome. In a manner similar to that observed with leukemia (nuclear and mitochondrial), calf thymus (nuclear), and HeLa (nuclear) cell type I topoisomerase, the calf thymus mitochondrial enzyme is inhibited by physiological concentrations of ATP.
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PMID:Purification and characterization of a type I DNA topoisomerase from calf thymus mitochondria. 282 74

Poly ADP-ribosylation of two mouse lymphoma cell lines, L5178Y (LS) and the radiation and alkylating agent resistant derivative AII, was investigated by uptake of [3H]NAD by permeabilised cells into acid-precipitable material that was sensitive to phosphodiesterase but insensitive to DNase and RNase. Basal activities in both lymphoma lines were 3-4-fold greater than in mouse L1210 leukaemia cells. However, total endogenous poly (ADP-R) polymerase activity in both L5178Y cell lines, stimulated by a large excess of DNase in the presence of Triton X-100, was less than half the activity in L1210 cells. Doses of N-methyl-N-nitrosourea (MNU) that produced 20-50% survival of colony-forming units increased poly (ADP-R) in both lymphoma lines by only 25% compared with 377% in L1210 cells when synthesis was measured immediately after a 30-min exposure of MNU. During the first 24 h after MNU AII cells produced a peak of activity that was not seen with LS cells. A second peak was seen in both cell lines between 24 and 48 h following MNU. Concentrations of 3-aminobenzamide (3AB) above 2.5 mM inhibited colony-forming ability of lymphoma cells and equally inhibited uptake of [14C]formate into protein, RNA and DNA indicating that 3AB behaves as a general metabolic poison. Concentrations of 3AB in the toxic range of 3-10 mM inhibited poly (ADP-R) synthesis but no degradation of the polymer was observed. Non-toxic concentrations of 3AB potentiated cell killing by MNU to a similar degree in both lymphoma cell lines. In conclusion, we have found little evidence to support the hypothesis that the differential sensitivity of LS and AII is related to poly ADP-ribosylation. Compared with other mouse cells, L5178Y cells appear deficient in poly (ADP-R) polymerase and poly (ADP-R) glycohydrolase activities.
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PMID:Poly (ADP-ribose) metabolism in alkylated mouse L5178Y cells. 299 Jul 53

The effects of various antileukemic agents on DNA replication associated with the nuclear matrix were investigated in CCRF-CEM leukemia cells. Residual nuclear matrices were prepared by sequential treatment of nuclei with 1.5 M NaCl, DNase I, and Triton X-100 and contained 1-5, 10, and 37% of the total nuclear DNA, protein, and phospholipid, respectively. In control cells pulse-labeled for 45 s with [3H]thymidine, the specific activity of nascent DNA was four-fold greater in the nuclear matrix fraction relative to the specific activity of the high salt-soluble (nonmatrix) DNA fraction. Pulse-labeling and reconstitution experiments indicated that this enrichment of newly replicated DNA on the nuclear matrix did not result from aggregation of nascent DNA with the matrix. A 2-h incubation of tumor cells with either 0.1 microM teniposide (VM-26), 0.2 microM VM-26, or 0.5 microM amsacrine (m-AMSA) reduced the relative specific activity of nascent DNA on the nuclear matrix by 59, 61, and 54%, respectively, compared to control cells. In contrast hydroxyurea and cytosine arabinoside, at concentrations that markedly inhibited total nuclear DNA synthesis, did not decrease the relative specific activity of newly replicated DNA on the matrix. The results provide evidence that the antiproliferative effects of the DNA topoisomerase II inhibitors, VM-26 and m-AMSA, are localized on the nuclear matrix of CCRF-CEM leukemia cells.
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PMID:Effects of antileukemia agents on nuclear matrix-bound DNA replication in CCRF-CEM leukemia cells. 334 63

Databases of protein information derived from the analysis of two-dimensional gels have been established from transformed human amnion cells (AMA) and peripheral blood mononuclear cells (PBMCs). A total of 1781 [35S]methionine-labeled AMA proteins (1274 IEF, 537 NEPHGE) and a total of 1311 proteins from PBMC (948 IEF, 363 NEPHGE) were resolved and recorded using computerized (PDQ-SCAN and PDQUEST softwares) two-dimensional gel electrophoresis. AMA and PBMC proteins (total, 454: 301 IEF, 153 NEPHGE) were matched both manually and by the computer. Information entered in the AMA database (in most cases for some major proteins) includes: molecular weight, protein name, HeLa protein catalogue number, mouse protein catalogue number, nuclear proteins, phosphorylated proteins, distribution of proteins in Triton X-100 supernatants and cytoskeletons, proliferation- and transformation-sensitive proteins, cell cycle-specific proteins, mitochondrial proteins, proteins matched in normal human embryonal lung MRC-5 fibroblasts and PBMC cells, heat shock proteins, proteins affected by interferons, cytoskeletal proteins, and the presence of antibody against protein in human sera. Additional information has been entered for the cell cycle-regulated and DNA replication protein cyclin (PCNA). Information entered in the PBMC database includes molecular weight and potential markers for sorted populations of lymphocyte subtypes. For those proteins that have been matched to AMA proteins, information contained in some entries may be transferred from the AMA database.
Leukemia 1988 Sep
PMID:Towards establishing comprehensive databases of cellular proteins from transformed human epithelial amnion cells (AMA) and normal peripheral blood mononuclear cells. 341 26

A new matrix for affinity chromatography using pteroylglutamic acid coupled to an epoxy-activated matrix via hexanediamine resulted in negligible ligand leakage and permitted the purification of soluble and membrane-associated folate-binding proteins from human leukemia cells contained in a human spleen. Two species of membrane-associated folate-binding proteins were purified from the solubilized membrane fraction of the tissue using 2 M guanidine-HCl to elute the proteins from the affinity matrix. The higher molecular weight binding protein had an Mr of approximately 310,000 and the smaller species had an Mr of approximately 28,000 by gel filtration. By SDS-polyacrylamide gel electrophoresis the smaller species of membrane-associated protein had a molecular weight of 35,500, but the molecular weight of the larger membrane-associated species could not be determined by this method because of the high concentration of residual Triton X-100 in the sample which interfered with the silver staining of the gel. Two folate-binding proteins, which by SDS-polyacrylamide gel electrophoresis had molecular weights of 34,500 and 32,000, were purified from the 44,000 X g supernatant fraction of the tissue homogenate by acid elution from the affinity matrix. Despite the different cell components from which the soluble and membrane-associated folate-binding proteins were purified, the amino acid compositions were similar, especially with respect to the apolar amino acids. All these forms of folate-binding proteins had higher affinity for oxidized than for reduced folates, and very low affinity for 5-formyltetrahydrofolate and methotrexate. Although these proteins cross-react with one antiserum raised previously to a folate-binding protein from other human leukemia cells, they do not cross-react with the folate-binding proteins purified from two other sources of human leukemia cells, from human placenta, or from the human KB cell line.
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PMID:Purification, properties, and immunological characterization of folate-binding proteins from human leukemia cells. 347 29

Two tyrosine protein kinase activities have been identified previously to be present in HL-60 leukemia cells during induction of granulocytic and monocytic differentiation with a variety of differentiating agents. We have copurified a membrane-associated tyrosine kinase (p93) and an activity associated with both the cytosol and membrane fractions (p60). Triton X-100 extracts from HL-60 cells treated with dimethyl sulfoxide were subjected to tyrosine-agarose chromatography, polypropyl aspartamide high performance liquid chromatography (HPLC), and HPLC using an antiphosphotyrosine IgG-derivatized column. Overall purification was 2700-fold for p93 and 1800-fold for p60. p60 and p93 are phosphorylated exclusively on tyrosine residues and can use poly(Glu,Tyr)4:1, histone H1 and vasoactive intestinal peptide as substrates. Poly(Glu,Tyr)1:1 and poly(Glu,Ala,Tyr)6:3:1 were less effective substrates for p60 and p93. The activity of p93 was dependent on Mg2+ or Mn2+, whereas p60 was dependent on Mg2+; however, the activity of p60 was stimulated in a synergistic manner by the presence of both Mg2+ and Mn2+, whereas the activity of p93 was not enhanced further by the combination of divalent ions. Both p60 and p93 were immunoprecipitated by an anti-v-src monoclonal antibody but only p93 was immunoprecipitated by an anti-v-fps/fes antibody. V8 protease digestion of p60 revealed one major proteolytic fragment containing phosphotyrosine, whereas V8 protease digestion of p93 produced two major peptides that were phosphorylated on tyrosine residues. These results suggest that, although p93 and p60 may possess some epitopic similarities, they have distinguishing phosphorylation sites. Moreover, p93, in contrast to p60, appears to be strictly associated with granulocytic/monocytic differentiation and related to the cellular fps/fes protooncogene.
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PMID:Purification and characterization of p93fes- and p60src-related tyrosine protein kinase activities in differentiated HL-60 leukemia cells. 348 Feb 86

When leukotriene (LT) A4 was incubated with subcellular fractions of sonicated rat basophilic leukemia (RBL) cells in the presence of glutathione, the enzyme producing LTC4, designated LTC4 synthetase, was found in the 105,000 X g pellet (microsomes) with a 3-fold enrichment in specific activity over that of the sonicate. The identification of the reaction product as LTC4 was confirmed by its identical retention time on reverse-phase HPLC to that of synthetic LTC4, the incorporation of [3H]glutathione into the product, its reactivity in a radioimmunoassay, and its UV absorption spectrum. In contrast, glutathione S-transferase activity, measured spectrophotometrically with 1-chloro-2,4-dinitrobenzene, was detected predominantly in the 105,000 X g supernatant (89%) and also in the microsomes (7%). The microsomal glutathione S-transferase and LTC4 synthetase were solubilized with 0.4% Triton X-102 and separated by DEAE-Sephacel chromatography; the former appeared in the effluent and the latter in the eluate after the addition of 0.16 M NaCl to the equilibration buffer. Solubilized, microsomal glutathione S-transferase was inhibited by S-hexylglutathione with an IC50 of 36 microM and was stable at 40 degrees C for 5 min, whereas LTC4 synthetase was only slightly inhibited (IC50, 2.3 mM) by S-hexylglutathione and retained no activity after incubation at 40 degrees C for 5 min. The partially purified LTC4 synthetase showed a specific activity of 1.34 +/- 0.51 nmol of LTC4 per 10 min per mg of protein (mean +/- SD, n = 9), representing a 10-fold purification from the sonicate and catalyzed the dose- and time-dependent production of LTC4 from LTA4 and glutathione. The apparent Km values for LTA4 and glutathione were estimated by Lineweaver-Burk plots to be 5-10 microM and 3-6 mM, respectively. These results indicate that the conjugation of LTA4 with glutathione to form LTC4 is catalyzed by a unique microsomal enzyme.
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PMID:Isolation and characterization of leukotriene C4 synthetase of rat basophilic leukemia cells. 386 31


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