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Allogeneic bone marrow grafts carried out after previous administration of antilymphocytic serum alone were attempted in 16 patients. Of these, six had acute myeloblastic leukaemia, four acute lymphoblastic leukaemia, and one a blast cell crisis in polycythaemia vera. Ten of these patients were in an overt phase of the disease and resistant to chemotherapy, while nine had complete agranulocytosis. In five of these patients erythrocyte and leucocyte antigenic markers demonstrated the establishment of the graft. One patient had thalassaemia major, and four others had aplasia of the bone marrow, in one case due to chloramphenicol poisoning and in another to virus hepatitis. The grafts were successful in the last two patients and transformed their clinical condition.No signs of early acute secondary disease were noted in any of the patients, either when the donor had been given antilymphocytic serum or when he was untreated. The grafts had no adoptive immunotherapeutic effect on the acute leukaemia. These observations have clearly shown that antilymphocytic serum has an immunosuppressive effect in man when it is used alone.  相似文献   
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In our previous analysis of the information at binding sites on nucleic acids, we found that most of the sites examined contain the amount of information expected from their frequency in the genome. The sequences at bacteriophage T7 promoters are an exception, because they are far more conserved (35 bits of information content) than should be necessary to distinguish them from the background of the Escherichia coli genome (17 bits). To determine the information actually used by the T7 RNA polymerase, promoters were chemically synthesized with many variations and those that function well in an in vivo assay were sequenced. Our analysis shows that the polymerase uses 18 bits of information, so the sequences at phage genomic promoters have significantly more information than the polymerase needs. The excess may represent the binding site of another protein.  相似文献   
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The interaction between calcium-saturated chicken calmodulin and a peptide corresponding to the calmodulin-binding domain of the chicken smooth muscle myosin light chain kinase has been studied by multinuclear and multidimensional nuclear magnetic resonance methods. Extensive 1H and 15N resonance assignments of calmodulin in the complex have been obtained from the analysis of two- and three-dimensional nuclear magnetic resonance spectra. The assignment of calmodulin in the complex was facilitated by the use of selective labeling of the protein with alpha-15N-labeled valine, alanine, lysine, leucine, and glycine. These provided reference points during the main-chain-directed analysis of three-dimensional spectra of complexes prepared with uniformly 15N-labeled calmodulin. The pattern of nuclear Overhauser effects (NOE) seen among main-chain amide NH, C alpha H, and C beta H hydrogens indicates that the secondary structure of the globular domains of calmodulin in the complex closely corresponds to that observed in the calcium-saturated state of the protein in the absence of bound peptide. However, the backbone conformation of residues 76-84 adopts an extended chain conformation upon binding of the peptide in contrast to its helical conformation in the absence of peptide. A sufficient number of NOEs between the globular domains of calmodulin and the bound peptide have been found to indicate that the N- and C-terminal regions of the peptide interact with the C- and N-terminal domains of calmodulin, respectively. The significance of these results are discussed in terms of recently proposed models for the structure of calmodulin-peptide complexes.  相似文献   
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K Bartsch  R Schneider    A Schulz 《Applied microbiology》1996,62(10):3794-3799
We have isolated and characterized an aspartate transaminase (glutamate:oxalacetate transaminase, EC 2.6.1.1) from the thermophilic microorganism Bacillus stearothermophilus. The purified enzyme has a molecular mass of 40.5 kDa by sodium dodecyl sulfate gel analysis, a temperature optimum of 95 degrees C, and a pH optimum of 8.0. The corresponding gene, aspC, was cloned and overexpressed in Escherichia coli. The recombinant glutamate:oxalacetate transaminase protein was used in immobilized form together with 4-aminobutyrate:2-ketoglutarate transaminase (EC 2.6.1.19) from E. coli for the production of L-phosphinothricin [L-homoalanin-4-yl-(methyl)phosphinic acid], the active ingredient of the herbicide Basta (AgrEvo GmbH), from its nonchiral 2-keto acid precursor 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO). In this new coupled process conversion rates of ca. 85% were obtained with substrate solutions containing 10% PPO by using only slight excesses of the amino donors glutamate and aspartate. The contamination of the reaction broth with amino acid by-products was < 3%.  相似文献   
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A set of growth arrest-specific genes (gas) whose expression is negatively regulated after serum induction has previously been described (C. Schneider, R. M. King, and L. Philipson, Cell 54:787-793, 1988). The detailed analysis of one of them, gas6, is reported here, gas6 mRNA (2.6 kb) is abundantly expressed in serum-starved (48 h in 0.5% fetal calf serum) NIH 3T3 cells but decreases dramatically after fetal calf serum or basic fibroblast growth factor stimulation. The human homolog of gas6 was also cloned and sequenced, revealing a high degree of homology and a similar pattern of expression in IMR90 human fibroblasts. Computer analysis of the protein encoded by murine and human gas6 cDNAs showed significant homology (43 and 44% amino acid identity, respectively) to human protein S, a negative coregulator in the blood coagulation pathway. By using an anti-human Gas6 monospecific affinity-purified antibody, we show that the biosynthetic level of human Gas6 fully reflects mRNA expression in IMR90 human fibroblasts. This finding thus defines a new member of vitamin K-dependent proteins that is expressed in many human and mouse tissues and may be involved in the regulation of a protease cascade relevant in growth regulation.  相似文献   
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