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At least 325 records · Page 18Linked to original sources
PubMed1998

Cloning and sequence of a 3.835 kbp DNA fragment containing the HIS4 gene and a fragment of a PEX5-like gene from Candida albicans.

We have isolated the Candida albicans HIS4 (CaHIS4) gene by complementation of a his4-34 Saccharomyces cerevisiae mutant. The sequenced DNA fragment contains a putative ORF of 2514 bp, whose translation product shares a global identity of 44% and 55% to the His4 protein homologs of S. cerevisiae and Kluyveromyces lactis, respectively. Analysis of CaHIS4 sequence suggests that, similarly to S. cerevisiae HIS4, it codes for a polypeptide having three separate enzymatic activities (phosphoribosyl-AMP cyclohydrolase, phosphoribosyl-ATP pyrophosphohydrolase and histidinol dehydrogenase) which reside in different domains of the protein. A C. albicans his4 strain is complemented with this gene when using a C. albicans-S. cerevisiae-Escherichia coli shuttle vector, thus enabling the construction of a host system for C. albicans genetic manipulation. In addition, upstream of the sequenced CaHIS4 sequence, we have found the 3'-terminal half of a gene encoding a PEX5-like protein.

Alcohol Oxidoreductases↗
PubMed1999

Inhibition of cytoplasmic antigen, glucose- 6-phosphate dehydrogenase, by VH-CH1, an intracellular Fd fragment antibody derived from a semisynthetic Fd fragment phage display library.

A library of Fd fragment antibody binding proteins was created by random mutation of 15 nucleotides within the CDRIII region of the immunoglobulin heavy chain gene and displayed as Fd coat protein fusion constructs of M13 phage. The library was screened for those VHbinding sites that bound glucose-6-phosphate dehydrogenase (G6PD). One isolate (DH27bp) inhibited G6PD activity by 85 %. The DH27bpgene was re-engineered, placed in a eukaryotic expression vector having an isopropyl-beta-delta-thiogalactopyranoside (IPTG) inducible promoter, and transfected and then expressed in Chinese hamster V79 cells. G6PD activity was completely inhibited. Removal of IPTG reverted the cell to full G6PD activity. The intracellular dynamics of the G6PD/DH27bpcomplex showed that when the proteasomes of cells expressing DH27bpwere inhibited (N -acetyl-Leu-Leu-norleucinal or lactacystin) G6PD activity increased. Metabolic labelling of newly synthesized IPTG-induced proteins during/absence of proteasomal inhibitors showed that both G6PD and DH27bpare signaled for degradation when the intracellular complex is formed. Furthermore, semi-quantitative RT/PCR demonstrated that G6PD mRNA is upregulated over the time course of G6PD inactivation by DH27bpFd binding protein. These effects were not observed in those cells expressing a non-mutated Fd (UMHC) or in IPTG-treated non-transduced V79 cells. Our results demonstrate that an Fd-based intracellular binding protein can find and disable the function of a specific intracellular target and once the Fd expression is repressed the activity of intracellular targeted protein can revert to normal.

Acetylcysteine↗
PubMed1986

A cloned fragment of HeLa DNA containing consensus sequences of satellite II and III DNA hybridizes with the Drosophila P-element and with the 1.8 kb family of human KpnI fragments.

We have cloned a repetitive EcoRI fragment from the human genome which displays weak homologies with the Drosophila melanogaster transposable P-element. This cloned DNA appeared not to be a mobile element but, instead, a divergent member of human satellite II or III DNAs. We present here the first complete nucleotide sequence of a 1.797 kilobase pair (kb) satellite-like DNA. Moreover, this EcoRI satellite monomer contains a unique sequence of 49 basepairs (bp) that is devoid of the satellite consensus repeat 5'TTCCA3'. Southern hybridization analysis revealed that the cloned insert is closely related to a highly repetitive 1.8 kb KpnI family of tandemly organized satellite DNAs. Thus, the relationships among these satellite DNA families appear to be complex and may be a factor in their copy number, position and spatial organization.

Animals↗
PubMed2004

Simultaneous estimation of a Y-specific fragment, an X-specific fragment and sex determination of forensic studies in real-time PCR.

The human sex test in forensic multiplexes is based on the amelogenin gene on both the X and Y chromosomes commonly used in sex genotyping. In this work sex determination across the quantification of nuclear DNA was achieved by real-time PCR of a segment of the X-Y homologous amelogenin (AMG) gene that allowed the simultaneous estimation of a Y- and an X-specific fragment. The AMG real-time PCR design has been used to quantify a set of forensic casework samples.

Amelogenin↗
PubMed2006

Fragmentation of 2,2,2-triphenylethoxychlorocarbene: evidence for ultrafast fragmentation-rearrangement in excited diazirines.

[reaction: see text] Photolysis of 3-(2,2,2-triphenylethoxy)-3-chlorodiazirine gives 2,2,2-triphenylethoxychlorocarbene which fragments with 1,2-phenyl migration and loss of CO and Cl(-) to yield the 1,1,2-triphenylethyl cation and thence 1,1,2-triphenylethene by proton loss. However, ps and fs laser flash photolysis provides evidence that up to 25% of the alkene product stems from carbocation that arises directly from excited diazirine rather than from the carbene.

Journal Article↗
PubMed2000

Fragment kinetic energies and modes of fragment formation

Kinetic energies of light fragments ( A</=10) from the decay of target spectators in 197Au+197Au collisions at 1000 MeV per nucleon have been measured with high-resolution telescopes at backward angles. Except for protons and apart from the observed evaporation components, the kinetic-energy spectra exhibit slope temperatures of about 17 MeV, independent of the particle species, but not corresponding to the thermal or chemical degrees of freedom at breakup. It is suggested that these slope temperatures may reflect the intrinsic Fermi motion and thus the bulk density of the spectator system at the instant of becoming unstable.

Journal Article↗
PubMed1994

Genotyping of Staphylococcus epidermidis by small-fragment restriction endonuclease analysis and pulsed-field gel electrophoresis of genomic restriction fragments.

Small-fragment restriction endonuclease analysis (SF-REA) was established as a typing tool for Staphylococcus epidermidis. A total of 60 isolates comprising 48 epidemiologically nonrelated strains and 12 putatively linked isolates from 7 patients in 2 wards were analyzed. Nonrelated isolates were characterized by unique fingerprints when DNA was cleaved with EcoRI or ClaI, electrophoretically separated in a polyacrylamide gel, and silver stained. Three blood culture isolates from one patient in an intensive care unit, 4 isolates obtained from a child over a span of 2 weeks, and 5 isolates from 5 newborns in the same ward were grouped into 3 DNA pattern types, indicating identity of sequential isolates from 2 patients and nosocomial transmission of one Staphylococcus epidermidis strain between 5 babies. Results from pulsed-field gel electrophoresis of SmaI and SacII DNA digests and conventional marker systems such as antibiogram and plasmid profile were in accordance with these interpretations, whereas slight variation was observed in the biotypes of several strains. From the results of this study, we conclude that SF-REA is a precise and efficient method for the genotypic characterization of Staphylococcus epidermidis strains that can be used as a rapid and reliable typing tool.

Adult↗
PubMed1983

The quantification of C3 fragments on erythrocytes: estimation of C3 fragments on normal cells, acquired haemolytic anaemia cases and correlation with agglutination of sensitized cells.

A sensitive method is described for the quantification of C3 fragments on erythrocytes. A radiolabelled monoclonal antibody, was used which was directed against a C3d determinant on all forms of cell bound C3. The number of C3 molecules on normal erythrocytes was estimated to be 420 +/- 140. The strength of the antiglobulin test increased from negative to 5+ over a range of only 850 C3 molecules (400-1250). A blood donor with a positive direct antiglobulin test was found to have 4800 molecules per cell whereas three cases of cold haemagglutinin disease with active haemolysis had from 16 000 to 52 020 C3 molecules per cell. This test has an application in the testing of acquired haemolytic anaemia cases with a positive direct antiglobulin test with C3 bound to the cells and in the standardization of sensitized cells used for testing antiglobulin reagents by various serological techniques.

Anemia, Hemolytic↗
PubMed1993

A general method for routine sequencing of cloned DNA fragments using commercial dye primers and its application in sequence analysis of Toxoplasma gondii RH genome fragments.

A generally applicable approach for amplification and subsequent sequencing using commercially available dye primers is described. The polymerase chain reaction primers, one of which is biotinylated, are tagged at their 5' end with sequences of commercial sequencing primers. After purification and strand separation on streptavidin-coated magnetic beads, both strands are sequenced automatically on an Applied Biosystems 373A DNA sequencer using the appropriate standard dye-labeled sequencing primers. This approach is demonstrated on PstI and MnlI DNA fragments from Toxoplasma gondii RH cloned in the in-house developed derivatives of vector pJRtac99.

Animals↗
PubMed1999

[Synthetic ribonucleases. 1. Synthesis and properties of conjugates, containing an RNA-binding fragment based on lysine residues and an RNA hydrolyzing fragment, bearing an imidazole residue].

A series of RNA-hydrolyzing constructions was synthesized on the basis of peptide-like molecules containing residues of L-lysine, histamine and histidine methyl ester. These were shown to hydrolyze RNA effectively at neutral pH values. The in vitro transcript of tRNA(Lys) from human mitochondria and a tRNA-like fragment of RNA of Turnip Yellow Mosaic Virus were used in the experiments. Our chemical RNases quantitatively depolymerize some definite sequences (CA > or = UA > CG >> UC, CC, or CU) in both RNA molecules under optimum conditions. Moreover, no other sites were affected and no statistical hydrolysis was observed even after prolonged RNA incubation with the compounds of this series. The depolymerization rate of the RNA substrates exhibits a complex dependence on the concentration of ions of monovalent metals and on the concentration of the artificial ribonucleases.

Humans↗
PubMed2000

[Bimanual phaco-fragmentation in anterior chamber with chopper and spatula: a new manual phaco-fragmentation option].

PURPOSE/METHOD: We develop an alternative form of manual phacofragmentation for surgery of the cataract with small incision. We have designated it chop-bisection or chop-trisection. The nucleus division is accomplished through sliding, from 6 hours to 12 hours, and counterpressure of a phacochop against other manipulator introduced between the nucleus and the posterior capsule. RESULTS/CONCLUSIONS: The chop-bisection/trisection is an alternative to other forms of nuclear division for small incision surgery, that permits to divide the nucleus in 2 or 3 fragments, introducing instrumental of small dimensions in the anterior chamber, without creating space conflicts or greater traumatism than other described techniques.

Humans↗
PubMed1992

[Fragments of biopolymers containing glycosylphosphates residues. 9. Synthesis of tetra(2-acetamido-2-deoxy-D-glucopyranosyl)triphosphate-- a tetrameric fragment of the capsule antigen from Escherichia coli K51].

Linear tetra(N-acetylglucosaminyl)triphosphate GlcNAc(alpha)-P-3GlcNAc (alpha)-P-3GlcNAc(alpha)-P-3GlcNAc(beta)-ONp, a fragment of the capsular antigen of E. coli K51, was synthesized by the step-by-step approach with the use of the H-phosphonate method, starting the chain from p-nitrophenyl 2-acetamido-4,6-di-O-benzoyl-2-deoxy-beta-D-glucopyranoside. The elongation cycle included the coupling of 2-acetamido-4,6-di-O-benzoyl-2-deoxy-3-O-p-methoxybenzyl-alpha-D-gluc opy ranosyl H-phosphonate with a hydroxyl component in the presence of Me3CCOCl followed by oxidation (I2) and de (methoxybenzylation) (Ce(NH4)2(NO3)6). 2-Acetamido-3,4,6-tri-O-benzoyl-2-deoxy-alpha-D-glucopyranosyl H-phosphonate was employed in the final step. After mild debenzoylation the title tetramer was isolated by anion-exchange chromatography. The data of 1H, 13C and 31P NMR spectra of the synthesized oligomers are discussed.

Acetylglucosamine↗
PubMed2005

Expression of fibrinogen E-fragment and fibrin E-fragment is inhibited in the human infiltrating ductal carcinoma of the breast: the two-dimensional electrophoresis and MALDI-TOF-mass spectrometry analyses.

In the present study, total proteins from a tissue of an infiltrating ductal carcinoma of the breast (IDCA) were compared by the two-dimensional electrophoresis (2D-PAGE) to proteins from an adjacent non-neoplastic breast tissue. Analysis of multiple gels for each sample identified nine proteins present in the tumor sample that were less present in the matched normal adjacent breast tissue and four proteins present at higher levels in the normal tissue. The altered proteins were identified by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and search in protein databases. Protein disulfide isomerase, BiP protein, calreticulin, cathepsin D, inorganic pyrophosphatase, vimentin, apolipoprotein A1 precursor, tropomyosin 4 and beta5-tubulin were identified as being significantly over-expressed in the IDCA with regard to the normal tissue. The expression of fibrinogen E-fragment (known as anti-angiogenic factor) as well as of fibrin E, Pro2619 and actinG1 was found to be inhibited in the tumor sample. The identified proteins might play an important role during malignant transformation, breast cancer progression, and angiogenesis as well as in cellular signaling. This study demonstrates quantitative and qualitative changes in protein abundance between IDCA and normal tissue. The identification of these differentially expressed proteins could lead to a better understanding of the molecular events linked to breast cancer progression.

Breast↗
PubMed2005

[Fragmented red cells are the major cause of spuriously high platelet counts in patients with fragmented red cells when counts are obtained by automated blood cell counter].

Platelet counts measured by automated blood cell counter often show spuriously high values when measuring samples contain particles of equal size to platelets. The major cause of spuriously high platelet counts in samples with fragmented red cells (FRC) is thought to be the FRC themselves. We studied the correlation between FRC and spuriously high platelet counts in 40 patients demonstrating FRC on blood smears. FRC were measured by manual hemocytometry and by flow cytometry using a monoclonal antibody against glycophorin A (GPA method). There was a significant correlation between spuriously high platelet counts and FRC by manual hemocytometry (r=0.60, p<0.001) or FRC by the GPA method (r=0.45, p<0.005). These data suggest that FRC are the major cause of spuriously high platelet counts in samples with FRC.

Adolescent↗
PubMed1977

Artificial hybrid protein containing a toxic protein fragment and a cell membrane receptor-binding moiety in a disulfide conjugate. II. Biochemical and biologic properties of diphtheria toxin fragment A-S-S-human placental lactogen.

The biochemical and biologic properties of a purified disulfide conjugate of diphtheria toxin fragment A and human placental lactogen (toxin A-hPL) have been studied by (a) assaying the ADP-ribosyltransferase activity of the intact conjugate, (b) assaying the binding of the intact conjugate to mammary gland plasma membrane lactogenic receptors, and (c) assaying the effect of the conjugate on the rate of protein synthesis in rabbit mammary gland explants maintained in organ culture. The toxin A-hPL conjugate retains one-third of the NAD+:EF-2 ADP-ribosyltransferase activity of toxin A, and 26% of the hPL-binding activity to lactogenic receptors. Binding activity was demonstrated by radioreceptor assay and by assaying toxin A activity bound to membranes which was competitively displaced by excess hPL. Since the toxin A-hPL conjugate retained activities of its separate subunits, it could be regarded as a structural analogue of nicked diphtheria toxin with replacement of the original membrane-binding chain by another binding chain that is specific for lactogenic receptor. However, the conjugate failed to inhibit protein synthesis in organ-cultured mammary gland explants, although these were sensitive to native diphtheria toxin and could bind hPL. It is concluded from these results that the toxin A-hPL conjugate does not act as a functional analogue of diphtheria toxin with altered receptor specificity, and that the hPL receptor cannot mediate the entry of toxin A or toxin A-hPL from membrane-bound conjugate into the cytosol site of action of toxin A.

Adenosine Diphosphate Sugars↗
PubMedDate not supplied

[Method of conformational calculations of large fragments of nucleic acids. IV. Comparative calculations of dinucleotides by the fragment and atom-atom methods].

Calculations of properties of the dinucleotides for the estimation of the accuracy of our method of group-group interactions for conformational calculations of large polynucleotide fragments were performed. Values of the torsional angles for the close and open conformational states which were found by our method differ by no more than 10 degrees from the conformations which were found by the method of atom-atom interactions. Accuracy of the conformational energy calculations by the group-group method was about 0.5-1.5 kcal/mol for close and open conformation states, respectively. The acceleration factor for conformational properties calculations by our group-group interactions method was about (100 N + 14)/(N + 20), where N is the number of monomers in the chain.

Dinucleoside Phosphates↗
PubMed1996

A theoretical study of hydrophobic fragment and factor constants of Hansch and Leo: estimation of a few non-available fragments and factors.

Hydrophobic fragment constants (f) of benzotriazol-2-yl and Ar-N[CO-]2 systems, and aliphatic H/S polar interaction factors F(H/S) in Cl2CHCONH-Ar and Cl3CCONH-Ar, of Hansch and Leo's constructionist approach, were estimated as 0.69 (standard deviation = 0.17), -1.98, 0.95 and 0.98 respectively. The validity of the first constant has been tested by calculating the log P of compounds not included in the regression.

Cyclopentanes↗