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J Bellatin

Publications and source records attributed to J Bellatin.

8 recordsLinked to original sources
PubMed1997

Fasciola hepatica cysteine proteinases: immunodominant antigens in human fascioliasis.

Fasciola hepatica adult worm cysteine proteinases were active-site, affinity radio-labeled with benzyloxicarbonyl-L-tyrosine-L-alanine diazomethylketone (Z-Tyr125I-Ala-CHN2). Sera from patients with fascioliasis and from rabbits experimentally infected with F. hepatica immunoprecipitated the radiolabeled parasite cysteine proteinases in immunoelectrophoresis assays. Two purified antigens were identified as part of the complex mosaic of antigens immunoprecipitated by the sera of infected patients. These antigens (Fas1 and Fas2) have been shown to be an important part of the Fharc2 precipitin band used for serologic diagnosis in humans and cattle. They showed cysteine proteinase activity with different proteolytic specificities and partial identity in double immunodiffusion assays. The results obtained in this work show that the Fas1 and Fas2 antigens are sensitive and specific antigens for diagnosis of this serious helminthic disease in humans and other susceptible hosts.

Animals↗
PubMed1987

The effects of protein synthesis inhibition, and of mutations rna1.1 and rna82.1, on the synthesis of small RNAs in yeast.

Strains of Saccharomyces cerevisiae have been constructed that possess temperature-sensitive defects in tRNA precursor (pre-tRNA) splicing and which also lack the processing endonuclease that acts at the 3'-terminus of 5 S rRNA and 35 S rRNA precursors (pre-rRNAs). The unspliced pre-tRNAs accumulated by such strains at the nonpermissive temperature are identical in structure to those accumulated by pre-tRNA splicing-defective strains with a functional pre-5 S RNA processing enzyme. The pre-RNA processing activity is therefore not obligatorily involved in maturation of several yeast tRNAs. However, gels of the pulse-labelled RNAs of RNA82+ and rna82.1 strains provide evidence that this enzyme acts upon a few small unstable transcripts that are not 5 S RNA forms. The most prominent of these transcripts on gels was, in wild-type strains, an RNA 145 +/- 2 nucleotides in length.

Cycloheximide↗
PubMed1986

Monoclonal antibodies reacting with multiple epitopes on the human insulin receptor.

Monoclonal antibodies for the human insulin receptor were produced following immunization of mice with IM-9 lymphocytes and/or purified placental receptor. Four separate fusions yielded 28 antibodies, all of which reacted with receptor from human placenta, liver and IM-9 cells. Some antibodies cross-reacted to varying degrees with receptor from rabbit, cow, pig and sheep, but none reacted with rat receptor. At least 10 distinct epitopes were recognized as indicated by species specificity and binding competition experiments. All of these epitopes appeared to be on extracellular domains of the receptor as shown by binding of antibodies to intact cells. In some cases the epitopes were further localized to alpha or beta subunits by immunoblotting. Several antibodies inhibited binding of 125I-insulin to the receptor, some had no effect on binding, and others enhanced the binding of 125I-insulin. It is concluded that these antibodies will be valuable probes of receptor structure and function.

Animals↗
PubMed1982

Changes in the relative proportion of transformation-sensitive polypeptides in giant HeLa cells produced by irradiation with lethal doses of x-rays.

Irradiation of HeLa cells with 1,100 rads (1 rad = 0.01 J/kg = 0.01 Gy) of x-rays yielded a pure population of giant cells 5-7 days after irradiation. These cells do not divide but go through an intermittent DNA synthetic phase. The population of giant cells in S phase (8%) is considerably lower than that of control asynchronous HeLa cells (30%), but 80% of the giant cells go through S phase as determined by 48-hr labeling with [3H]thymidine. Previous studies with high-resolution two-dimensional gel electrophoresis identified 58 [35S]methionine-labeled polypeptides common to human epithelial amnion cells and lung fibroblasts, whose rate of synthesis is sensitive to neoplastic transformation [Bravo, R. & Celis, J. (1982) Clin. Chem. (Winston-Salem, NC) 28, 949-955]. These polypeptides also have been identified in HeLa cells and other transformed human cells such as Detroit 98, Chang liver, Fl-amnion, and WISH-amnion [Bravo, R. & Celis, J. (1982) Clin. Chem. (Winston-Salem, NC) 28, 949-955]. After irradiation of HeLa cells and giant cell formation, the relative proportions of most of the transformation-sensitive polypeptides (43 of 47) reverted to levels similar to those observed in non-tumorigenic cells. This suggests that their relative proportions are dependent on the growth properties of the cells. In particular, the relative proportions of three polypeptides (designated 12g and 60d1 in isoelectric focusing and 27b in nonequilibrium pH gradient electrophoresis) were not affected, indicating that their reduced amounts in transformed cells could reflect a fundamental change that develops during transformation.

Cell Division↗
PubMed1981

[35S]-methionine labelled polypeptides from HELA cells. Coordinates and percentage of some major polypeptides.

A total of 1169 [35S]-methionine labelled polypeptides (855-acidic (IEF) and 314 basic (NEPHGE) from 100 asynchronous human HeLa cells have been separated using high resolution two dimensional gel electrophoresis. Beside numbering these spots, we give for the major polypeptides their coordinates (M.W. and relative mobility respect to beta-actin (IEF) or NEPHGE), and percentage of total protein label. A few major polypeptides have been identified.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

[35S]-methionine labelled polypeptides from secondary mouse kidney fibroblasts: coordinates and one dimensional peptide maps of some major polypeptides.

A total of 1147 [35S]-methionine labelled polypeptides (826 acidic (IEF) and 321 basic (NEPHGE)) from asynchronous secondary mouse kidney fibroblasts have been separated using high resolution two dimensional gel electrophoresis. Beside numbering the spots, we give for the major polypeptides their coordinates (M.W. and relative mobility respect to beta-actin (IEF) or NEPHGE polypeptide 9 (NEPHGE)). By using one dimensional peptide mapping it has been possible to find homologies between several major mouse and HeLa cell polypeptides.

Animals↗