The oncofetal J28 epitope involves fucosylated O-linked oligosaccharide structures of the fetoacinar pancreatic protein

The fetoacinar pancreatic protein (FAP), characterized by themAb J28, is an oncofetal form of bile salt dependent lipase(BSDL), the expression of which is related to pancreatic differentiationand neoplastic processes. Because the J28 epitope, recognizedby imAb J28, is suggested to be dependent upon carbohydrates,we have attempted to gain information about the structure ofthis epitope. Indeed, treatment of FAP with sodium periodateabolished the reactivity of the protein to mAb J28, which demonstratesthe implication of oligosaccharides in the structure of theJ28 epitope. FAP offers both O-linked and N-linked carbohydratestructures, of which, as we have determined, one is involved.Peptides obtained after cyanogen bromide cleavage were desialylatedthen separated by affinity chromatography on an immobilizedpeanut agglutinin agarose column. The peptide retained on thiscolumn carried out the reactivity with the mAb J28. Althoughsome differences in amino acid analysis were observed, the N-terminalsequence of this peptide correlates with that of the C-terminalpart of the enzyme. Carbohydrate analysis of the peptide bearingthe J28 epitope revealed fucose, galactose, N-acetylgalactosamine,N-acetylglucosamine, and N-acetylneuraminic acid. The competitionobserved between mAb J28 and Ulex europaeus I lectin for bindingto the J28 epitope suggested that fucose residue a (1–2)linked to a galactose residue was implicated in the structureof the J28 epitope. Alternatively, the loss of the mAb J28 reactivityupon treatment of FAP either with bovine kidney or bovine epididymisfucosidase was observed indicating that fucose residues linkedat the     

Purification and Characterization of a Human Brain Galectin-1 Ligand

Abstract: Our previous studies have characterized an endogenous lectin from human brain identified as galectin-1. A soluble ligand of galectin-1 was purified from human brain by affinity chromatography and preparative electrophoresis. The purified ligand (termed HBGp82, for human brain galectin-1-binding polypeptide of 82,000 daltons) has an apparent molecular mass of 82 kDa and is glycosylated by N -linked biantennary complex structures. HBGp82 was partially characterized by microsequencing of peptide fragments. Similar peptides were found in a heat shock of protein of 90,000 daltons, hsp90. However, comparison of apparent molecular weights and matrix-assisted laser desorption mass spectrometry clearly showed that HBGp82 differs to some degree from hsp90.     

Phosphinothricin stimulates somatic embryogenesis in grape (Vitis sp. L.)

The effect of phosphinothricin concentration on embryo production from an embryogenic callus of Chancellor (Vitis L. complex interspecific hybrid) was tested. Embryogenic callus was cultured on medium supplemented with nine phosphinothricin concentrations (0, 0.1, 0.5, 1, 1.5, 2, 3, 5, and 10 mg/l). The highest number of embryos per plate was observed at 0.5 mg/l phosphinothricin. The use of phosphinothricin to stimulate embryo production did not affect embryo germination and plantlet formation. Three germination techniques were compared. Embryo dehydration or growth on Transfergelsolidified medium gave higher germination rates than chilling treatments. Most germinated somatic embryos produced secondary embryos from the hypocotyl after a few weeks of culture. Regardless of the germination technique, the plantlet conversion rate was very low.Abbreviations AC activated charcoal - 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzylaminopurine - MS Murashige and Skoog (1962) basal medium - NN Nitsch and Nitsch (1969) medium - PPT phosphinothricin     

Calmodulin during development and metamorphosis in urodelan amphibians

Calmodulin isolated and purified to homogeneity from young larvae is very similar to that obtained from adult Pleurodeles waltlii and these proteins are almost identical to previously described vertebrate calmodulins. During P. waltlii development, an increase in total individual calmodulin content is observed after the heart beating stage. In dorsal axial muscle, calmodulin level which is very high at the beginning of larval life (premetamorphosis) decreases strikingly in the first part of prometamorphosis. Such an evolution is observed in Ambystoma mexicanum too. Then, a significant increase occurs during metamorphosis. In contrast, calmodulin level in P. waltlii cardiac ventricular muscle increases continuously from hatching to the end of metamorphic climax. Thyroxine treatment which promotes precocious metamorphosis in P. waltlii and experimental metamorphosis in neotenic A. mexicanum, induces a rapid and significant increase in muscle calmodulin concentration.     

Effects of progestins and antiprogestins on mitochondria in uterine glandular cells in the rat

Summary The administration of progesterone to ovariectomized rats induces an increase in the volume density (Vv) of the mitochondria and the appearance of giant mitochondria in the uterine glandular cells. This experimental model, including a stereological analysis, allowed us to investigate and quantify a direct effect of progesterone on a well-defined cellular structure without the intervention of estrogen in a priming phase. Synthetic compounds, promegestone, gestrinone and RU 38486, were tested in this model either in place of progesterone or simultaneously with progesterone. The potent progestomimetic activity of promegestone was confirmed by the proliferation of giant mitochondria and a high Vv value for the mitochondria, the two other compounds being inactive even at higher doses. At lower doses, gestrinone and RU 38486 partially inhibit the action of progesterone and at higher doses they both show a complete antagonist effect by preventing the development of the mitochondria.     

Assignment of the gene for uroporphyrinogen decarboxylase to human chromosome 1 by somatic cell hybridization and specific enzyme immunoassay

Summary A specific enzyme immunoassay of uroporphyrinogen decarboxylase was developed and applied to the detection of the human enzyme in man-rodent somatic cell hybrids. This method allowed to assign the gene for uroporphyrinogen decarboxylase to human chromosome 1.     

Genetic and biosynthetic studies of families carrying hemoglobin J α Mexico: Association of α-thalassemia with Hb J

Summary Hemoglobin J Mexico, an chain mutant, was studied in eight unrelated Algerian families. The quantities of the abnormal hemoglobin in 116 subjects are trimodally distributed: 55% in homozygotes, 31% and 38% in heterozygotes. Both hematological data and the / chain biosynthetic ratio are normal in heterozygotes with 31% Hb J and in homozygotes. In contrast, the MCV and MCH as well as the / biosynthetic ratio are slightly reduced in heterozygotes with 38% Hb J and in their relatives carrying Hb A. The elevated expression of ^J chains in heterozygotes with 38% Hb J may be due to an thalassemia gene trans to the ^>J locus.     

Molecular and functional anomalies in two new mutant glucose-phosphate-isomerase variants with enzyme deficiency and chronic hemolysis

Summary Two new deficient glucose-phosphate-isomerase (GPI) variants have been described in patients suffering from severe chronic hemolytic anemias. The patients' parents were consanguineous, such that the patients were true homozygotes for the mutated GPI genes. In both cases the main cause of the defect in enzyme activity was molecular instability of the mutated GPI molecules, their catalytic activity being nearly normal.GPI Paris was characterized by a slow electrophoretic migration and, above all, a drastically altered affinity for the substrates glucose-6-phosphate (decreased) and fructose-6-phosphate (increased). GPI Enfants malades exhibited a slightly reduced electrophoretic mobility, an abnormal curve of the activity in function of pH, and an abnormal ratio of maximal velocity in the backward direction (fructose-6-phosphate»glucose-6-phosphate) to that in the forward direction (glucose-6-phosphate»fructose-6-phosphate).No clear relation could be proved between the kinetic abnormalities of the mutant GPI variants on the one hand and the metabolic changes of the GPI-deficient red cells and the severity of hemolysis on the other.Finally we emphasized the possible role of the impairment of hexosemonophosphate pathway in the reduction of viability of the GPI-deficient red cells.