Fucosyltransferase expression in human platelets and leucocytes

The activities of -2-l-fucosyltransferase and -3-l-fucosyltransferase were measured in human platelets and leucocytes from normal donors, -2-l-Fucosyltransferase was found in platelets but not in leucocytes. In contrast -3-l-fucosyltransferase was not detected in platelets but was present in leucocytes where it was demonstrated in the neutrophil, monocyte and lymphocyte fractions.     

Enzymic synthesis,chemical characterisation and Sda activity of GalNAcß1-4[NeuAcα2-3]Galß1-4GlcNAc and GalNAcß1-4[NeuAcα2-3]Galß1-4Glc

The tetrasaccharides GalNAcß1-4[NeuAc2-3]Galß1-4Glc and GalNAcß1-4[NeuAc2-3]Galß1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3-sialyllactose (NeuAc2-3Galß1-4Glc) and 3-sialyl-N-acetyllactosamine (NeuAc2-3Galß1-4GlcNAc). The structures of the products were established by methylation and¹H-500 MHz NMR spectroscopy. In Sd^a serological tests the product formed with 3-sialyl-N-acetyllactosamine was highly active whereas that formed with 3-sialyllactose had only weak activity.     

Purification of the Lewis blood-group gene associated α-3/4-fucosyltransferase from human milk: an enzyme transferring fucose primarily to Type 1 and lactose-based oligosaccharide chains

A soluble Lewis blood-group gene associated -3/4-L-fucosyltransferase has been purified from human milk by a series of steps involving hydrophobic chromatography on Phenyl Sepharose 4B, ion exchange chromatography on CM-Sephadex C-50, affinity chromatography on GDP-hexanolamine Sepharose 4B and gel filtration on Sephacryl S-200. The first step separated -3-L-fucosyltransferase activity directed towardsN-acetylglucosamine in Type 2 (Gal1-4GlcNAc-R) acceptors from an -3/4-fucosyltransferase fraction acting on both Type 1 (Gal1-3GlcNAc-R) and Type 2 acceptors. Further purification of this latter fraction on CM-Sephadex and GDP-hexanolamine Sepharose gave a single peak of fucosyltransferase activity that catalysed the addition of fucose toN-acetylglucosamine in both Type 1 and Type 2 acceptors and to theO-3 position of glucose in lactose-based oligosaccharides. The enzyme preparation at this stage resembled previously described -3/4-fucosyltransferase preparations purified from human milk. However, gel filtration of this preparation on Sephacryl S-200 or Sephadex G-150 separated further amounts of -3-fucosyltransferase activity acting solely on Type 2 acceptors and left a residual -3/4-fucosyltransferase that retained strong -4 activity with the Type 1 acceptor, lacto-N-biose 1, and -3 activity with 2-fucosyllactose, but had relatively little -3 activity withN-acetyllactosamine and virtually no capacity to transfer fucose to glycoproteins withN-linked oligosaccharide chains having unsubstituted terminal Type 2 structures.     

RNA 2 of tobacco rattle virus strain TCM encodes an unexpected gene.

The sequence of the 3'-terminal 1210 nucleotides of RNA 1 and the complete sequence of 3389 nucleotides of RNA 2 of tobacco rattle virus (TRV) strain TCM has been deduced. The sequence of the 3'-terminal 1099 nucleotides of RNAs 1 and 2 was found to be identical. Thus the genome of this TRV strain is partially diploid, encoding a 16K protein in both RNA 1 and RNA 2. The sequence that is unique to RNA 2 contains two open reading frames: the coat protein cistron and a cistron for a 29.1K protein, which shows no homology with the RNA 1 encoded 28.8K protein. cDNA probes corresponding to these two open reading frames cross-hybridized to pea early-browning virus RNA 2, but not to RNA 2 of five other tobraviruses tested.     

Mutation analysis of the cystic fibrosis transmembrane regulator gene in native American populations of the southwest

We report DNA and clinical analyses of cystic fibrosis (CF) in two previously unstudied, genetically isolated populations: Pueblo and Navajo Native Americans. Direct mutation analysis of six mutations of the CFTR gene--namely, delta F508, G542X, G551D, R553X, N1303K, and W1282X--was performed on PCR-amplified genomic DNA extracted from blood samples. Haplotype analyses with marker/enzyme pairs XV2c/TaqI and KM19/PstI were performed as well. Of the 12 affected individuals studied, no delta F508 mutation was detected; only one G542X mutation was found. None of the other mutations was detected. All affected individuals have either an AA, AC, or CC haplotype, except for the one carrying the G542X mutation, who has the haplotype AB. Clinically, six of the affected individuals examined exhibit growth deficiency, and five (all from the Zuni Pueblo) have a severe CF phenotype. Four of the six Zunis with CF are also microcephalic, a finding not previously noted in CF patients. Our DNA data have serious implications for risk assessment of CF carrier status for these people.     

Effect of carbon source on conidiogenesis in fonsecaea dermatitidis,agent of chromomycosis

Hormiscium dermatitidis Kano is a well known etiological agent of cutaneous and generalized chromomycosis. However, the generic designation of this fungus has long been a much debated question. The results of the present study of the type culture ATCC 28869 indicate that the fungus is polymorphic, producing a Phialophora state in media containing glucose or maltose and a Cladosporium state in media containing galactose or melibiose. Morphologically and developmentally this chromomycotic agent is closely related to Fonsecaea pedrosoi (Brumpt) Negroni and should be classified as Fonsecaea dermatitidis (Kano) Carrión.     

Die Aktivität der Polyphenoloxydase als Erbmerkmal und ihre Beziehung zur genetisch bedingten Krankheitsdisposition beim Tabak

Zusammenfassung Der Charakter der Polyphenoloxydase-Aktivität als Erbmerkmal wurde aus folgenden Tatsachen geschlossen: Der Unterschied in der Aktivität dieses Fermentes zwischen 2 Sorten blieb über die ganze Vegetationszeit erhalten und wiederholte sich in ihren Nachkommen. In der F₁ zeigte sich deutliche Dominanz der geringeren Aktivität.Es besteht kein Zusammenhang zwischen Polyphenoloxydase-Aktivität und Anfälligkeit fürPeronospora tabacina, denn beim Vergleich je einerPeronospora-resistenten und einer anfälligen Sorte war einmal die anfällige und einmal die resistente die fermentaktivere. Die Unterschiede in der Aktivität der Polyphenoloxydase ließen also kein Prinzip erkennen.Zwischen der Polyphenoloxydase-Aktivität und der Y-Virus-Anfälligkeit dagegen konnte ein deutlicher Zusammenhang festgestellt werden. Die Unterschiede in der Aktivität der Polyphenoloxydase je einer Y-Virus-resistenten und einer anfälligen Sorte verhielten sich gleichsinnig: Die resistenten hatten eine höhere Polyphenoloxydase-Aktivität als die anfälligen Sorten.Die Frage nach der Art des Zusammenhangs zwischen Y-Virus-Disposition und Polyphenoloxydase-Aktivität wurde diskutiert: Es kann kein ursächlicher sein in der Weise, daß Y-Virus-Anfälligkeit von der Polyphenoloxydase-Aktivität abhänge, sondern er muß nach den vorliegenden Versuchsergebnissen als indirekter gedeutet werden derart, daß beide Erbmerkmale, Y-Virus-Anfälligkeit und Polyphenoloxydase-Aktivität von einer gemeinsamen, gengesteuerten dritten Größe abhängen. Die Polyphenoloxydase-Aktivität wird damit als bloßes Anzeichen der physiologischen Aktivität der betreffenden Sorte betrachtet, ohne selbst einen direkten Einfluß auf die Krankheitsdisposition zu haben.

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Summary consequent on the following facts polyphenoloxidase activity proved to be a hereditary quality: The difference of activity between two varieties endured during the whole vegetation time and replicated in their descendants. In F₁ generation dominance of lower activity appeared.There is no relation between polyphenoloxidase activity and susceptibility toPeronospora tabacina, for comparing everyPeronospora susceptible variety with a resistent one, no regularity could be observed: Once the susceptible variety and another time the resistant possessed the higher enzyme activity.Between polyphenoloxidase activity and Y Virus disposition a clear relation became evident: The resistant varieties possessed a higher activity of this enzyme than the susceptible ones.The question is discussed how to explain this relation between polyphenoloxidase activity and Y Virus disposition. It can not be a causal one in this way that Y Virus susceptibility should depend on polyphenoloxidase activity. Relation must be an indirect one in this way that both hereditary qualities: Y Virus and oxidase activity depend on the same third gene-dependant but unknown quantity. Thus polyphenoloxidase activity is considered to act only as an indicator of physiological processes in the plant without itself having a direct influence on the disposition to Y Virus disease.