Recombinant glycodelin carrying the same type of glycan structures as contraceptive glycodelin-A can be produced in human kidney 293 cells but not in chinese hamster ovary cells.

We have produced human recombinant glycodelin in human kidney 293 cells and in Chinese hamster ovary (CHO) cells. Structural analyses by lectin immunoassays and fast atom bombardment mass spectrometry showed that recombinant human glycodelin produced in CHO cells contains only typical CHO-type glycans and is devoid of any of the N, N'-diacetyllactosediamine (lacdiNAc)-based chains previously identified in glycodelin-A (GdA). By contrast, human kidney 293 cells produced recombinant glycodelin with the same type of carbohydrate structures as GdA. The presence of a beta1-->4-N-acetylgalactosaminyltransferase functioning in the synthesis of lacdiNAc-based glycans in human kidney 293 cells is concluded to be the cause of the occurrence of lacdiNAc-based glycans on glycodelin produced in these cells. Furthermore, human kidney 293 cells were found to be particularly suited for the production of recombinant glycodelin when they were cultured in high glucose media. Lowering the glucose concentration and the addition of glucosamine resulted in higher relative amounts of oligomannosidic-type glycans and complex glycans with truncated antennae. Human glycodelin is an attractive candidate for the development of a contraceptive agent, and this study gives valuable information for selecting the proper expression system and cell culture conditions for the production of a correctly glycosylated recombinant form.     

Palytoxins: A still haunting Hawaiian curse

Palytoxins are a class of extremely potent non-proteic marine biotoxins, whose main biological target is the Na⁺/K⁺-ATPase. Since its isolation in 1971 from samples of Hawaiian Palythoa spp., palytoxin has drawn scientists’ attention from across the world because of its high toxicity, intriguing chemical structural architecture, and involvement in fascinating ancient Hawaiian folklore. Palytoxins have recently spread also to more temperate areas, such as the Mediterranean Sea causing severe human intoxications. Over the past years our scientific work has brought to light the occurrence of new palytoxin analogs by extensive NMR investigation and a new liquid chromatography tandem mass spectrometry method set up following the Mediterranean toxic outbreaks.     

Phosphonoglycoprotein from Metridium senile--heterogeneity of glycoproteins containing aminoethylphosphonic acid.

1. After separation by SDS gel-chromatography, analysis of AEP-containing glycoproteins from M. senile, indicated 66% amino acids with 220 AEP res./1000 res. and 30% carbohydrate for high mol. wt (greater than 10(7) forms and 80% amino acids with 25-50 AEP res./1000 res. and 10% carbohydrate for low mol. wt (2-4 x 10(4) forms. 2. Uronic acids, sulfate, lipid, and sialic acids were absent. 3. Mild base digestion released AEP-hexosamine containing oligosaccharides and destroyed ser-thr residues in the high mol. wt components. 4. Phosphonoglycoproteins appear to be acidic connective tissue components with AEP linked to hexosamine containing oligosaccharide side chains.     

Localization of the mouse kidney disease (kd) gene to a YAC/BAC contig on Chromosome 10

Mice that are homozygous for the kidney disease (kd) gene on Chromosome (Chr) 10 spontaneously develop a progressive and fatal interstitial nephritis. The disease phenotype is similar to that of the human disease, juvenile nephronophthisis. Using a backcross and intercross breeding strategy and analysis of over 900 resultant progeny, this genetic locus has now been mapped to a minimal co-segregating region of approximately two megabases between D10Mit 193 and D10Mit 38. The location assigned to kd by this study is over 3 cM from the current Mouse Genome Database location. The entire interval has been cloned in yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAC) clones. Recombinant analysis has permitted assignment of 13 Mit microsatellite markers to positions near or within the region. Two new markers have been identified by using single-strand conformation polymorphism (SSCP) analysis of sequenced BAC ends. Several BAC end sequences align with human BAC clones from Chr 6q21 that contain NR2E1, Snx3, and Ros1. Three murine genes, CD24a, fyn, and ColX reported to map in or near the kd region as defined by this study have been evaluated. Though not definitely excluded, they appear to be unlikely candidates. Received: 23 July 1999 / Accepted 23 June 2000     

Changes in nurse cell nuclei during synchronous infection with Trichinella spiralis

The rate of enlargement of nuclei was determined on 4-microns-thick sections of synchronously infected mouse thigh muscle. Normal muscle nuclei had a geometric mean volume of 84 microns and a range of 42-170 microns 3. At days 5, 6, 7, 8, and 10 and 6 mo after infection, mean nuclear volume was 177 (100-315) microns 3, 254 (140-462) microns 3, 278 (172-447) microns 3, 681 (407-1,138) microns 3, 512 (326-804) microns 3, and 509 (298-870) microns 3, respectively. Size of nuclei for any given day followed a log normal distribution. On days 7 and 8 after infection, 31% of enlarged nuclei had 2 nucleoli, whereas only 15% had 2 nucleoli on day 10. One percent of enlarged nuclei in 6-mo-old nurse cells had double nucleoli. The number of enlarged nuclei in 6-mo-old nurse cells was determined from serial sections of infected tongue muscle. Each nurse cell contained an average of 40 enlarged nuclei. Sixty-four percent of nurse cells examined (n = 55) had between 30 and 60 enlarged nuclei. However, there was great variation in the range (7-142). These results are discussed in relation to the development of the nurse cell.     

Small-scale migratory behavior of three facultative soaring raptors approaching a water body: a radar study investigating the effect of weather,topography and flock size

Journal of Ethology - Water bodies are considered a barrier to the migration of large bird species, mainly because of the absence of thermals that these birds heavily rely on to move large...     

The Lewis x epitope is a major non-reducing structure in the sulphated N-glycans attached to Asn-65 of bovine pro-opiomelanocortin

The N-terminal glycopeptide of pro-opiomelanocortin (POMC),designated as the 16K fragment, is highly conserved throughoutvertebrates from amphibians to mammals and is likely thereforeto have an important functional role. In this paper, we reportthe first structural characterization of N-glycans attachedto asparagine-65 of a 16K glycopeptide. The 16K fragment wasisolated from bovine pituitaries and the N-glycans were analysedusing fast atom bombardment mass spectrometry together withsugar and linkage analysis. Sulphated-N-acetylgalactosamine-cappedantennae, typical of the pituitary glycohormones, were presentin the major acidic components. The POMC oligo-saccharides aredistinct from those of the pituitary glycohormones because thesulphate is exclusively located on the 3-arm of biantennarystructures and, in addition, a significant proportion of themolecules carry the Lewis x epitope. It is probable that thesedifferences reflect the absence of a tripeptide motif in POMCwhich fully conforms to the criteria previously defined forthe recognition sequence for the N-acetylgalactosamine transferasethat is specific for the pituitary glycohormones [Smith andBaenziger (1992) Proc. Natl. Acad. Sci. USA, 89, 329–333].It remains to be seen whether the Lewis x epitope is involvedin selectin-mediated events, but previous studies suggest thatthe sulphated moieties are unlikely to play a major role inclearance. The Lewis x epitope is also present in the neutralN-linked oligosaccharides, together with a variety of otherantennae including a rarely found fucosylated GalNAc-GlcNAcstructure. FAB-MS glycoprotein Lewis x POMC sulphated-GalNAc