The Glycosylation Capacity of Insect Cells

It is generally accepted that insects primarily synthesise oligomannosidic and paucimannosidic N-glycan structures. Indeed, insects’ capability to produce human-like complex type N-glycans has been a matter of controversy for a number of years. The relative or complete lack of these structures was primarily attributed to low (or undetectable) activities of the glycosyltransferases needed to drive the synthesis of hybrid and complex type N-glycans (i.e., b-1,2-N-acetylglucosaminyltransferases I and II, b-1,4-galactosyltransferase, a-2,3- and a-2,6-sialyltransferases). Recent developments, fuelled by availability of genomic sequences and by advances in relevant methodologies, have shed some light on the subject, with a few unexpected twists. The identification of a transmembrane/Golgi hexosaminidase, an enzyme which removes a non-reducing N-acetylglucosamine residue during N-glycan biosynthesis, has demonstrated that the synthesis of complex-type N-glycans is actively and deliberately being prevented in insects. On the other hand, the characterisation of an active a-2,6-sialyltransferase in Drosophila, combined with the occurrence of sialylated N-glycan structures as detected in a detailed analysis of Drosophila embryos, has clearly shown that insects can, and need to, synthesise low levels of these structures. The current understanding of the insect N-glycan biosynthetic pathways taking place in Golgi apparatus and trans-Golgi network are elaborated and discussed

10Be i molekulska stanja

The 10Be excitation energy spectra have been obtained from the inclusive and coincident measurements of the reactions: 7Li +7Li at E0 = 8 and 30 MeV and 9Be +7Li at E0 = 52 MeV. Contributions of the 10Be states below 12 MeV in excitation have been observed. Decays of the states at 9.6, 10.2 and 11.8 into a +6He and, for the first time, into a +6He* have been found. The results are discussed in addition to the other experimental data and recent theoretical predictions. Proposals for future measurements to search for exotic structures in carbon nuclei are also made.Proučavamo ekscitacijske energijske spektre 10Be iz inkluzivnih i koincidentnih mjerenja reakcija 7Li +7Li na E0 = 8 i 30 MeV, te 9Be +7Li na E0 = 52 MeV. Opaženi su doprinosi stanja 10Be u energiji uzbude do 12 MeV. Nađeni su raspadi stanja na 9.6, 10.2 i 11.8 MeV na α +6He te, po prvi put, na α +6He∗. Ovi se rezultati razmatraju zajedno s ostalim eksperimentalnim podacima i novijim teorijskim predviđanjima. Predlažu se buduća mjerenja u kojima bi se tražila stanja lakih jezgara egzotične građe

10Be i molekulska stanja

The 10Be excitation energy spectra have been obtained from the inclusive and coincident measurements of the reactions: 7Li +7Li at E0 = 8 and 30 MeV and 9Be +7Li at E0 = 52 MeV. Contributions of the 10Be states below 12 MeV in excitation have been observed. Decays of the states at 9.6, 10.2 and 11.8 into a +6He and, for the first time, into a +6He* have been found. The results are discussed in addition to the other experimental data and recent theoretical predictions. Proposals for future measurements to search for exotic structures in carbon nuclei are also made.Proučavamo ekscitacijske energijske spektre 10Be iz inkluzivnih i koincidentnih mjerenja reakcija 7Li +7Li na E0 = 8 i 30 MeV, te 9Be +7Li na E0 = 52 MeV. Opaženi su doprinosi stanja 10Be u energiji uzbude do 12 MeV. Nađeni su raspadi stanja na 9.6, 10.2 i 11.8 MeV na α +6He te, po prvi put, na α +6He∗. Ovi se rezultati razmatraju zajedno s ostalim eksperimentalnim podacima i novijim teorijskim predviđanjima. Predlažu se buduća mjerenja u kojima bi se tražila stanja lakih jezgara egzotične građe

Development of a new neutron probe for borehole research

Neutronska proba za ispitivanje naftnih bušotina razvijena je na Institutu Ruđer Bošković u okviru HRZZ projekta IP-2018-01-4060 \u27\u27Nove primjene 14 MeV neutrona\u27\u27. U ovom istraživanju ispitane su daljnje mogućnosti redukcije šuma u mjerenju C/O omjera metodom pridružene alfa čestice. Mješavina kvarcnog pijeska i grafitnog praha korištena je kao materijal od interesa , dok su plastične bočice ispunjene dizel gorivom korištene kao šum (smetnja) i predstavljaju tekućinu unutar naftne bušotine (npr. nafta). Podjela alfa detektora na četiri jednaka segmenta, omogućila je podjelu volumena oko osi neutronske probe na četiri kvadranta. Materijal od interesa i dizel smješteni su u različite kvadrante i pokazano je da su C/O vrijednosti u slučajevima kad je smetnja prisutna unutar statističke greške u odnosu na slučaj kada smetnje nema.The neutron probe for testing oil wells was developed at the Ruđer Bošković Institute within the HRZZ project IP-2018-01-4060 "New applications of 14 MeV neutrons". In this study, further possibilities of noise reduction in C/O ratio measurement by the associated alpha particle method were investigated. A mixture of quartz sand and graphite powder was used as the material of interest, while plastic bottles filled with diesel fuel were used as noise (interference) and represent the liquid inside the oil well (e.g. oil). Dividing the alpha detector into four equal segments, allowed portioning the volume around the neutron probe axis into four quadrants. The material of interest and diesel were located in different quadrants and it is shown that the C/O values in cases where interference is present are within statistical errors compared to the case where there is no interference

Eksperimentalni dokazi (pokazatelji) molekulske strukture lakih jezgri

Experimental studies of the cluster structures in 9,10Be and 13,14C have been performed. Evidence for the α+5He decay of 9Be excited states, α+6He decays of 10Be∗ , α+9Be decay of 13C ∗ and for the decays of 14C ∗ into α+10Be were found. These decay processes indicate the cluster structures of the excited states. The results are compared with recent suggestions for the presence of molecule-like structures based upon α-particles and valence neutrons in Be and C isotopes.Eksperimentalno smo proučavali nakupinske strukture u 9,10Be i 13,14C. Našli smo α+5He raspad uzbuđenog stanja 9Be, α+6He raspad 10Be∗ , α+9Be raspad 13C ∗ te raspad 14C ∗ u α+10Be. Ovi procesi ukazuju na nakupinske strukture uzbuđenih stanja tih jezgri. Ishode mjerenja uspoređujemo s novim objašnjenjima o prisutnosti molekulama-sličnih struktura zasnovanim na α-česticama i valentnim neutronima u izotopima Be i C

Eksperimentalni dokazi (pokazatelji) molekulske strukture lakih jezgri

Experimental studies of the cluster structures in 9,10Be and 13,14C have been performed. Evidence for the α+5He decay of 9Be excited states, α+6He decays of 10Be∗ , α+9Be decay of 13C ∗ and for the decays of 14C ∗ into α+10Be were found. These decay processes indicate the cluster structures of the excited states. The results are compared with recent suggestions for the presence of molecule-like structures based upon α-particles and valence neutrons in Be and C isotopes.Eksperimentalno smo proučavali nakupinske strukture u 9,10Be i 13,14C. Našli smo α+5He raspad uzbuđenog stanja 9Be, α+6He raspad 10Be∗ , α+9Be raspad 13C ∗ te raspad 14C ∗ u α+10Be. Ovi procesi ukazuju na nakupinske strukture uzbuđenih stanja tih jezgri. Ishode mjerenja uspoređujemo s novim objašnjenjima o prisutnosti molekulama-sličnih struktura zasnovanim na α-česticama i valentnim neutronima u izotopima Be i C

The Glycosylation Capacity of Insect Cells

It is generally accepted that insects primarily synthesise oligomannosidic and paucimannosidic N-glycan structures. Indeed, insects’ capability to produce human-like complex type N-glycans has been a matter of controversy for a number of years. The relative or complete lack of these structures was primarily attributed to low (or undetectable) activities of the glycosyltransferases needed to drive the synthesis of hybrid and complex type N-glycans (i.e., b-1,2-N-acetylglucosaminyltransferases I and II, b-1,4-galactosyltransferase, a-2,3- and a-2,6-sialyltransferases). Recent developments, fuelled by availability of genomic sequences and by advances in relevant methodologies, have shed some light on the subject, with a few unexpected twists. The identification of a transmembrane/Golgi hexosaminidase, an enzyme which removes a non-reducing N-acetylglucosamine residue during N-glycan biosynthesis, has demonstrated that the synthesis of complex-type N-glycans is actively and deliberately being prevented in insects. On the other hand, the characterisation of an active a-2,6-sialyltransferase in Drosophila, combined with the occurrence of sialylated N-glycan structures as detected in a detailed analysis of Drosophila embryos, has clearly shown that insects can, and need to, synthesise low levels of these structures. The current understanding of the insect N-glycan biosynthetic pathways taking place in Golgi apparatus and trans-Golgi network are elaborated and discussed

Aberrant glycosylation of Igg heavy chain in multiple myeloma

Although the majority of eukaryotic proteins are glycosylated, there is a dearth of knowledge regarding protein sugar moieties and their changes in disease. Most multiple myeloma cases are characterized by production of monoclonal immunoglobulins (Ig). We studied galactosylation and sialylation of IgG heavy chains in 16 patients with IgG myeloma using lectin blotting and densitometry. In comparison to age and sex matched controls, galactosylation was reduced in multiple myeloma (median 317 vs. 362, range 153-410 vs. 309-447 relative units, p = 0.015, Student's t-test). Sialylation was stage dependent; samples from patients with stage IIA had lowest amounts of sialic acid, IIIA intermediate and IIIB highest (142.6 vs. 185.9 vs. 248.5 relative units, correlation coefficient r = 0.55). Both galactosylation and sialylation levels were independent of age, sex, treatment type, response to treatment, disease duration and IgG and b2 microglobulin concentration. These data indicate that multiple myeloma is characterized by aberrant immunoglobulin glycosylation

Definition of immunogenic carbohydrate epitopes.

Carbohydrates are known as sources of immunological cross-reactivity of allergenic significance. In celery and in cypress pollen, the major allergens Api g 5 and Cup a 1 are recognised by antisera raised against anti-horseradish peroxidase and by patients' IgE which apparently bind carbohydrate epitopes; mass spectrometric analysis of the tryptic peptides and of their N-glycans showed the presence of oligosaccharides carrying both xylose and core α1,3-fucose residues. Core α1,3-fucose residues are also a feature of invertebrates: genetic and biochemical studies on the fruitfly Drosophila melanogaster, the parasitic trematode Schistosoma mansoni and the nematode worm Caenorhabditis elegans indicate that these organisms possess core α1,3-fucosyltransferases. Various experiments have shown that fucosyltransferases from both fly and worm are responsible in vivo and in vitro for the synthesis of N-glycans which cross-react with anti-horseradish peroxidase; thus, we can consider these enzymes as useful tools in generating standard compounds for testing cross-reactive carbohydrate epitopes of allergenic interest