Neurons in a variety of molluscs react to antibodies raised against the VD1/RPD2 α-neuropeptide of the pond snail Lymnaea stagnalis

The VD₁ and RPD₂ neurons of Lymnaea stagnalis innervate other central neurons, certain skin areas, the pneumostome area, and the auricle of the heart. Recently, a set of four (, , , ) neuropeptides produced by these giant neurons and by certain other central neurons has been characterized. Although alternative splicing of the preprohormone of these neurons yields at least 10 different neuropeptides, an affinity-purified antiserum directed against a domain common to all neuropeptides has previously been shown to be highly selective in staining VD₁, RPD₂ and other neurons that produce the preprohormone. Since the gene encoding the neuropeptides is structurally similar to that expressed in R15 of the marine opisthobranch Aplysia californica, we have used the affinity purified antiserum as a marker for VD₁/RPD₂-related systems in other molluscs. Immunopositive neurons and fibers are observed in the central nervous systems of all species studied (Achatina fulica, Anodonta sp., Aplysia brasiliana, A. californica, Bulinus truncatus, Cepea sp., Eobania vermiculata, Helix aspersa, H. pomatia, Limax maximus, Mytilus edulis, Nassarius reticulatus, Viviparus viviparus). Several medium-sized and small neurons and 1–4 giant neurons are found in the pulmonates and opisthobranchs. The giant neurons in pulmonates have locations in the subesophageal ganglion, axonal branching patterns, and terminal arborizations in the auricle of the heart; all these characteristics are similar to those of VD₁ and RPD₂. Double-labelling (Lucifer yellow injection, immunocytochemistry) confirms that the two giant neurons in Helix pomatia are Br and Br. The immunoreactive cells in A. fulica appear to include the VIN and PON neurons. The antiserum also stains cells that appear to be the R15 neurons in two Aplysia species. The small and medium-sized neurons are distributed widely over the central ganglia of opisthobranchs and pulmonates. In prosobranchs and bivalves, small neurons are found in the cerebral and abdominal ganglia. No evidence has been found for innervation of the heart in these latter groups but in M. edulis, immunoreactive terminals can be observed in the gill. The results suggest the evolutionary conservation of immunoreactive peptides and the neurons that produce them, and thus support and extend previous hypotheses regarding the homology of certain giant neurons across molluscan species.     

Inheritance of alleles for Cgy1 and Gy4 storage protein genes in soybean

Summary A cultivar lacking the glycinin subunit A₅A₄B₃ (Raiden) was crossed with one lacking the -subunit of -conglycinin (Keburi). Analysis of F₂ and F₃ progeny indicated that the missing bands of the A₅A₄B₃ and the -subunit were each controlled by a recessive allele of two independently segregating genes. Gene symbols Gy ₄/gy ₄ and Cgy ₁/cgy ₁ were proposed for the genes which confer the presence or absence of the glycinin and conglycinin subunits, respectively.Cooperative research of USDA-ARS and the Indiana Agric. Exp. Stn., Purdue Univ., West Lafayette, IN 47907, USA. Indiana Agric. Exp. Stn. Journal Article 9675. Financial support from the American Soybean Association Research Foundation is gratefully acknowledged     

Catecholamine receptor in the seawater eel intestine

Dose-response relationships of catecholamines on seawater eel intestinal ion transport were obtained; the potency order being (-)adrenalin>(-)noradrenalin=clonidine>(±)noradrenalin (racemic form of noradrenalin)>(-)phenylephrine>dopamine>(±)isoproterenol, indicating that ₂ are more potent than ₁- or -agonists. In addition, the effects of adrenalin were completely blocked by yohimbine (₂-antagonists) but not by prazosin (₁-antagonists) or propranolol (-antagonist). These results indicate the existence of an ₂-receptor in the seawater eel intestine. Adrenalin may activate the ₂-receptor physiologically, since adrenalin is the most potent stimulant and is the predominant catecholamine in American eel plasma (Hathaway and Epple 1989). Presumably ion and water absorption across the seawater eel intestine will be maintained by adrenalin. From the structure and the action of various agents used in the present study, structure-activity relationships of catecholamines are considered: hydroxyl groups on the benzene ring (catechol) seem to be essential for the ₂-action in the seawater eel intestine and the presence of OH and CH₃ on -carbon and amide, respectively, seems to potentiate the ₂-action.Abbreviations ACh acetylcholine - AD adrenalin - CONH 2-cyclooctyl-2-hydroxyethylamine; n-methyltransferase - DA dopamine - 5-HT serotonin - IBMX 3-isobutyl-1-methylxanthine - I _sc short-circuit current - MCh methacholine - NA noradrenalin - PD transepithelial potential difference - PNMT phenylethanolamine N-methyltransferase - R _t tissue resistance     

Expression of α1-adrenergic receptor subtypes in heart cell culture

Three ₁AR subtypes have been cloned so far and are designated as _1a, _1b, and _1d. Organspecific distribution pattern and subtype-specific effects are known but not fully understood. To address a cell-type specific expression pattern in the heart we investigated expression pattern of ₁AR subtypes on RNA and proteinlevel in heart tissue, cultured cardiomyocytes and nonmyocytes of the rat. Each ₁ARsubtype mRNA was present in neonatal and adult rat heart culture but the relative distribution pattern was significantly different. While the _1aAR subtype is preferentially expressed in adult cardiomyocytes, the _1bAR subtype was preferentially expressed in the nonmyocyte cell fraction. The RTPCR results were confirmed by Westernblotting (_1b) and immunocytochemical studies. Incubation with an ₁agonist (phenylephrine) for 72 h led to a significant reduction of the _1bAR in neonatal heart cell culture on both mRNA and protein level. In contrast, incubation with an ₁antagonist (prazosin) induced a 1.6 fold upregulation of the _1aAR mRNA without significant effects on radioligand binding and functional assay. The results indicate a distribution pattern of the ₁AR subtype which is specific for cell type and ontogeny of the rat heart and may be regulated by adrenergic agents.     

Glycerol-, inositol-, and reducing end hexose-containing oligosaccharides in human urine

Ten previously unreported oligosaccharides have been purified from the urines of human subjects using a combination of gel filtration, ion exchange, and thin-layer chromatographies. Their structures were determined by direct probe mass spectrometry, methylation analysis, and proton NMR spectroscopy of the permethylated oligosaccharide alditols.On the basis of composition, the oligosaccharides could be divided into three groups. Five oligosaccharides containing glycerol were characterized as glucosyl1-1glycerol; glucosyl1-1glycerol; galactosyl1-1glycerol; glucosyl-1-1(fucosyl-1-2)glycerol and/or fucosyl-1-1(glucosyl-1-2)glycerol; and glucosyl-1-1(galactosyl-1-2)glycerol or galactosyl-1-1(glucosyl-1-2)glycerol. Four inositol-containing oligosaccharides were characterized as galactosyl1 (fucosyl1)inositol,N-acetylgalactosaminyl1 (fucosyl1)inositol, fucosyl1-2galactosyl1 (N-acetylgalactosaminyl1)inositol and fucosyl1-2galactosyl1-4-N-acetylglucosaminyl1(N-acetylgalactosaminyl1)inositol. Finally, galactosyl1-3(fucosyl1-2)galactosyl1-6galactosyl1-4(fucosyl1-3)glucose, an oligosaccharide with glucose at its reducing end, was tentatively identified. The significance and possible origins of the carbohydrate structures are discussed.     

Variability in the 11S globulin fraction of seed storage proteins ofHelianthus (Asteraceae)

The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (₁₁ and ₂₂). The subunit corresponding to the ₁₁ pair is present inH. petiolaris and in the three populations ofH. annuus studied. The _2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific _2a2 and ₄₄ pairs andH. annuus a specific ₃₃ pair. InH. argophyllus _{11 33} or ₄₄ are never observed but are replaced by ₁₃ and ₃₁ pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins.     

Pseudo vitamin B12 or 5-hydroxybenzimidazolyl-cobamide are the corrinoids found in methanogenic bacteria

Thirteen species of methanogenic bacteria were analyzed for corrinoids. Pseudo vitamin B₁₂ (Co-[-(7-adenyl)]-cobamide) was the predominant cobamide of methanococcales and Methanoplanus. All other methanogens contained factor III (Co-[-(5-hydroxybenzimidazolyl)]-cobamide). Vitamin B₁₂ (Co-[-(5,6-dimethylbenzimidazolyl)]-cobamide) was not detected in any of these archaebacteria. Their cobamide content was 100 to 1400 nmol per gram cell dry weight, indicating that abundant cobamides are essential for methanogens.     

Ganglioside lactones:1H-NMR determination of the inner ester position of GD1b-ganglioside lactone naturally occurring in human brain or produced by chemical synthesis

The complete definition of the chemical structure of G_D1b-ganglioside (G_D1b) lactone isolated from human brain has been given by means of spectrometric and spectroscopic analyses. G_D1h lactone contains a single ester linkage involving the external sialic acid carboxyl group and the C-9 hydroxyl group of the internal sialic acid unit. A synthetic lactone of G_D1b prepared treating G_D1b with glacial acetic acid characterized in the same way showed an identical chemical structure.Abbreviations: Ganglioside nomenclature is according to Svennerholm [16] and the IUPAC-IUB Recommendations [17] G_M1 G_M1-ganglioside, II³NeuAc-GgOse₄Cer, Gal1-3GalNac1-4[NeuAc2-3]Gal1-4Glc1-1Cer - G_D1b G_D1b-ganglioside, II³(NeuAc)₂GgOse₄Cer, Gal1-3GalNAc1-4[NeuAc2-8NeuAc2-3]Gal1-4Glc1-1Cer - G_D1b lactone G_D1b-L, Gal1-3GalNAc1-4[NeuAc(1-9)2-8NeuAc2-3]Gal1-4Glc1-1Cer - Cer ceramide - FAB-MS fast atom bombardment-mass spectrometry - ¹H-NMR proteon nuclear magnetic resonance - 1D-NMR one dimensional NMR - 2D-COSY two dimensional correlated spectroscopy - DMSO-d₆ deuterated dimethylsulfoxide     

Differential subcellular localization of ACTH and α-MSH in corticotropes of the rat anterior pituitary

Summary Specific antisera to -melanotropin (-MSH) and corticotropin (ACTH 1-39) were used to obtain immunocytochemical evidence for the differential localization of -MSH and ACTH in the secretory granules of corticotropes of rat anterior pituitary. The specificity of the antisera was established by binding ¹³¹I-labeled -MSH and ACTH 1-39 to their respective antisera. Double-labeling immunocytochemistry (for -MSH, ferritin; for ACTH, colloidal gold) was performed. Some secretory granules were labeled with ferritin particles (-MSH), whereas others contained gold particles (ACTH). Only a few granules showed both ACTH and -MSH. In typical corticotropes (stellate in form with a small number of secretory granules aligned along the cell periphery) only some of the secretory granules that were labeled with anti-ACTH serum were also immunoreactive to anti--MSH. In atypical corticotropes (polygonal in shape and containing a large number of secretory granules) almost all of the immunoreactive ACTH secretory granules were also positive to anti--MSH serum. An intermediate type of corticotrope was observed containing a small number of secretory granules, almost all of which were labeled with anti--MSH. Thus, rat anterior pituitary corticotropes may be classified into three types according to the distribution and content of -MSH. The light-microscopic immuncytochemistry provided similar results.     

Isolation and partial sequence of goat spleen prothymosin α

Goat prothymosin , a highly acidic polypeptide of pl 3.5, 109 amino acid residues, has been isolated from lymphoid and non-lymphoid tissues of young female goats. Unlike rat, murine and porcine prothymosins , goat prothymosin appears at a higher concentration in the spleen compared with the thymus. The sequence of segments of the polypeptide involving known mutations has been determined, by automatic sequencing of its tryptic peptide fragments. The acidic amino acid-rich segment in the middle of the molecule, including residues 49–83, has not been sequenced. Goat prothymosin closely resembles bovine prothymosin , with only one substitution, proline for alanine at position 85. It also resembles human prothymosin , with only three substitutions. It differs more significantly from rat and murine prothymosins , by two deletions and three substitutions. The results show the highly conserved nature of the molecule, with substitutions at given positions only.Abbreviations ProT Prothymosin - T₁ Thymosin ₁ - MLR Mixed Lymphocyte Response - HPLC High Performance Liquid Chromatography - RIA Radioimmunoassay - B Aspartic acid or Asparagine - Z Glutamic acid or Glutamine     

Nucleotide sequence of a DNA region comprising the gene for elongation factor 1α (EF-1α) from the ultrathermophilic archaeotePyrococcus woesei: Phylogenetic implications

Summary The gene encoding elongation factor 1 (EF-1, 1290 bp) of the ultrathermophilic, sulfur-reducing archaeotePyrococcus woesei was localized within aBglII fragment of chromosomal DNA. Sequence analysis showed that the EF-1 gene is the upstream unit of a three-gene cluster comprising the genes for ribosomal protein S10 (306 bp) and transfer RNA_ser (GGA). The three genes follow each other immediately in the order EF-1·S10·tRNA_ser after a putative promoter located 55 bp upstream of the EF-1 gene. Alignment of the derived EF-1 sequence with the corresponding sequences from Eukarya, Bacteria/organelles, and with available archaeal sequences (Sulfolobus, Thermococcus, Methanococcus, Halobacterium) showed thatPyrococcus EF-1 is highly homologous (89% identity) toThermococcus celer EF-1, both being strikingly more similar to eukaryotic EF-1 than to bacterial EF-Tu. Unrooted dendrograms computed from aligned sequences by distance matrix and DNA parsimony methods, including evolutionary parsimony, showed the Archaea to be a monophyletic-holophyletic cluster closer to Eukarya than to Bacteria. Both distance matrix and DNA parsimony-although not evolutionary parsimony-support the partition of the known archaeal lineages between the kingdoms Crenarchaeota and Euryarchaeota, and the affiliation of thePyrococcus-Thermococcus lineage to the Euryarchaeota, of which it is the most primitive offspring. A closer relation ofPyrococcus to Euryarchaeota than to Crenarchaeota was also inferred from sequence analysis of S10 ribosomal proteins.     

Structures of asparagine linked oligosaccharides of immunoglobulins (IgY) isolated from egg-yolk of Japanese quail

Structures of the Asn linked oligosaccharides of quail egg-yolk immunoglobulin (IgY) were determined in this study. Asn linked oligosaccharides were cleaved from IgY by hydrazinolysis and labelled withp-aminobenzoic acid ethyl ester (ABEE) afterN-acetylation. The ABEE labelled oligosaccharides were then fractionated by a combination of Concanavalin A-agarose column chromatography and anion exchange, normal phase and reversed phase HPLC before their structures were determined by sequential exoglycosidase digestion, methylation analysis, HPLC, and 500 MHz¹H-NMR spectroscopy. Quail IgY contained only neutral oligosaccharides of the following categories: the glucosylated oligomannose type (0.6%, Glc1-3Glc1-3Man₉GlcNAc₂; 35.6%, Glc1-3Man_7–9GlcNAc₂). oligomannose type (15.0%, with the structure Man_5–9GlcNAc₂) and biantennary complex type with core structures of-Man1-3(-Man1-6)Man1-4GlcNAc1-4GlcNAc (9.9%),-Man1-3(GlcNAc1-4)(-Man1-6)Man1-4GlcNAc1-4GlcNAc (25.1%) and-Man1-3(GlcNAc1-4)(-Man1-6)Man1-4GlcNAc1-4(Fuc1-6)GlcNAc (11.4%). Although never found in mammalian proteins, glucosylated oligosaccharides (Glc₁Man_7–9GlcNAc₂) have been located previously in hen IgY.Abbreviations IgG, IgM, IgA, IgY immunoglobulin G, M, A and Y, respectively - ABEE p-aminobenzoic acid ethyl ester     

Modification of lignin by Geotrichum klebahnii

¹³C-NMR spectroscopic analysis indicates that the yeast-like species Geotrichum klebahnii is an efficient microorganism for lignin biodegradation. This strain modified beechwood lignin even if it was the only carbon source by C-C side chain cleavage, C-oxidations, aromatic ring cleavage and reductive reactions. The obtained results outline prospective application of G. klebahnii for biotechnological pre-treatment of lignocellulosic materials.     

Immunocytochemical evidence for intragranular processing of pro-opiomelanocortin in the melanotropic cells of the rabbit

Summary The immunogold technique, employing antisera with clear-cut specificities, was used to localise different processing stages of pro-opiomelanocortin (POMC) in rabbit melanotropic cells. While the antiserum against ₃-MSH labelled all the secretory granules including intrasaccular condensations in the Golgi apparatus, antisera against -MSH only labelled extra-Golgi secretory vesicles (SV). All extra-Golgi SV were likewise labelled with the three antisera against -MSH used, despite their different specificities for the desacetylated, N-acetylated or C-amidated forms of the peptide. The antibody against -endorphin also labelled the extra-Golgi SV, while only some SV were labelled with the antibody against -endorphin. These results correlate with biochemical data in favour of mainly — if not exclusively — intragranular processing of POMC. Except for ₃-MSH, the cleavage of which could coincide with Golgi packaging of secretory material, other post-translational modifications of the precursor seem to occur when SV are discharged outside the Golgi area. The cleavage of -endorphin appears to be a later step in POMC processing, occurring in some mature SV.     

Die Bedeutung der “feedback”-Hemmung der Threonin-Desaminase für die Synthese von Valin und Leucin

Zusammenfassung In Arthrobacter Stamm 23 führte die durch Mutation verursachte allosterische Unempfindlichkeit der Threonin-Desaminase zur dereprimierten Bildung der Enzyme im Isoleucin-Valin-Leucin-Biosyntheseweg. Derepression erfolgte auch, wenn Wildtypzellen in Gegenwart von -Ketobuttersäure inkubiert wurden. In beiden Fällen wurde Isoleucin überproduziert und ins Kulturmedium ausgeschieden. Wie aus Wachstumsexperimenten hervorging, verursachte der Überschuß an -Ketobuttersäure im Medium primär einen Valin- und Leucin-Mangel, der zu einer vorübergehenden Wachstumshemmung führte. Durch die dereprimierte Bildung der Enzyme im Isoleucin-Valin-Biosyntheseweg konnte die Wachstumshemmung überwunden werden.Der vorübergehende Hemmeffekt der -Ketobuttersäure ließ sich auf eine Konkurrenz der Substrate am ersten gemeinsamen Enzym im Isoleucin-Valin-Biosyntheseweg, der Acetohydroxysäure-Synthase, zurückführen. Wegen des niedrigen K _m-Wertes für -Ketobuttersäure wird dieses Substrat vom Enzym bevorzugt umgesetzt. Durch gaschromatographische Bestimmungen der Acetoin- und Acetyläthylcarbinol-Bildung in Enzymtests mit variierten Substrat-Konzentrationen konnte nachgewiesen werden, daß relativ geringe Konzentrationen an -Ketobuttersäure genügen, um die -Acetolacetat-Bildung vollständig zu unterdrücken. Diese Ergebnisse erklären die durch -Ketobuttersäure verursachte vorübergehende Wachstumshemmung bei Bakterien.

---

The effect of the feedback inhibition of threonine deaminase on valine-leucine biosynthesis

In Arthrobacter strain 23 the allosteric insensitivity of threonin deaminase caused by mutation resulted in derepressed formation of the enzymes of the isoleucine-valine-leucine pathway. Derepression was also observed, when wild type cells were incubated in the presence of -oxobutyrate. In both cases isoleucine was overproduced and excreted. As growth experiments indicated the excess of -oxobutyrate in the medium caused endogenous valine and leucine deficiency and a transient inhibition of growth. Derepressed formation of the isoleucinevaline biosynthetic enzymes resulted in relief of growth inhibition.The transient inhibitory effect of -oxobutyrate has been traced back to substrate competition at the first enzyme common to the isoleucine and valine pathway, acetohydroxy acid synthase. Due to the low K _m of the enzyme for -oxobutyrate this substrate is preferentially converted. As proven by gaschromatographical measurements of acetoin and acetylethyl carbinol produced in enzyme (acetohydroxy acid synthase) assays with varied substrate concentrations, relatively low concentrations of -oxobutyrate are able to suppress the formation of -acetolactate completely. These results explain the transient inhibitory effect of -oxobutyrate on the growth of bacteria.

---

Abkürzungen -KBS -Ketobuttersäure - FAD Flavin-adenin-dinucleotid - AHS Acetohydroxysäure - IPM Isopropylmalat - TPP Thiaminpyrophosphat     

Structural Peculiarities of Na+,K+-ATPase Isozymes from the Calf Brain

Functionally active preparations of Na⁺,K⁺-ATPase isozymes from calf brain that contain catalytic subunits of three types (1, 2, and 3) were obtained using two approaches: a selective removal of contaminating proteins by the Jorgensen method and a selective solubilization of the enzyme with subsequent reconstitution of their membrane structure by the Esmann method. The ouabain inhibition constants were determined for the isozymes. The real isozyme composition of the Na⁺ pump from the grey matter containing glial cells and the brain stem containing neurons was determined. The plasma membranes of glial cells were shown to contain mainly Na⁺,K⁺-ATPase of the 11 type and minor amounts of isozymes of the 22(1) and the 31(2) type. The axolemma contains 21 and 31 isozymes. A carbohydrate analysis indicated that 11 enzyme preparations from the brain grey matter substantially differ from the renal enzymes of the same composition in the glycosylation of the 1 isoform. An enhanced sensitivity of the 3 catalytic subunit of Na⁺,K⁺-ATPase from neurons to endogenous proteolysis was found. A point of specific proteolysis in the amino acid sequence PNDNR⁴⁹² Y⁴⁹³ was localized (residue numbering is that of the human 3 subunit). This sequence corresponds to one of the regions of the greatest variability in 1-, 2-, 3-, and 4-subunits, but at the same time, it is characteristic of the 3 isoforms of various species. The presence of the 3 isoform of tubulin (cytoskeletal protein) was found for the first time in the high-molecular-mass Na⁺,K⁺-ATPase 31 isozyme complex isolated from the axolemma of brain stem neurons, and its binding to the 3 catalytic subunit was shown.     

A new non-equilibrium enzyme linked immunosorbent assay for a glycogen-derived urinary tetrasaccharide

The tetrasaccharide, Glc1-6Glc1-4Glc1-4Glc, denoted (Glc)₄, is a limit dextrin formed by amylolytic degradation of glycogen. In order to evaluate the possible clinical importance of (Glc)₄ excretion as an indicator of certain physiological and pathological conditions, we have developed a new rapid and inexpensive immunoassay using a monoclonal antibody raised against (Glc)₄ glycosidically-linked to a carrier protein. As the antibody is highly specific, it can be used to measure native (Glc)₄ directly, without the chemical reduction step required in previous methods. A new type of non-equilibrium ELISA inhibition test was developed based on the capacity of free (Glc)₄ to decrease initial rates of antibody binding to (Glc)₄-coated microtiter wells. The method is highly reproducible and is as sensitive and accurate as the gas chromatography method or radioimmunoassay used previously.Abbreviations (Glc)₄ Glc1-6Glc1-4Glc1-4Glc - KLH keyhole limpet hemacyanin - BSA bovine serum albumin - PEG polyethylene glycol     

Structural analysis of the carbohydrate moieties of α-l-fucosidase from human liver

Acid -l-fucosidase (EC 3.2.1.51) was obtained from human liver and purified to homogeneity. The enzyme consists of four subunits; each of these has a molecular mass of 50 kD_a and bears oneN-linked carbohydrate chain. The structures of these chains were studied at the glycopeptide level by methylation analysis and 500-MHz¹H-NMR spectroscopy. Oligomannoside-type chains andN-acetyllactosamine-type chains are present in an approximate ratio of 31. While the oligomannoside-type chains show some heterogeneity in size (Man_5–8GlcNAc₂), theN-acetyllactosaminetype chains are exclusively bi-(2–6)-sialyl, bi-antennary in their structure.These observations on the carbohydrate moieties of -l-fucosidase substantiate our hypothesis [Overdijket al. (1986) Glycoconjugate J 3:339–50] with respect to the relationship between the oligosaccharide structure of lysosomal enzymes and their residual intracellular activity in I-cell disease. For the series of enzymes examined so far, namely, -N-acetylhexosaminidase, -l-fucosidase and -galactosidase, the relative amount ofN-acetyllactosamine-type carbohydrate increases, while the residual intracellular activity in I-cell disease tissue decreases in this order. The system which is responsible for preferentially retaining hydrolases with (non-phosphorylated) oligomannoside-type chains both in I-cells and in normal cells has yet to be identified.     

Carbohydrates of influenza virus. Structure of the oligosaccharides linked to asparagines 406 and 478 in the hemagglutinin of fowl plague virus,strain dutch

Fowl plague virus, strain Dutch, was metabolically labeled withd-[2-³H]mannose, or withd-[6-³H]glucosamine, and the small subunit (HA₂; 0.8 mg in total) of the viral hemagglutinin was isolated by preparative sodium dodecylsulfate-polyacrylamide gel electrophoresis. After proteolytic digestion, the radioactive oligosaccharides were sequentially liberated from the glycopeptides by treatment with different endo--N-acetylglucosaminidases and with peptide:N-glycosidase or, finally, by hydrazinolysis. In this manner, four groups of glycans could be obtained by consecutive gel filtrations and were subfractionated by HPLC. The structures of the individual oligosaccharides were analyzed by micromethylation, by acetolysis or by digestion with exoglycosidases. The major species amongst the high mannose glycans at Ans-406 of the viral glycopolypeptide were found to be Man1-2Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNac1-4GlcNAc and Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNAc1-4GlcNAc, while the complex glycans at Asn-478 are predominantly GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc (lacking, in part, one of the outerN-acetylglucosamine residues) and GlcNAc1-2Man1-3(Gal1-4GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc.Abbreviation BSA bovine serum albumin - endo D (F,H) endo--N-acetyl-d-glucosaminidase D (F,H) - HA hemagglutinin (HA₁, large subunit of HA - HA₂ small subunit - FPV fowl plague virus - PNGase F peptide:N-glycosidase F - SDS sodium dodecylsulfate