Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In our previous study, a drastic change in terminal saccharides of glycoconjugates of the hamster zona pellucida associated with oocyte maturation was observed using light microscopic methods of lectin cytochemistry. To understand the mechanism of this change, in the present study, the correlation between the cytochemical appearance of saccharide residues in the zona pellucida and nuclear maturation was examined. Immature hamsters were treated with PMSG and hCG to induce follicular development and ovulation. The animals were euthanized 0 to 26 hrs. after the injection of PMSG or 0,1,2,3,4,5,7,9 or 11 hrs. after the injection of hCG, and ovaries were dissected out, fixed, paraffin embedded and sectioned serially. Every other paraffin section was stained with hematoxylin to observe the status of nuclei and to classify follicular growth and only the fully developed preovulatory follicles were examined in experiments. The peroxidase-labelled lectin-diaminobenzidine procedure was applied to sections. The lectins employed were WGA, SBA, MPA, UEA-I, LotusA and AAA. Germinal vesicle breakdown was observed within 3 hrs. after the administration of hCG. A positive reaction of WGA, SBA or MPA for zonae pellucidae in the fully developed preovulatory follicles appeared 1 hr. after hCG injection, and remained so for the next 10 hrs. UEA-I, Lotus A and AAA reactions were negative for all of the zonae pellucidae observed. The data indicate that the synthesis of saccharide residues such as GlcNAc and GalNAc forming zona components in the follicles is not triggered by germinal vesicle breakdown.
Cell Mol Biol 1991
PMID:Appearance of lectin binding affinity to the zona pellucida during hamster oocyte maturation. 174 97

The surface membrane-associated 3'-nucleotidase/nuclease (3'-N'ase) of Leishmania donovani has been purified from detergent extracted promastigotes by anion and cation exchange, lectin affinity and gel filtration chromatography. SDS-PAGE analysis of the purified enzyme preparation revealed a 43-kDa polypeptide as well as faster migrating bands. These bands co-migrated, following both one- and two-dimensional electrophoretic analyses, with enzyme activity as determined by an in situ 3'-nucleotidase gel activity assay. It is suggested that the lower molecular weight species arise during purification as a result of proteolytic cleavage of the intact 43-kDa enzyme. The 3'-N'ase exhibited a pI of 5.4, as revealed by 2-dimensional gel electrophoresis. The glycoprotein nature of the 3'-N'ase was suggested by its binding to concanavalin A and by its electrophoretic shift following incubation with N-glycanaseR. In nucleotidase and nuclease assays, the 3'-N'ase was most active with 3'-AMP and poly(A), respectively. Both nucleotidase and nuclease activities exhibited broad pH optima with peaks at 8.5 and 7.5, respectively. At pH 8.5 nucleotidase activity was inhibited by EDTA, Zn2+ and thiols, but was insensitive to tartrate, molybdate and fluoride ions, commonly used inhibitors of phosphatases. The properties of the leishmanial 3'-N'ase was similar to the 3'-N'ase purified from purine-starved Crithidia luciliae, a related trypanosomatid protozoan, and to group of nucleases from fungi and germinating plant seedlings.
Mol Biochem Parasitol 1991 Jul
PMID:Purification and characterization of the 3'-nucleotidase/nuclease from promastigotes of Leishmania donovani. 185 79

A gene encoding the preproprotein of the pea (Pisum sativum) lectin was expressed in transgenic potato plants using a cauliflower mosaic virus (CaMV) 35S promoter or a tobacco ribulose bisphosphate carboxylase small subunit (ssRubisco) promoter. Presence of the pea lectin to levels greater than 1% of total soluble leaf protein was detected by radioimmunoassay (RIA). The pattern of expression derived from the two promoters was established using both RIA and a squash-blot immunolocalisation technique. Western blotting demonstrated that the preproprotein was correctly processed, generating alpha and beta subunits that assembled to give an isolectin form observed in pea seeds and roots. It was also found that the haemagglutination activity and specificity of pea lectin synthesised in transgenic potato leaves was comparable to purified lectin from pea cotyledons.
Plant Mol Biol 1991 Jul
PMID:Pea lectin is correctly processed, stable and active in leaves of transgenic potato plants. 186 25

A comparative study of gelonin and A-chains of ricin, mistletoe lectin I and diphtheria toxin was undertaken. The effect of pH was studied on: a) the conformation of the proteins under study using intrinsic fluorescence; b) interaction of these proteins with ricin B-chain using gel-filtration. Structural stability of the proteins was assessed according to denaturing action of guanidine hydrochloride and temperature, and localization of tryptophan residues was determined using fluorescence quenching by I-, Cs+ and acrylamide. All investigated proteins were shown to undergo the conformational changes when a environment became acidic. In comparison with an intact protein--gelonin, the A-chains of ricin, a mistletoe lectin and a diphtheria toxin are less stable. At pH less than 5.0 tryptophan residues became more accessible to quencher and a positive charge of the surrounding area increases (in the case of gelonin it is negatively charged). No reliable interaction of a ricin B-chain with both gelonin and A-chain of diphtheria toxin was observed. The interaction of a ricin B-chain with a A-chain of mistletoe lectin I is weaker than that with ricin A-chain and is practically pH-independent.
Mol Biol (Mosk)
PMID:[Features of the structure of catalytic subunits of toxins, inhibiting protein synthesis. I. The effect of pH and interaction with the B-chain of ricin]. 188 95

In the last decade, research in our laboratories has focused on the effects of deafferentation of the mammalian chemosensory vomeronasal organ (VNX). Many different assays have been conducted and the results of some are briefly reviewed in this contribution, including the effects of VNX on neuroanatomical assessments using histochemistry (lectin binding) and immunohistochemistry (LHRH), male mouse and prairie vole ultrasonic vocalizations and hormone surges in response to cues from females, male mouse courtship and sexual behavior, territorial marking and inter-male aggression, the production of a puberty-altering substance found in mice, activation of reproduction in female voles (who generally do not exhibit estrous cycles) and maternal behaviors by female mice, including aggression directed toward intruder males. In some instances, the otherwise detrimental effects of VNX can be overcome by experience prior to deafferentation, especially in assays that are dependent upon expressions of behavior. In other situations, experience may have little impact on amelioration of the effects of VNX. The essential conclusions of this work focus our attention on reproductive physiology and behavior and a role for the vomeronasal organ in the perception of pheromones that modulate these functions.
J Steroid Biochem Mol Biol 1991 Oct
PMID:Consequences of removing the vomeronasal organ. 189 95

In the course of this study we found that in Mytilus galloprovincialis eggs long filamentous protrusions never described before, which we have termed "vitelline coat spikes," could be clearly detected using the lectin from Dolichos biflorus, which recognizes the GalNAc residues. The spikes could be also observed by transmission electron microscope but only in some fortuitous sections could their origin in the vitelline coat be clearly observed. The spikes were also clearly visible using the scanning electron microscope. Observations of the sperm-egg interaction very few seconds after insemination or using fixed eggs suggested that the spikes could play a role in a primary binding to the unreacted sperm. Experiments have been done to test the effect of GalNAc on the sperm-egg binding and on the fertilization process which seem to confirm this hypothesis.
Mol Reprod Dev 1991 Feb
PMID:The vitelline coat spikes: a new peculiar structure of Mytilus galloprovincialis eggs with a role in sperm-egg interaction. 190 Sep 92

In the face of constant exposure to inhaled antigens, precise local regulation of immune responses in the pulmonary alveolar space is essential to achieve a delicate balance between host defense and excessive immune responses that are incompatible with the primary physiologic function of the lung. We postulated that the cells of the alveolar epithelium may have an immunoregulatory role in the lung. Therefore, we have examined the effects of primary cultures of rat type II alveolar epithelial cells on lymphocyte proliferation and on the expression of a number of markers of T-cell activation. Monolayers of alveolar epithelial cells suppressed proliferation and DNA synthesis by concanavalin A-stimulated rat splenocytes. Suppression of [3H]thymidine incorporation was independent of the dose of mitogen and was also apparent when lymphocytes were stimulated with phorbol esters and calcium ionophore, suggesting that the effect was independent of cell surface binding of the lectin. Suppression was reversed 48 h after lectin-stimulated splenocytes were removed from co-culture with alveolar epithelial cells. Despite inhibition of lymphocyte proliferation, other markers of T-cell activation were induced normally in lymphocytes cultured with alveolar epithelial cells. Culture with alveolar epithelial cells did not inhibit the the production of interleukin-2 by stimulated lymphocytes. Furthermore, by fluorescence-activated cell sorter analysis, equal proportions of stimulated lymphocytes in culture alone or with alveolar epithelial cell monolayers were induced to express receptors for interleukin-2 and for transferrin.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1991 Sep
PMID:Alveolar epithelial cells block lymphocyte proliferation in vitro without inhibiting activation. 191 Aug 8

Effect of Erythropoietin (Ep) on the interaction of Concanavalin A (Con A) with rat erythrocytes was studied using 125I-labelled Con A. Binding of Con A to erythrocytes was dependent on time and cell concentration. Starvation caused an elevation of the lectin binding capacity of red cells which again came down towards the normal level on Ep administration to starved rats. Binding of Con A to erythrocytes decreased linearly with increasing concentration of Ep. Specificity of binding was confirmed by inhibition studies with alpha-methyl-D-mannopyranoside (Me Man) Cells from the starved rats compared to those from normal and Ep treated animals were less prone to inhibition by this sugar analog. Positive cooperative binding of Con A to rat erythrocyte was observed at low concentration of Con A but was absent at higher lectin concentrations. Starvation caused an increase in the number of binding sites per cell which returned to normal level after Ep treatment. Under identical conditions, binding affinities were not much changed in these cells. Cells from the starved animals were more susceptible to agglutination compared to those from normal and Ep-treated rats. Microviscosity and cholesterol/phospholipid ratio of red cell membrane decreased in the starved animals which retraced its way back towards the normal level after Ep treatment.
Mol Cell Biochem 1991 Aug 14
PMID:Effect of erythropoietin on the interaction of concanavalin A with rat erythrocytes. 192 16

Pulmonary infiltrating lymphocytes (PIL) isolated directly from human lung were examined for their surface immune phenotype by monoclonal antibody staining and cytofluorimetry. In order to purify PIL, resected lungs were enzymatically digested with collagenase and DNase and subjected to density centrifugation and nylon-wool column separation. In some cases, CD4+ lymphocytes were further purified with alpha CD8 and complement. The majority of pulmonary lymphocytes were CD2+ (87 +/- 1%) and CD3+ (73 +/- 4%). Virtually all of the CD3+ PIL were Ti alpha beta+. Greater than 90% of both CD4+ or CD8+ PIL were CD45RO+ and CD45RA-, consistent with prior antigen sensitization in vivo. A subset of CD4+ PIL (34 +/- 4%) expressed Leu8, the human congener of the murine MEL-14 lymphocyte homing receptor, whereas most homologous CD4+ peripheral blood lymphocytes were Leu8+ (75 +/- 8; P less than 0.01). HLA-DR surface antigens were expressed by 45 +/- 5% of CD4+ PIL versus 9 +/- 1% of CD4+ peripheral blood lymphocytes (P less than 0.001). There was no significant difference in the percentage of low-affinity interleukin-2 (IL-2) receptor-positive CD4+ lymphocytes in lung and blood (9 +/- 3% versus 13 +/- 2%). Analysis of the DNA synthetic cell cycle showed that approximately 5% of blood CD4+ lymphocytes and approximately 25% of CD4+ PIL were in S/G2/M. Compared to homologous blood T cells, purified PIL displayed enhanced proliferative responses to IL-2 and diminished responses to the lectin phytohemagglutinin. Lectin-stimulated PIL showed greater secretion of interferon-gamma and IL-2 than did blood lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1991 Nov
PMID:Most human pulmonary infiltrating lymphocytes display the surface immune phenotype and functional responses of sensitized T cells. 193 Oct 75

Four new crystal forms of the anti-T lectin from jackfruit (Artocarpus integrifolia) have been prepared and characterized. Three of them, two monoclinic (P21, a = 59.4 A, b = 83.3 A, c = 63.5 A, beta = 107.7 degrees; C2, a = 106.1 A, b = 53.9 A, c = 128.0 A, beta = 95.0 A) and one orthorhombic (C222(1), a = 98.1 A, b = 67.3 A, c = 95.1 A) were grown with 2-methylpentan-2,4-diol (MPD) as the precipitant while the fourth, an hexagonal form (P6(1)22, a = b = 129.6 A, c = 157.9 A), was obtained in the presence of methyl-alpha-D-galactopyranoside with polyethylene glycol 4000 as the precipitant. The reported relative molecular mass (Mr) of the lectin was found to be inconsistent with the solvent content of the crystals estimated using measured densities. The Mr was redetermined using size-exclusion chromatography in the presence of methyl-alpha-D-galactopyranoside and Ferguson-plot analysis of mobilities in polyacrylamide gel electrophoresis. The redetermined Mr (66,000) is consistent with the measured crystal densities. The orthorhombic and the hexagonal forms, which have one half molecule and one molecule, respectively, in the asymmetric unit, are suitable for high-resolution X-ray analysis.
J Mol Biol 1991 Oct 05
PMID:Preparation and X-ray characterization of four new crystal forms of jacalin, a lectin from Artocarpus integrifolia. 194 30


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