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At least 343 records · Page 19Linked to original sources

PubMed1988

AIDS: no association with the genetic systems GC (D-binding protein), ORM (orosomucoid = alpha-1-acid glycoprotein), and A2HS (alpha-2-HS-glycoprotein).

In a sample of 97 HIV-1 seropositive persons which comprised 34 patients with AIDS, 30 patients with persistent generalized lymphadenopathy or with AIDS related complex and 33 persons who were without symptoms and called "healthy", three genetic marker systems were examined: 1) GC, the group-specific component of serum which is identical with the vitamin D binding protein (DBP) of serum, 2) ORM, the acute phase protein orosomucoid = alpha-1-acid glycoprotein of serum, and 3) A2HS, the alpha-2-AS glycoprotein of serum. The distribution of the genotypes and of the alleles in the sample of AIDS patients and of HIV-1/positive persons was not different from the distribution in control groups. An association between susceptibility and/or resistance for AIDS and these genetic marker systems was not observed.

Acquired Immunodeficiency Syndrome↗

PubMed1995

SLR3: a modified receptor kinase gene that has been adapted to encode a putative secreted glycoprotein similar to the S locus glycoprotein.

A new member of the S gene family, SLR3 (S-Locus Related 3), was identified in Brassica oleracea. This gene had a novel pattern of expression compared with previously described members of the family, being expressed in petals, sepals and vegetative apices, in addition to stigmas and anthers. Moreover, use of SLR3-derived probes in RNA blot and RACE-PCR (rapid amplification of cDNA ends-polymerase chain reaction) experiments has identified transcripts of genes closely related to SLR3 in leaves, cotyledons and, at high levels in developing anthers. SLR3 is not linked to the S locus but is linked to two or three closely related genes. Sequence analysis of the SLR3 gene indicates that it is derived from an ancestral receptor kinase gene that has been modified by a series of deletion events. As a result of these modifications, SLR3 is predicted to encode a secreted glycoprotein lacking both transmembrane and kinase domains. The putative SLR3 protein differs from the products of most other S gene family members in that several of the highly conserved cysteines have been lost. Within the S gene family, modification of receptor kinase genes by deletion may represent a general mechanism for the generation of genes encoding secreted glycoproteins.

Amino Acid Sequence↗

PubMed1996

SGP28, a novel matrix glycoprotein in specific granules of human neutrophils with similarity to a human testis-specific gene product and a rodent sperm-coating glycoprotein.

A novel 28 kDa glycoprotein was purified from exocytosed material from human neutrophils and its primary structure partially determined. Degenerate oligonucleotide primers were used to amplify cDNA clones from a human bone marrow cDNA library. The deduced 245 amino acid sequence of the 2124 bp full-length cDNA showed high degrees of similarity to the deduced sequences of human gene TPX-1 and of sperm-coating glycoprotein from rat and mouse. Subcellular fractionation of human neutrophils indicated that the protein is localized in specific granules. The protein was named SGP28 (specific granule protein of 28 kDa).

Amino Acid Sequence↗

PubMed1996

Analysis of glycoproteins, glycopeptides and glycoprotein-derived oligosaccharides by high-performance capillary electrophoresis.

Recent developments in the analysis of glycoproteins by high-performance capillary electrophoresis are reviewed, with emphasis on their carbohydrate chains. Glycoforms of glycoproteins were directly separated from each other by careful optimization of the analytical conditions. Glycopeptides in tyrptic digests were separated and the peptides carrying glycosylation sites were differentiated from others. Released oligosaccharide chains were separated from each other by direct or modified zone electrophoresis and directly detected by measuring the UV absorption at a low wavelength. Precolumn derivatization by various methods extended the utility of both the separation mode and detection technique. Dual mode analysis after derivatization permitted reliable identification and quantification without references.

Carbohydrate Sequence↗

PubMed1989

The human cytomegalovirus strain Towne glycoprotein H gene encodes glycoprotein p86.

The gene encoding the glycoprotein H (gH) homologue of CMV strain Towne was cloned, sequenced, and expressed. The predicted 742 amino acid gH protein had characteristics typical of a membrane glycoprotein including hydrophobic signal and transmembrane domains and six possible N-linked glycosylation sites. The CMV (Towne) gH gene had a 95% nucleotide identity and a 96.6% amino acid identity with the CMV (AD169) gH gene, as described by M. P. Cranage, G. L. Smith, S. E. Bell, H. Hart, C. Brown, A. T. Bankier, P. Tomlinson, B. G. Barrell, and T. C. Minson (1988, J. Virol. 62, 1416-1422). Transcriptional analysis of the gH gene revealed that the 2.9-kilobase (kb) gH transcript was not detected until late after CMV infection, indicating that the kinetics of gH expression were typical of the late class of CMV genes. The gH gene was expressed in COS cells using a vector in which transcription was driven by the SV40 early promoter. The expression of gH was detected by immunofluorescence using the virus neutralizing murine monoclonal antibody 1G6, which is specific for an 86-kilodalton (kDa) CMV virion membrane protein (p86). Amino acid sequence analysis of p86 tryptic peptides revealed sequence identity with peptides from the deduced gH amino acid sequence, confirming that the gH gene encodes p86. These results indicate that CMV gH can induce virus neutralizing antibodies and establishes gH as a candidate antigen for a subunit vaccine against CMV.

Amino Acid Sequence↗

PubMed1992

Open reading frames encoding a protein kinase, homolog of glycoprotein gX of pseudorabies virus, and a novel glycoprotein map within the unique short segment of equine herpesvirus type 1.

DNA sequence analysis of the unique short (Us) segment of the genome of equine herpesvirus type 1 Kentucky A strain (EHV-1) by our laboratory and strains Kentucky D and AB1 by other workers identifies a total of nine open reading frames (ORF). In this report, we present the DNA sequence of three of these newly identified ORFs, designated EUS 2, EUS 3, and EUS 4. The EUS 2 ORF is 1146 nucleotides (nt) in length and encodes a potential protein of 382 amino acids. Cis-regulatory sequences upstream of the putative ATG start codon include a G/C box 112 nt upstream and two potential TATA-like elements located between 15 and 90 nt before the ATG. The EUS 2 translation product exhibits significant homology to Ser/Thr protein kinases encoded within the Us segments of other herpesviruses, such as herpes simplex virus (26% homology) and pseudorabies virus (PRV), (45% homology), and possesses sequence domains conserved in protein kinases of cellular and viral origin. The EUS 3 ORF begins 127 nt downstream from the EUS 2 stop codon and ends at a stop codon 1119 nt further downstream. A single TATA-like element maps 61 nt upstream of the ORF. This ORF encodes a potential protein of 373 amino acids and is a homolog of glycoprotein gX of PRV, as judged by overall homology of amino acid residues, cysteine displacement, and presence of potential glycosylation sites and signal sequence. Interestingly, the EUS 4 ORF encodes a potential membrane glycoprotein that does not exhibit homology to any reported protein sequence. The EUS 4 ORF encodes a 383 amino acid polypeptide with a sequence indicative of a signal sequence at its amino terminal end, glycosylation sites for N-linked oligosaccharides, and a transmembrane domain near its carboxyl terminus. Several cis-acting regulatory sequences lie upstream of this ORF. These findings support the observation that the short region of alphaherpesviruses show considerable variation in their genetic content and gene organization.

Amino Acid Sequence↗

PubMed1982

A membrane glycoprotein that accumulates intracellularly: cellular processing of the large glycoprotein of LaCrosse virus.

The intracellular transport and certain posttranslational modifications of the large glycoprotein (G1) of LaCrosse virus (LAC) in BHK cells have been studied. G1 from released LAC virus was characterized by complex oligosaccharides (endo H-resistant) and covalently attached fatty acid. Only a small fraction of total cellular G1 was present on the baby hamster kidney cell surface. Cell-surface G1 contained complex oligosaccharides, while total G1 in infected cells contained largely unprocessed (endo H-sensitive) oligosaccharides. In addition, cell G1 contained significantly less fatty acid than virion-associated G1. Pulse-chase experiments showed that the oligosaccharides of G1 were processed to the complex from much more slowly than the oligosaccharides of the vesicular stomatitis virus (VSV) glycoprotein (G). In addition, transit of LAC G1 to the cell surface and into extracellular virions was two to three fold slower than the transit of VSV G. Thus LAC G1 accumulates intracellularly and is only slowly processed by intracellular processing enzymes. Treatment with monensin caused accumulation in the cell of a form of G1 with partial sensitivity toward endo H, suggesting that monensin may act to inhibit the glycosylation process directly.

Animals↗

PubMed1996

The acute phase response of acid soluble glycoprotein, alpha(1)-acid glycoprotein, ceruloplasmin, haptoglobin and C-reactive protein, in the pig.

The acute phase serum protein response to infection, inflammation or trauma has been identified in a number of species and consists of alterations to the serum concentrations of several proteins. It is known that the profile of acute phase protein response to stimulation differs between species. In the pig, individual proteins have been identified as acute phase proteins in association with infection or pathological lesions. In this investigation, turpentine injection was used to stimulate a sterile inflammatory lesion in pigs so that the relative changes in acute phase protein could be determined and the most appropriate proteins identified as markers of inflammation. The mean serum concentration of the acid soluble glycoprotein fraction showed a two-fold increase with a peak 2 days after treatment. The mean serum alpha(1)-acid glycoprotein concentration fluctuated during the period following injection of turpentine with little difference from the control animals. The mean concentration of serum ceruloplasmin increased by 40% by the 4th day following treatment. The mean serum concentration of haptoglobin increased more than two-fold reaching a peak on the 2nd day after treatment. The mean serum C-reactive protein level increased eight-fold with a peak on the 2nd day after turpentine injection. C-reactive protein and haptoglobin are likely to be the best markers for the identification of inflammatory lesions in pigs.

Acute-Phase Proteins↗

PubMed1988

Monoclonal antibodies directed against a 130K glycoprotein of bovine herpesvirus 2 cross-react with glycoprotein B of herpes simplex virus.

Envelope proteins of bovine herpesvirus type 2 (BHV-2) and herpes simplex virus types 1 and 2 (HSV-1, -2) share cross-reacting determinants. Monoclonal antibodies directed against epitopes of a 130K glycoprotein of BHV-2 detect determinants on the surface of infected cells and react either with cytoplasmic or nuclear antigens. Biological and biochemical characterization of the proteins recognized by these antibodies revealed that the BHV-2 specific 130K glycoprotein and the gB of HSV share common epitopes. Some of them are involved in the neutralization of HSV and BHV-2.

Antibodies, Monoclonal↗

PubMed1987

The acute phase response to inflammation: the role of monokines in changes in liver glycoproteins and enzymes of glycoprotein metabolism.

The role of monocyte derived factors in the acute phase response to inflammation is discussed. The kinetics of response of alpha 1-acid glycoprotein, sialyltransferase and albumin to a rat monokine preparation is described. There was an increase in synthesis of alpha 1-acid glycoprotein and sialyltransferase and a decrease in albumin synthesis following administration. However, the kinetics of response of sialyltransferase to the monokine was much slower than was found for the other two proteins. The possibility that sialyltransferase responds to a different monokine compared to the other acute phase proteins is discussed.

Acute-Phase Reaction↗

PubMed1975

Immunochemical and chemical investigations of the structure of glycoprotein fragments obtained from epiglycanin, a glycoprotein at the surface of the TA3-Ha cancer cell.

The structures of the carbohydrate chains present in fragments of a large-molecular-weight glycoprotein, epiglycanin, cleaved from the surface of viable TA3-Ha murine mammary carcinoma ascites cells and purified by gel filtration, were studied by immunochemical and chemical methods. Inhibitory activities for neuraminidase-treated and untreated glycoprotein material in the hemagglutination of NN-specific human erythrocytes by eight purified lectins were determined. Excellent inhibition was obtained in the Bauhinia purpurea, Arachis hypogaea, Iberis amara, and Wistaria floribunda systems, and weak inhibition against the Ricinus communis and Glycine max lectins. No activity against hemagglutination by the Phaseolus vulgaris and Phaseolus limensis lectins was observed. These results, when compared with those obtained by periodate oxidation, alkaline borohydride reduction, and partial methylation, suggest the possible presence of six different carbohydrate chains of 1 to 5 components in length, having as terminal groups N-acetylneuraminic acid, galactose, and 2-acetamido-2-deoxygalactose. All chains are attached to a single polypeptide chain by O-glycosyl bonds involving a 2-acetamido-2-deoxygalactose residue and a serine or threonine residue. It is suggested that the native molecule of epiglycanin of molecular weight 500,000 contains more than 500 carbohydrate chains attached to a single polypeptide chain of similar to 1,300 amino acid units.

Amino Acids↗

PubMed1987

Sulfate and phosphate analysis in glycoproteins and other biologic compounds using ion chromatography. Application to glycoprotein hormones and sugar esters.

An ion chromatography procedure was devised for the simultaneous determination of phosphate and sulfate in the same sample. In order to eliminate interference from zwitterionic compounds (particularly amino acids and peptides) generated during hydrolysis of the phosphate- or sulfate-containing compounds a pretreatment step with a cation-exchange column was required. The detection of sulfate is approximately twice as sensitive as phosphate on a molar basis. The useful working range for sulfate was 200 pmole to 35 nmole with the ion chromatography employed; the range for phosphate was 400 pmole to 65 nmole. Linearity in this range was very satisfactory. Representative analyses are presented for hydrolyzates of several glycoprotein hormones and sugar sulfates and phosphate esters. Replicate analyses were +/- 3.0% or better. The glycoprotein hormone analyses for sulfate did not indicate whole integers per mole, suggesting mixtures of isohormones as has been found by others using chromatofocusing or isoelectric focussing and immunoassay.

Animals↗

PubMed2000

Gum arabic glycoprotein contains glycomodules of both extensin and arabinogalactan-glycoproteins.

Gum arabic glycoprotein (GAGP) is a large molecular weight, hydroxyproline-rich arabinogalactan-protein (AGP) component of gum arabic. GAGP has a simple, highly biased amino acid composition indicating a repetitive polypeptide backbone. Previous work (Qi, W., Fong, C., Lamport, D.T.A., 1991. Plant Physiology 96, 848), suggested small (approximately 11 residue) repetitive peptide motifs each with three Hyp-arabinoside attachment sites and a single Hyp-arabinogalactan polysaccharide attachment site. We tested that hypothesis by sequence analysis of the GAGP polypeptide after HF-deglycosylation. A family of closely related peptides confirmed the presence of a repetitive 19-residue consensus motif. However, the motif: Ser-Hyp-Hyp-Hyp-Thr-Leu-Ser-Hyp-Ser- Hyp-Thr-Hyp-Thr-Hyp-Hyp-Leu-Gly-Pro-His, was about twice the size anticipated. Thus, judging by Hyp-glycoside profiles of GAGP, the consensus motif contained six Hyp-arabinosides rather than three and two Hyp-polysaccharides rather than one. We inferred the glycosylation sites based on the Hyp contiguity hypothesis which predicts arabinosides on contiguous Hyp residues and arabinogalactan polysaccharides on clustered non-contiguous Hyp residues, i.e. the GAGP motif would consist of arabinosylated contiguous Hyp blocks flanking two central Hyp-polysaccharides. We predict this rigidifies the glycoprotein, enhances the overall symmetry of the glycopeptide motif, and may explain some of the remarkable properties of gum arabic.

Amino Acid Motifs↗

PubMed2002

Encephalitogenic and immunogenic potential of myelin-associated glycoprotein (MAG), oligodendrocyte-specific glycoprotein (OSP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in ABH and SJL mice.

Synthetic peptides of myelin-associated glycoprotein (MAG), oligodendrocyte-specific glycoprotein (OSP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) were screened for their ability to induce experimental allergic encephalomyelitis (EAE) in ABH (H-2A(g7)) and SJL (H-2(s)) mice. The use of overlapping 16mer MAG peptides identified residues 97-112 as a T-cell and encephalitogenic epitope in ABH mice which induced clinical and histological signs of acute EAE. Immunization of SJL mice with MAG peptides failed to induce disease whereas immunization of SJL mice with synthetic peptides of OSP induced major T-cell responses to OSP 73-88 and 81-96. Another epitope, OSP 57-72, that induced EAE, failed to induce T-cell responses in mice immunised with peptides based on the whole sequence supporting a role for cryptic epitopes. In comparison, whilst immunization of ABH mice with OSP revealed two immunodominant T-cell epitopes (49-64 and 137-152), an encephalitogenic epitope was not identified. Similarly, immunization of both SJL and ABH mice with CNPase peptides induced T-cell responses to several epitopes. However, these were not encephalitogenic. This study is the first to identify an encephalitogenic epitope of MAG and immunodominant epitopes of MAG, OSP and CNPase in SJL and ABH mice. The ability of both cryptic and noncryptic peptide epitopes of these myelin antigens to initiate EAE suggests that mice at least are not tolerant to some regions of MAG and OSP and that such specific autoimmune responses may play an important role in the pathogenesis of immune-mediated neurological diseases such as multiple sclerosis.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed1995

Human platelet glycoproteins V and IX: mapping of two leucine-rich glycoprotein genes to chromosome 3 and analysis of structures.

Human platelet glycoproteins Ib alpha, Ib beta, V, and IX comprise an interrelated set of molecules (the Ib-V-IX system) that together form a surface adhesion receptor for the ligand, von Willebrand factor. To complete the primary structural characterization of the genes involved in this system, we have analyzed cosmid clones for both the glycoprotein V and IX genes and used these clones to localize the two genes by fluorescence in situ hybridization. Both genes were found on the long arm of chromosome 3, but at distinct sites, the GPV gene on 3 band q29 and the GP IX gene on 3 band q21. The transcriptional start site of the GPV gene was defined by "anchored" PCR and primer extension. The GPV gene contains two exons, the first consisting of approximately 37 bases and the second of approximately 3500 bases, interrupted by a single 958 base intron. The GPV transcript has multiple start sites spread over a twenty base region. The 5' flanking region of the GPV gene has a series of potential consensus regulatory elements including GATA, ets, and Sp-1 sites, similar to those found in other described megakaryocyte/platelet genes, including those of the Ib-V-IX system. In assessing the four Ib-V-IX genes as a group, all four have a simple, "intron-depleted" structure with the entire open reading frame of the mature polypeptide located within a single exon.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

PubMed2001

Anti-P-glycoprotein antibody-induced apoptosis of activated peripheral blood lymphocytes: a possible role of P-glycoprotein in lymphocyte survival.

P-glycoprotein (P-gp) is a 170-kDa glycoprotein encoded by the MDR-1 gene. In tumor cells overexpression of P-gp is associated with resistance to chemotherapy-induced apoptosis. P-gp is also expressed on cells of the immune system; however, its role in lymphocyte physiology remains unclear. Therefore, in this investigation, we examined a possible role of P-gp in the survival of in vitro activated peripheral blood mononuclear cells (MNCs). MNCs were activated with anti-CD3 monoclonal antibody (mAb) for 96 hr in the presence or absence of anti-P-gp mAb or isotype control and examined for apoptosis by TUNEL assay. Activation of caspase was determined by colorimetric assay. Activated lymphocytes (96 hr) are resistant to apoptosis. However, anti-P-gp mAb-induced apoptosis in anti-CD3 activated MNC. Induction of apoptosis was associated with increased expression of CD95L; activation of caspase 3, however, did not affect the expression of Bcl-2 and Bcl-xL. Furthermore, both recombinant Fas-Fc fusion protein, a blocker of CD95-CD95L interactions, and Z-DEVD-FMK, a cell-permeable caspase 3 inhibitor, reversed anti-P-gp-induced apoptosis. These data demonstrate that anti-P-gp mAb promotes apoptosis in activated T lymphocytes by up-regulating CD95L expression and via CD95-CD95L interactions and suggest a possible role of P-gp in lymphocyte survival.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1980

A variant surface glycoprotein of Trypanosoma brucei synthesized with a C-terminal hydrophobic 'tail' absent from purified glycoprotein.

Sequential expression of variant surface glycoproteins (VSGs) enables the parasitic protozoan Trypanosoma brucei to evade the immune response of its mammalian hosts. Studies of several VSGs, which have been isolated as soluble molecules following disruption of cells in the absence of detergent, have indicated extensive amino acid diversity and the absence of a hydrophobic segment which might serve to anchor the carboxy terminus to the membrane. The carboxy-terminal tryptic peptides of six VSGs have recently been characterized and shown to be glycosylated. Three of these VSGs terminated with a glycosylated aspartate or asparagine residue (Asx), suggesting that the VSG was cleaved following synthesis and glycosylation and before characterization. We present here nucleotide sequence data which suggest that the primary translation product of one VSG gene contains a hydrophobic tail at the carboxy terminus which is not found on the isolated, mature glycoprotein. The data also predict that the glycosylated residue is aspartic acid rather than the anticipated asparagine.

Amino Acid Sequence↗

PubMed1991

The oligosaccharides of glycoproteins: bioprocess factors affecting oligosaccharide structure and their effect on glycoprotein properties.

In this review, we organize the recent data concerning the effects of bioprocess factors on the oligosaccharide structure of human therapeutic glycoproteins, with particular emphasis on the influence of the host cell. We also discuss the effect of oligosaccharide structure on glycoprotein properties, including antigenicity, immunogenicity and plasma clearance rate.

Animals↗