Call us toll-free

T1 - Glycoprotein biosynthesis in yeast

Biosynthesis of intestinal glycoprotein: a study of an (1 lead to 2) fucosyltransferase in rat small intestinal mucosa.

Approximate price

Pages:

275 Words

$19,50

Halobacterial glycoprotein biosynthesis - ScienceDirect

ß1,4 Galactosyltransferase (GT) is the enzymatic subunit of lactose synthase. It is a glycoprotein with a molecular weight varying from 35-60 kDa, depending upon the amount of glycosylation and the degree of proteolytic degradation. ß1,4 Galactosyltransferase in milk is proteolytically clipped removing the cytoplasmic and transmembrane domains. The GT found in milk has a molecular weight of 35-45 kDa. Without the presence of -lactalbumin, the enzyme functions in the Golgi during glycoprotein biosynthesis to add galactose to oligosaccharides with terminal -acetylglucosamine residues in a ß1-->4 linkage. The GT transfers galactose from the donor, UDP-galactose, to the terminal -acetylglucosamine (GlcNAc) acceptor on the oligosaccharise complex of glycosylated proteins. Galactosyltransferase is found in most tissues of the body. It is only found on the inner surface of the Golgi apparatus.

Glycoprotein biosynthesis in small intestine - Europe …

Endosomes are the site of sorting of internalized receptors and ligands in all cell types and, in polarized cells, the apical endosomal compartment is involved in the selective trans-epithelial transport of immunoglobulins and growth factors. The biochemical composition of this specialized compartment remains largely unresolved. We have characterized a glycoprotein, called endotubin, that is located in the apical endosomal tubules of developing rat intestinal epithelial cells. A monoclonal antibody against endotubin recognizes a broad band of 55-60 kDa, which upon isoelectric focusing can be resolved into two bands, and a faint band of 140 kDa. Metabolic labelling followed by immunoprecipitation indicates that endotubin is synthesized as a 140 kDa precursor that is cleaved to the 55-60 kDa forms. High pH washing of endosomal membranes removes the 55-60 kDa forms from the membrane, whereas the high-molecular-mass form remains membrane associated and appears to be an integral membrane protein. Immunoblotting with a polyclonal antibody against the putative cytoplasmic tail of the protein identifies a 140 kDa band and a band of 74 kDa, presumably the cleavage product. Immunoprecipitation with antibodies against the 55-60 kDa form results in coprecipitation of a 74 kDa protein, and immunoprecipitation with antibody against the 74 kDa protein results in coprecipitation of the 55-60 kDa form. Epitope mapping of the monoclonal antibody binding site supports a proposed type I membrane protein orientation. We propose that endotubin is proteolytically processed into a heterodimer with the 55-60 kDa fragment remaining membrane-associated through a non-covalent association with the membrane-bound 74 kDa portion of the molecule.

Glycoprotein Biosynthesis in Chlamydomonas | Plant …

N2 - Synthesis and secretion of colonic mucin glycoprotein species were assessed during in vitro culture of colonic mucosal explants. DEAE-cellulose chromatography of endogenously labeled mucin glycoproteins from explant tissue demonstrated the presence of six mucin species (I-VI) similar to those identified earlier in surgical specimens of human colonic tissue. The relative proportions of mucin species I-VI in tissue explants remained constant throughout a 30-h culture period. However, the proportional representation of the various mucin species in media was significantly different from that found in tissue, which suggests that some mucin species (I, II, and III) are differentially secreted, whereas others (IV and V) are retained within intracellular pools. Radiolabeled precursors were incorporated into mucin species I, II, and III at a 2.0-2.6-fold greater rate than their concentration in tissue, supporting the concept that these glycoproteins were both synthesized and secreted at a greater rate than species IV and V. Colonic mucosal explants from patients with ulcerative colitis showed greater than 90% reduction of species IV. However, the amount of species IV recovered from culture media of ulcerative colitis explants was comparable to normal controls. It appears that mucin species IV is differentially secreted rather than retained within intracellular pools in mucosa of patients with ulcerative colitis.

Synthesis and secretion of colonic mucin glycoprotein species were assessed during in vitro culture of colonic mucosal explants. DEAE-cellulose chromatography of endogenously labeled mucin glycoproteins from explant tissue demonstrated the presence of six mucin species (I-VI) similar to those identified earlier in surgical specimens of human colonic tissue. The relative proportions of mucin species I-VI in tissue explants remained constant throughout a 30-h culture period. However, the proportional representation of the various mucin species in media was significantly different from that found in tissue, which suggests that some mucin species (I, II, and III) are differentially secreted, whereas others (IV and V) are retained within intracellular pools. Radiolabeled precursors were incorporated into mucin species I, II, and III at a 2.0-2.6-fold greater rate than their concentration in tissue, supporting the concept that these glycoproteins were both synthesized and secreted at a greater rate than species IV and V. Colonic mucosal explants from patients with ulcerative colitis showed greater than 90% reduction of species IV. However, the amount of species IV recovered from culture media of ulcerative colitis explants was comparable to normal controls. It appears that mucin species IV is differentially secreted rather than retained within intracellular pools in mucosa of patients with ulcerative colitis.

glycoproteins | Nucleotides | Biosynthesis

AB - Synthesis and secretion of colonic mucin glycoprotein species were assessed during in vitro culture of colonic mucosal explants. DEAE-cellulose chromatography of endogenously labeled mucin glycoproteins from explant tissue demonstrated the presence of six mucin species (I-VI) similar to those identified earlier in surgical specimens of human colonic tissue. The relative proportions of mucin species I-VI in tissue explants remained constant throughout a 30-h culture period. However, the proportional representation of the various mucin species in media was significantly different from that found in tissue, which suggests that some mucin species (I, II, and III) are differentially secreted, whereas others (IV and V) are retained within intracellular pools. Radiolabeled precursors were incorporated into mucin species I, II, and III at a 2.0-2.6-fold greater rate than their concentration in tissue, supporting the concept that these glycoproteins were both synthesized and secreted at a greater rate than species IV and V. Colonic mucosal explants from patients with ulcerative colitis showed greater than 90% reduction of species IV. However, the amount of species IV recovered from culture media of ulcerative colitis explants was comparable to normal controls. It appears that mucin species IV is differentially secreted rather than retained within intracellular pools in mucosa of patients with ulcerative colitis.

N2 - Endosomes are the site of sorting of internalized receptors and ligands in all cell types and, in polarized cells, the apical endosomal compartment is involved in the selective trans-epithelial transport of immunoglobulins and growth factors. The biochemical composition of this specialized compartment remains largely unresolved. We have characterized a glycoprotein, called endotubin, that is located in the apical endosomal tubules of developing rat intestinal epithelial cells. A monoclonal antibody against endotubin recognizes a broad band of 55-60 kDa, which upon isoelectric focusing can be resolved into two bands, and a faint band of 140 kDa. Metabolic labelling followed by immunoprecipitation indicates that endotubin is synthesized as a 140 kDa precursor that is cleaved to the 55-60 kDa forms. High pH washing of endosomal membranes removes the 55-60 kDa forms from the membrane, whereas the high-molecular-mass form remains membrane associated and appears to be an integral membrane protein. Immunoblotting with a polyclonal antibody against the putative cytoplasmic tail of the protein identifies a 140 kDa band and a band of 74 kDa, presumably the cleavage product. Immunoprecipitation with antibodies against the 55-60 kDa form results in coprecipitation of a 74 kDa protein, and immunoprecipitation with antibody against the 74 kDa protein results in coprecipitation of the 55-60 kDa form. Epitope mapping of the monoclonal antibody binding site supports a proposed type I membrane protein orientation. We propose that endotubin is proteolytically processed into a heterodimer with the 55-60 kDa fragment remaining membrane-associated through a non-covalent association with the membrane-bound 74 kDa portion of the molecule.

Order now
  • Glycoprotein Biosynthesis in a Eukaryote …

    Biosynthesis of glycoproteins

  • Bacterial glycoproteins: Functions, biosynthesis and applications

    Glycoprotein Biosynthesis in a Eukaryote Lacking the Membrane Protein ..

  • Bacterial glycoproteins: Functions, biosynthesis and ..

    Glycoprotein biosynthesis was studied with mouse L-cells grown in suspension culture

Order now

Glycoprotein Biosynthesis at the Time of Palate Fusion …

AB - The biosynthesis, processing, and half-life of the drug efflux pump, P-glycoprotein, were studied in human multidrug-resistant KB (KB-C2) cells selected for resistance to colchicine. An antibody directed against a synthetic oligopeptide corresponding to the amino-acid sequence (Glu-393-Lys-408) of P-glycoprotein from human mdrl cDNA was prepared in rabbits. With immunoblotting and immunoprecipitation, we detected a 140-170 kDa protein in KB-C2 cells but not in parental sensitive KB cells. KB-C2 cells made a 125 kDa precursor that was slowly processed (t 1 2 = 45 min) to the mature form of 140-150 kDa. The processing rate of P-glycoprotein was slower than that of low-density lipoprotein receptor. We detected another 160-180 kDa smear band, which might be a completely denatured form of P-glycoprotein. With immunoblotting, a minor band of high molecular mass (greater than 500 kDa) was also detected and this form increased after the cells were treated with chemical cross-linker, 1,5-difluoro-2,4-dinitrobenzene. The half-life of P-glycoprotein was long; no significant loss of P-glycoprotein was observed within 24 h after synthesis. Cells treated with tumicamycin produced a 120 kDa from of P-glycoprotein which was no longer processed but showed stability similar to that of the mature 140-150 kDa form. Agents that reverse multidrug resistance, phorbol ester and transport substrate did not affect the stability of P-glycoprotein.

Glycoprotein biosynthesis by human normal platelets - …

N2 - The biosynthesis, processing, and half-life of the drug efflux pump, P-glycoprotein, were studied in human multidrug-resistant KB (KB-C2) cells selected for resistance to colchicine. An antibody directed against a synthetic oligopeptide corresponding to the amino-acid sequence (Glu-393-Lys-408) of P-glycoprotein from human mdrl cDNA was prepared in rabbits. With immunoblotting and immunoprecipitation, we detected a 140-170 kDa protein in KB-C2 cells but not in parental sensitive KB cells. KB-C2 cells made a 125 kDa precursor that was slowly processed (t 1 2 = 45 min) to the mature form of 140-150 kDa. The processing rate of P-glycoprotein was slower than that of low-density lipoprotein receptor. We detected another 160-180 kDa smear band, which might be a completely denatured form of P-glycoprotein. With immunoblotting, a minor band of high molecular mass (greater than 500 kDa) was also detected and this form increased after the cells were treated with chemical cross-linker, 1,5-difluoro-2,4-dinitrobenzene. The half-life of P-glycoprotein was long; no significant loss of P-glycoprotein was observed within 24 h after synthesis. Cells treated with tumicamycin produced a 120 kDa from of P-glycoprotein which was no longer processed but showed stability similar to that of the mature 140-150 kDa form. Agents that reverse multidrug resistance, phorbol ester and transport substrate did not affect the stability of P-glycoprotein.

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order