The glycoprotein tissue-type plasminogen activator (t-PA) is subject to hepatic clearance in humans. Here, the interaction of t-PA with a well-differentiated hepatoma cell line (HepG2) was examined. Suspended HepG2 cells bound '25I-t-PA in a specific, saturable, and reversible fashion through a Ca2'-dependent, active site-independent mechanism. Binding isotherms indicated a high affinity system...

The novel highly sulfated (35%) fucoidan fraction Cf2 , which contained, along with fucose, galactose and traces of xylose and uronic acids was purified from the brown alga Coccophora langsdorfii. Its structural features were predominantly determined (in comparison with fragments of known structure) by a rapid mass spectrometric investigation of the low-molecular-weight fragments, obtained by "...

Glycoprotein fucosylation enables fringe-dependent modulation of signal transduction by Notch transmembrane receptors, contributes to selectin-dependent leukocyte trafficking, and is faulty in leukocyte adhesion deficiency (LAD) type II, also known as congenital disorder of glycosylation (CDG)-IIc, a rare human disorder characterized by psychomotor defects, developmental abnormalities, and leuk...

Transport of D-glucose was studied in Percoll-gradient-purified rat liver lysosomes. D-Glucose uptake had a Km of 22 mM and a t1/2 of approx. 30 s. D-Fucose, 2-deoxyglucose and methyl alpha-glucoside were the most effective competitors for uptake of D-glucose, although D-galactose, D-mannose, D-xylose and L-fucose also appeared to compete for uptake. L-Glucose was a poor competitor for uptake. ...

alpha-1,3-Fucosyltransferase V (FucT V) catalyzes the transfer of 1-fucose from the donor sugar guanosine 5'-diphospho-beta-1-fucose (GDP-Fuc) to an acceptor sugar. A secondary isotope effect on the fucosyltransfer reaction with guanosine 5'-diphospho-[1-2H]-beta-1-fucose (GDP-[1-2H]-Fuc) as the substrate was observed and determined to be Dv = 1.32 +/- 0.13 and DV/K = 1.27 +/- 0.07. Competitive...

FucP of Escherichia coli catalyzes L-fucose/H(+) symport, and a crystal structure in an outward-facing conformation has been reported. However, nothing is known about FucP conformational dynamics. Here, we show that addition of L-fucose to purified FucP in detergent induces ∼20% quenching of Trp fluorescence in a concentration-dependent manner without a shift in λ(max). Quenching is essentially...

The presence of a pinocytosis receptor, specific for mannose-fucose terminated glycoproteins, has been established on murine resident peritoneal macrophages, thioglycollate-elicited peritoneal macrophages, and macrophages derived from bone-marrow in culture. Macrophagelike cell lines (J-774 and P338.D1), a myelomonocytic cell line (427E), lymphocytes, polymorphonuclear leukocytes, and fibroblas...

The enzyme propanediol oxidoreductase, which converts the lactaldehyde formed in the metabolism of fucose and rhamnose into propane-1,2-diol under anaerobic conditions, was investigated in Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. Structural analysis indicated that the enzymes of E. coli and K. pneumoniae have the same Mr and pI, whereas that of Salm. typhimurium also ...

Glycosaminoglycan was isolated from the body wall of sea cucumber Stichopus japonicus by a method consisting of enzymatic digestion, gel filtration, and ion-exchange chromatography. One gram of sea cucumber glycosaminoglycan was composed of 2.50 mmol of sulfate, 0.47 mmol of N-acetylgalactosamine (GalNAc), 0.53 mmol of glucuronic acid (GlcA), 1.73 mmol of fucose, and a small amount of peptide. ...

The present investigation was carried out to evaluate the protective role of Helicteres isora plant extract on glycoprotein metabolism in streptozotocin (STZ) induced type 2 diabetic rats. Helicteres isora plant extract was administered orally (200 mg/kg body weight) for 45 days to normal and diabetic rats. The effects of Helicteres isora plant extract on plasma and tissue glycoproteins (hexose...