UDP-GlcNAc:alpha3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I (GnTI; EC 2.4.1.
View Article and Find Full Text PDFMurine SCC-VII squamous carcinoma cells have the capacity to penetrate reconstituted basement membranes (Matrigel) in vitro. The invasion of Matrigel layers by SCC-VII cells was significantly reduced by E-64, a specific inhibitor of lysosomal cysteine proteinases. The cathepsin-B-selective E-64 derivative, CA-074, inhibited penetration of Matrigel by SCC-VII cells to the same extent, indicating a major role for this particular lysosomal enzyme in extracellular-matrix degradation during squamous-carcinoma-cell invasion.
View Article and Find Full Text PDFIn plants as well as in animals beta1, 2N-acetylglucosaminyltransferase I (GlcNAc-TI) is a Golgi resident enzyme that catalyzes an essential step in the biosynthetic pathway leading from oligomannosidic N-glycans to complex or hybrid type N-linked oligosaccharides. Employing degenerated primers deduced from known GlcNAc-TI genes from animals, we were able to identify the cDNA coding for GlcNAc-TI from a Nicotiana tabacum cDNA library. The complete nucleotide sequence revealed a 1338 base pair open reading frame that codes for a polypeptide of 446 amino acids.
View Article and Find Full Text PDFA fragment of the human low-density lipoprotein receptor encompassing the seven ligand-binding repeats fused to a C-terminal oligo-His tag was expressed in Sf9 insect cells. The melittin signal sequence encoded in the baculovirus vector led to secretion of the protein into the cell supernatant in a soluble form. The receptor fragment bound its natural ligand beta-migrating very-low-density lipoprotein and human rhinovirus serotype 2 in non-reducing ligand blots.
View Article and Find Full Text PDFA fragment of the low density lipoprotein receptor encompassing the seven ligand binding repeats was expressed in Sf9 insect cells as a fusion protein with a carboxyl-terminally linked hexa-his tag by using a baculovirus vector. Up to 10 mg/l of the fusion protein was secreted into the medium. The material was soluble in the absence of detergent and active in binding beta very low density lipoprotein and a member of the minor group of human rhinoviruses (HRV2) in ligand blots from sodium dodecyl sulfate-polyacrylamide gels run under nonreducing conditions.
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