3.2.1.166 glycoprotein 4 potential N-glycosylation sites 692954 3.2.1.166 glycoprotein enzyme HPSE contains 6 putative N-glycosylation sites, all residing on the 50 kDa subunit. N-linked GlcNAcs (corresponding to N-glycan trees trimmed by endoglycosidase (Endo)H during protein preparation) are found in the apo-HPSE structure at Asn162, Asn200, Asn217, Asn238 and Asn459. Additionally a core alpha1->6 linked fucose is located on the GlcNAc linked to Asn459. No noticeable density corresponding to GlcNAc is observed at the N-glycosylation site Asn178, suggesting this position may not be well N-glycosylated during baculoviral expression, or that N-GlcNAc here is not compatible with crystal packing 754873 3.2.1.166 glycoprotein glycosylation of Hpa1 is essential for solubility 690801 3.2.1.166 glycoprotein synthesized as an inactive 65000 Da glycoprotein that is cleaved at the N-terminus to generate the active enzyme 692520 3.2.1.166 glycoprotein the enzyme contains six N-glycosylation sites 731884 3.2.1.166 glycoprotein the enzyme contains six N-linked oligosaccharides 693320 3.2.1.166 proteolytic modification an endo-acting binding cleft is exposed by proteolytic activation of latent proenzyme, proHPSE. Enzyme HPSE is initially translated as a pre-proenzyme, containing a signal sequence spanning Met1-Ala35. Cleavage of this signal sequence by signal peptidase leaves an inactive 65 kDa proHPSE, which must undergo further processing for activity. Proteolytic removal by cathepsin L of a linker spanning Ser110-Gln157 liberates an N-terminal 8 kDa subunit and a C-terminal 50 kDa subunit, which remain associated as a non-covalent heterodimer in mature active HPSE29 754873 3.2.1.166 proteolytic modification heparanase is initially translated as a preproenzyme containing a signal sequence spanning Met1-Ala35. Cleavage of this signal sequence by signal peptidase yields an inactive 65-kDa pro-heparanase, which must undergo further processing for activity. Proteolytic removal by cathepsin L of a linker spanning Ser110-Gln157 liberates an N-terminal 8-kDa subunit and a C-terminal 50-kDa subunit, which remain associated as a noncovalent heterodimer in mature active heparanase. Processing of heparanase is mediated by syndecan 1 cytoplasmic domain and involves syntenin and alpha-actinin. Heparanase uptake is regarded a pre-requisite for the delivery of latent 65 kDa heparanase to lysosomes and its subsequent proteolytic processing and activation into 8 and 50 kDa protein subunits 753404 3.2.1.166 proteolytic modification heparanase-1 is synthesized as an inactive precursor of about 65000 Da that subsequently undergoes proteolytic cleavage, yielding 8000 Da and 50000 Da protein subunits that heterodimerize to form the active enzyme. The protein contains a putative N-terminal signal peptide (Met1-Ala35) and a C-terminal hydrophobic region (Pro515-Ile534) 693320 3.2.1.166 proteolytic modification Hpa1 protein is initially synthesized as an inactive 65000 Da proenzyme and subsequently activated by proteolytic cleavage to generate an active heterodimer of 8000 Da and 50000 Da polypeptides 690801 3.2.1.166 proteolytic modification synthesized as an inactive 65000 Da glycoprotein that is cleaved at the N-terminus to generate the active enzyme 692520 3.2.1.166 proteolytic modification the 65 kDa precursor polypeptide that is enzymatically inactive. Proteolytic activation by cleavage into two fragments 732436 3.2.1.166 proteolytic modification the 65 kDa precursor polypeptide that is enzymatically inactive. Proteolytic excision by cathepsin L of a 48 amino acid peptide yields an active heterodimer comprising 8 and 50 kDa subunits 731586, 731867 3.2.1.166 proteolytic modification the 8000 Da and 50000 Da chains which make up the active enzyme reside, respectively, at the NH2-terminal and COOH-terminal regions of the inactive precursor, proheparanase. The heparanase heterodimer is produced by excision and loss of an internal linking segment 692947 3.2.1.166 proteolytic modification the full-length chicken heparanase cDNA encodes a 60000 Da proenzyme that is processed at the N-terminus into a 45000 Da highly active enzyme. The signal peptide sequence accounts for the chicken heparanase being readily secreted and localized in close proximity to the cell surface 692954