Limited proteolysis of chicken gizzard 5'-nucleotidase
| Autor: | Ursula Stochaj, Hans Georg Mannherz, Matthias Cramer |
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| Rok vydání: | 1992 |
| Předmět: |
Models
Molecular Glycan Glycosylation Protein Conformation Proteolysis Biophysics Biochemistry 5'-nucleotidase Structural Biology Thermolysin Laminin Papain medicine Animals Chymotrypsin Trypsin Molecular Biology 5'-Nucleotidase Clostripain Binding Sites Membrane Glycoproteins biology medicine.diagnostic_test Chemistry Binding protein Cell Membrane Peptide Fragments Extracellular Matrix Cysteine Endopeptidases Gizzard Avian biology.protein Chickens medicine.drug |
| Zdroj: | Biochimica et biophysica acta. 1122(3) |
| ISSN: | 0006-3002 |
| Popis: | Chicken gizzard 5′-nucleotidase represents an ectoenzyme which is linked to the plasma membrane via a phosphatidylinositol glycan. We have characterized the possible domain-like organization of 5′-nucleotidase by limited proteolysis. A hydrophobic proteolytic fregment carrying the intact C-terminus, as well as two major hydrophilic productsm were identified. We developed procedures for specific radiolabelling of the active center of 5′-nucleotidase. This allowed us to locate the catalytic site within hydrophilic fragments obtained after limited proteolysis. We demonstrate that removal of N-linked carbohydrate chains increases the sensitivity of 5′-nucleotidase to proteolytic attack, indicating that sugar moieties protect against proteolysis. 5′-nucleotidase the sensitivity of 5′-nucleotidase to proteolytic attack, indicating that sugar moieties protect against proteolysis. 5′-Nucleotidase represents a binding protein for component of the extracellular matrix. The interaction between 5′-nucleotidase and the laminin/nidogen complex unmasked proteolytic cleavage sites in the C-terminal portion of the enzyme. This resulted in the specific production of a hydrophilic form of 5′-nucleotidase. In summary, we have further charcterized chicken gizzard 5′-nucleotidase: (1) the protein is organized into two domain-like structures, (2) the N-terminal domain harbors the active center; (3) N-linked carbohydrates protect the protein against proteolytic degradation; (4) interaction with components of the extracellular matrix alters the conformation of 5′-nucleotidase. |
| Databáze: | OpenAIRE |
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