Flexibility analysis and structure comparison of two crystal forms of calcium-free human m-calpain
| Autor: | Stefan Strobl, Hiroyuki Sorimachi, Marianne Braun, Wolfram Bode, David Reverter, Carlos Fernandez-Catalan |
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| Rok vydání: | 2002 |
| Předmět: |
Models
Molecular Stereochemistry Protein Conformation Proteolysis Clinical Biochemistry Static Electricity chemistry.chemical_element Context (language use) Calcium Crystallography X-Ray Biochemistry Protein structure medicine Humans Binding site Molecular Biology Binding Sites medicine.diagnostic_test biology Calpain chemistry Biophysics biology.protein Signal transduction Intracellular |
| Zdroj: | Biological chemistry. 383(9) |
| ISSN: | 1431-6730 |
| Popis: | The calpains form a growing family of structurally related intracellular multidomain cysteine proteinases containing a papain-related catalytic domain, whose activity depends on calcium. The calpains are believed to play important roles in cytoskelatel remodeling processes, cell differentiation, apoptosis and signal transduction, but are also implicated in a number of diseases. Recent crystal structures of truncated rat and full-length human apo-m-calpain revealed the domain arrangement and explained the inactivity of m-calpain in the absence of calcium by a disrupted catalytic domain. Proteolysis studies have indicated several susceptible sites, in particular in the catalytic subdomain IIb and in the following domain III, which are more accessible to attacking proteinases in the presence than in the absence of calcium. The current view is that m-calpain exhibits a number of calcium binding sites, which upon calcium binding cooperatively interact, triggering the reformation of a papain-like catalytic domain, accompanied by enhanced mobilisation of the whole structure. To further analyse the flexibility of m-calpain, we have determined and refined the human full-length apo-m-calpain structure of a second crystal form to 3.15 A resolution. Here we present this new structure, compare it with our first structure now re-refined with tighter constrain parameters, discuss the flexibility in context with the proteolysis and calcium binding data available, and suggest implications for the calcium-induced activation process. |
| Databáze: | OpenAIRE |
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