Elucidation of the Substrate Specificity of the C1s Protease of the Classical Complement Pathway
| Autor: | James C. Whisstock, Phillip I. Bird, Felicity Kate Kerr, Dion Kaiserman, Sarah Elizabeth Boyd, Maria Garcia de la Banda, Antony Yaron Matthews, Noelene Sheila Quinsey, Robert N. Pike, Grace O'Brien |
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| Rok vydání: | 2005 |
| Předmět: |
Models
Molecular Phage display medicine.medical_treatment In Vitro Techniques Biology Biochemistry Substrate Specificity Classical complement pathway Peptide Library Catalytic Domain medicine Humans Amino Acid Sequence Complement Pathway Classical Peptide library Molecular Biology Peptide sequence chemistry.chemical_classification Binding Sites Protease Base Sequence Complement C1s Active site DNA Cell Biology Complement system Enzyme chemistry biology.protein Oligopeptides |
| Zdroj: | Journal of Biological Chemistry. 280:39510-39514 |
| ISSN: | 0021-9258 |
| Popis: | The complement system is a central component of host defense but can also contribute to the inflammation seen in pathological conditions. The C1s protease of the first complement component, the C1 complex, initiates the pathway. In this study we have elucidated the full specificity of the enzyme for the first time using a randomized phage display library. It was found that, aside from the crucial P(1) position, the S(3) and S(2) subsites (in that order) played the greatest role in determining specificity. C1s prefers Leu or Val at P(3) and Gly or Ala residues at P(2). Apart from the S(2)' position, which showed specificity for Leu, prime subsites did not greatly affect specificity. It was evident, however, that together they significantly contributed to the efficiency of cleavage of a peptide. A peptide substrate based on the top sequence obtained in the phage display validated these results and produced the best kinetics of any C1s substrate to date. The results allow an understanding of the active site specificity of the C1s protease for the first time and provide a basis for the development of specific inhibitors aimed at controlling inflammation associated with complement activation in adverse pathological situations. |
| Databáze: | OpenAIRE |
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