Study of the Structure and Biological Activity of the Amino-Terminus of the α-Toxin from Clostridium welchii Type A
Autor: | Yuhan She, Chongli Xu, Chongbo Xu, Yimin Lin, Fengyang Fu |
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Rok vydání: | 2018 |
Předmět: |
Circular dichroism
Clostridium perfringens Protein Conformation Bacterial Toxins Biology Applied Microbiology and Biotechnology Microbiology 03 medical and health sciences Mice Structure-Activity Relationship Protein structure Structure–activity relationship Animals heterocyclic compounds Amino Acid Sequence Peptide sequence 030304 developmental biology chemistry.chemical_classification 0303 health sciences Antigens Bacterial Phospholipase C 030306 microbiology Calcium-Binding Proteins Biological activity General Medicine Molecular biology Amino acid chemistry Type C Phospholipases Glycine Mutation cardiovascular system Clostridium Infections Immunization |
Zdroj: | Current microbiology. 76(10) |
ISSN: | 1432-0991 |
Popis: | To explore the biological activity of Clostridium welchii α-toxin (CPA), the Asp56 residue of CPA was mutated to glycine (CPA D56G) by site-directed mutagenesis, and the 250 amino acid amino-terminal phospholipase C (PLC)-containing domain of CPA (PLC1-250) was isolated. The secondary and three-dimensional (3D) structures of CPA D56G and PLC1-250 were predicted, and the results showed that the secondary structures of CPA D56G and PLC1-250 were composed of α-helices and random coils. The 3D structures of CPA D56G and PLC1-250 were similar to the 3D structures of CPA. The circular dichroism (CD) spectrum of CPA D56G differed from the CD spectrum of CPA, but the CD spectrum of PLC1-250 was similar to the CD spectrum of CPA. Biological activity assays showed that CPA D56G lost the PLC activity of CPA and that mice immunized with CPA D56G were protected against a challenge with 1 MLD C. welchii type A strain C57-1. In addition, PLC1-250 contained the PLC activity of CPA. This study laid a solid foundation for future studies on the relationship between the molecular structure and biological function of CPA and its molecular mechanism. Our study also provided CPA D56G as a candidate strain for engineering a CPA subunit vaccine for C. welchii type A. |
Databáze: | OpenAIRE |
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