tailieunhanh - Báo cáo khóa học: Structural characterization of the human Nogo-A functional domains Solution structure of Nogo-40, a Nogo-66 receptor antagonist enhancing injured spinal cord regeneration

The recent discovery of theNogo family ofmyelin inhibitors and theNogo-66 receptor opens upa very promising avenue for the development of therapeutic agents for treating spinal cord injury. Nogo-A, the largest member of the Nogo fam-ily, is a multidomain protein containing at least two regions responsible for inhibiting central nervous system (CNS) regeneration. So far, no structural information is available for Nogo-A or any of its structural domains. We have sub-cloned and expressed two Nogo-A fragments, namely the 182 residueNogo-A(567–748) and the 66 residueNogo-66 in Escherichia coli | Eur. J. Biochem. 271 3512-3522 2004 FEBS 2004 doi Structural characterization of the human Nogo-A functional domains Solution structure of Nogo-40 a Nogo-66 receptor antagonist enhancing injured spinal cord regeneration Minfen Li1 Jiahai Shi1 Zheng Wei1 Felicia Y. H. Teng2 Bor Luen Tang2 and Jianxing Song1 2 1 Department of Biological Sciences and department of Biochemistry National University of Singapore Singapore The recent discovery of the Nogo family of myelin inhibitors and the Nogo-66 receptor opens up a very promising avenue for the development of therapeutic agents for treating spinal cord injury. Nogo-A the largest member of the Nogo family is a multidomain protein containing at least two regions responsible for inhibiting central nervous system CNS regeneration. So far no structural information is available for Nogo-A or any of its structural domains. We have subcloned and expressed two Nogo-A fragments namely the 182 residue Nogo-A 567-748 and the 66 residue Nogo-66 in Escherichia coli. CD and NMR characterization indicated that Nogo-A 567-748 was only partially structured while Nogo-66 was highly insoluble. Nogo-40 a truncated form of Nogo-66 has been previously shown to be a Nogo-66 receptor antagonist that is able to enhance CNS neuronal regeneration. Detailed NMR examinations revealed that a Nogo-40 peptide had intrinsic helix-forming propensity even in an aqueous environment. The NMR structure of Nogo-40 was therefore determined in the presence of the helix-stabilizing solvent trifluoroethanol. The solution structure of Nogo-40 revealed two well-defined helices linked by an unstructured loop representing the first structure of Nogo-66 receptor binding ligands. Our results provide the first structural insights into Nogo-A functional domains and may have implications in further designs of peptide mimetics that would enhance CNS neuronal regeneration. Keywords CNS neuronal regeneration NMR spectroscopy Nogo-40 NogoA .