Rational design, solution conformation and identification of functional residues of the soluble and structured Nogo-54, which mimics Nogo-66 in inhibiting the CNS neurite outgrowth.
The interaction between Nogo-66 and its receptor NgR represents a promising target for designing drugs to treat CNS axonal injury which often leads to permanent disability. Unfortunately, the isolated Nogo-66 is highly insoluble while its truncated form Nogo-40 is soluble but unstructured, thus retarding further characterization and application. Here, we rationally design another soluble form Nogo-54. CD and NMR characterization reveals that Nogo-54 is structured, and importantly, is able to mimic Nogo-66 in inhibiting neurite outgrowth. Strikingly, mutating its C-terminal four residues (Lys50, Glu51, Arg53, and Arg54) leads to a mutant Nogo-54m which has no dramatic structural change but whose inhibitory activity is completely abolished. This strongly suggests that the four charged residues contribute significantly to the inhibitory action of Nogo-66. Furthermore, our study also provides a soluble and structured mimic as well as a possible antagonist for Nogo-66 which may hold promising potential for various medical applications.
Li
Minfen
M
Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore.
Li
Yali
Y
Liao
Xuanhao
X
Liu
Jingxian
J
Qin
Haina
H
Xiao
Zhi-cheng
ZC
Song
Jianxing
J
D000595:Amino Acid Sequence; D002490:Central Nervous System / Q000187:drug effects / Q000502:physiology; D002942:Circular Dichroism; D015195:Drug Design; D058851:GPI-Linked Proteins; D006801:Humans; D009154:Mutation; D009185:Myelin Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects* / Q000502:physiology; D000070798:Nogo Proteins; D000070816:Nogo Receptor 1; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D011956:Receptors, Cell Surface / Q000819:agonists / Q000037:antagonists & inhibitors; D012995:Solubility; D013329:Structure-Activity Relationship
D058851:GPI-Linked Proteins; D009185:Myelin Proteins; D000070798:Nogo Proteins; D000070816:Nogo Receptor 1; C000603199:RTN4 protein, human; C486580:RTN4R protein, human; D011956:Receptors, Cell Surface