Inoue M, Karita H, Kikuchi K, Nakayama C, Noguchi H
Sumitomo Pharmaceuticals Research Center, Osaka, Japan.
J Neurochem. 1997 Apr;68(4):1436-42. doi: 10.1046/j.1471-4159.1997.68041436.x.
The structure-function relationships of human ciliary neurotrophic factor (CNTF) were analyzed by mutagenic means. Amino acid substitutions at helix D caused marked changes in the biological activity of CNTF, suggesting that the residues at helix D of CNTF participate in receptor recognition. In particular, both the cell survival-promoting activity and receptor binding ability of V170 mutant CNTF proteins correlated well with the hydrophobicity of amino acids at position 170. The reduction of hydrophobicity at position 170 resulted in a loss of biological activity, indicating that the hydrophobicity of V170 is essential for the receptor binding and cell survival-promoting activity. Substitutions of R171 or D175 evoked very little folding ability and negated the biological activity of CNTF. As R171 and D175 interact electrostatically with each other and with E75 and R72, respectively, these interactions would be indispensable for stabilizing the whole CNTF protein and for maintaining the structure of the receptor binding epitope.
通过诱变手段分析了人睫状神经营养因子（CNTF）的结构-功能关系。螺旋D处的氨基酸取代导致CNTF的生物学活性发生显著变化，这表明CNTF螺旋D处的残基参与受体识别。特别是，V170突变型CNTF蛋白的细胞存活促进活性和受体结合能力与170位氨基酸的疏水性密切相关。170位疏水性的降低导致生物活性丧失，表明V170的疏水性对于受体结合和细胞存活促进活性至关重要。R171或D175的取代引起的折叠能力非常小，并消除了CNTF的生物学活性。由于R171和D175分别与E75和R72静电相互作用，这些相互作用对于稳定整个CNTF蛋白和维持受体结合表位的结构必不可少。
