A Structure-function Analysis of the Human Ciliary Neurotrophic Factor.
The ciliary neurotrophic factor (CNTF) plays a very important role in the development and regeneration of the nervous system. In this study, the prediction of secondary structure and the hydrophobicity analysis of human CNTF were performed according to the amino acid sequence deduced from the nucleotide sequence of the cDNA. Based on the results of the prediction of structure, the human CNTF gene was modified by insertion and deletion mutagenesis. The various mutants were all highly expressed in E. coli. The recombinant proteins were purified from bacterial via DEAE A-50 and Sephacryl S-200 chromatography, and their survival-promoting activities were determined by using cultures of the dorsal root ganglion neurons of embryonic chick. The results showed that the alpha-helixes in CNTF were critical for the biological activity and the flexible C-terminus of human CNTF was not essential. Our data also indicated that the middle and the tail part of the D-helix might play crucial roles in the biological functions of CNTF.
He
Cheng
C
National Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, Shanghai 200031, China.
Chen
Jian-Ye
JY
Lu
Chang-Lin
CL
Ao
Shi-Zhou
SZ