Conformational study of a N-terminal deletion derivative of a fragment in MyoD bHLH region

• Main Authors: Yi-Shiung Chou, 周義雄
• Other Authors: Wei-Jyun Chien
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/47903189461299671537

碩士 === 朝陽科技大學 === 應用化學系碩士班 === 101 === MyoD is a DNA-bindingprotein protein. The HLH motif containing a cluster of amino acid rich in basic residues, could form heterodimer with E2A proteins to activate speficic gene expression. Id proteins act as negative regnlators of transcription factors within the basic helix-loop-helix family. A peptide analog, Peptide 3C derived from a fragment of MyoD was designecl. Peptide 3C showed high affinity for Id1 protein and inhibit the proliferation of several cancer cell.We synthesige an Peptide 3C derivative with deletion in N-terminal fragment (NH2-Leu-Gln-Ala-Leu-Leu-Arg-Asp-Gln-Cys-CONH2) and study the conformation charac tevic of the peptide.The results of circular dichroisn (CD) spectra showed that the peptide existed mainly as a random coil in agueous solution, Introduction of 50% TFE could induce the formation of helical conformation. Base on the experiment results nuclear magnetic resonance (NMR) spectra, under 50% TFE, the helix spanned the fragment of Ala3~Asp7. Our observations suggest that even with the possibility of the formation of helical conformation, it is not sufficient to facilitate the binding to Id1 protein the fragment in the N-terminal of Peptide 3C maybe more aucial to the binding to Id1 protein.