| 학회 |
한국고분자학회 |
| 학술대회 |
2004년 봄 (04/09 ~ 04/10, 고려대학교) |
| 권호 |
29권 1호, p.344 |
| 발표분야 |
의료용 고분자 부문위원회 |
| 제목 |
The effect of sequence distribution on pH-dependent conformational change of amphipathic polypeptides |
| 초록 |
We have investigated the correlation between amino acid sequence and pH-induced helix-coil transition of amphipathic polypeptides using the finite Possion-Boltzmann method and an atomistic molecular dynamic simulation. The synthetic polypeptides (GALA and KALA) and the segments of fusion protein (residue 1~20 and residue 56~75) of influenza virus are generated as model helical structures. The finite difference Poisson-Boltzmann method was used to obtain the pKa values of each amino acid residue in the polypeptides, and the free energy of unfolding and the average charge of all ionizable residues were obtained as a function of pH. The obtained charge distributions are then used for the subsequent molecular dynamics as inputs. Our simulation results show that the helix percentages of the synthetic polypeptides at pH = 5 and pH = 7 agree well with the experimental results. The free energy change of the fusion peptide upon a decrease of pH is greater than those of the synthetic polypeptides. It is inferred from the calculation that although the ionizable residues of the fusion peptide are not distributed to form the hydrophilic face like the synthetic polypeptide, the sequence distribution of the fusion peptide may be optimized to maximize the interaction with the membrane of target cell and induce a large conformational change upon a decrease of pH. |
| 저자 |
최호섭, 허준, 조원호
|
| 소속 |
서울대 |
| 키워드 |
GALA; KALA; hemagglutinin; poisson-boltzmann calculation
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| E-Mail |
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