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- W2005506293 abstract "The Helmholtz free energy F (rather than the energy) is the correct criterion for stability; therefore, calculation of F is important for peptides and proteins that can populate a large number of metastable states. The local states (LS) method proposed by H. Meirovitch [(1977) Chemical Physics Letters, Vol. 45, p. 389] enables one to obtain upper and lower bounds of the conformational free energy, FB (b, l) and FA (b, l), respectively, from molecular dynamics (MD) or Monte Carlo samples. The correlation parameter b is the number of consecutive dihedral or valence angles along the chain that are taken into account explicitly. The continuum angles are approximated by a discretization parameter l; the larger are b and l, the better the approximations; while FA can be estimated efficiently, it is more difficult to estimate FB. The method is further developed here by applying it to MD trajectories of a relatively large molecule (188 atoms), the potent “Asp4-Dpr10” antagonist [cyclo(4/10)-(Ac-Δ3Pro1-D-pFPhe2-D-Trp3-Asp4-Tyr-5-D-Nal6-Leu7-Arg8-Pro9-Dpr10-NH2)] of gonadotropin releasing hormone (GnRH). The molecule was simulated in vacuo at T = 300 K in two conformational states, previously investigated [J. Rizo et al. Journal of the American Chemical Society, (1992) Vol. 114, p. 2860], which differ by the orientation of the N-terminal tail, above (tail up, TU) and below (tail down. TD) the cyclic heptapeptide ring. As in previous applications of the LS method, we have found the following: (1) While FA is a crude approximation for the correct F, results for the difference, ΔFA = FA(TD) – FA(TU) converge rapidly to 5.6(1) kcal/mole as the approximation is improved (i.e., as b and l are increased), which suggests that this is the correct value for ΔF; therefore TD is more stable than TU. (The corresponding difference in entrophy. TΔSA = 1.3(2) kcal/mole, is equal to the value obtained by the harmonic approximation.) (2) The lowest approximation, which has the minimal number of local states, i.e., based on b = 0 (no correlations) and l = 1 (the angle values are distributed homogeneously), also leads to the correct value of ΔF, within the error bars. This is important since the lowest approximation can be applied even to large proteins. (3) The method enables one to define the entropy of a part of the molecule and thus to measure the flexibility of this part. We have verified that the results for T[SA(TU) – SA(TD)] of the tail alone converged to 2.4(1) kcal/mole, which demonstrates the relatively high flexibility of the tail in the TU state. In order to study the random coil state, the Asp4-Dpr10 analogue and its linear version were simulated by MU at 1000 K. We have been able to calculate a lower bound, ∼ 25 kcal/mole for T[S(linear) – S(cyclic)], which is the reduction in the conformational entropy caused by the ring closure. © 1994 John Wiley & Sons, Inc." @default.
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- W2005506293 date "1994-07-01" @default.
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- W2005506293 title "Computer simulation of the free energy of peptides with the local states method: Analogues of gonadotropin releasing hormone in the random coil and stable states" @default.
- W2005506293 cites W1550166367 @default.
- W2005506293 cites W1565826566 @default.
- W2005506293 cites W1625910593 @default.
- W2005506293 cites W1641978920 @default.
- W2005506293 cites W1965433785 @default.
- W2005506293 cites W1965499014 @default.
- W2005506293 cites W1967423835 @default.
- W2005506293 cites W1968192899 @default.
- W2005506293 cites W1971524897 @default.
- W2005506293 cites W1975115411 @default.
- W2005506293 cites W1975832522 @default.
- W2005506293 cites W1976001520 @default.
- W2005506293 cites W1976032956 @default.
- W2005506293 cites W197702477 @default.
- W2005506293 cites W1977334225 @default.
- W2005506293 cites W1977967893 @default.
- W2005506293 cites W1980220562 @default.
- W2005506293 cites W1982582136 @default.
- W2005506293 cites W1984527736 @default.
- W2005506293 cites W1986359945 @default.
- W2005506293 cites W1986982278 @default.
- W2005506293 cites W1989469163 @default.
- W2005506293 cites W1993177346 @default.
- W2005506293 cites W1999318493 @default.
- W2005506293 cites W1999431967 @default.
- W2005506293 cites W1999465809 @default.
- W2005506293 cites W2002268576 @default.
- W2005506293 cites W2003845868 @default.
- W2005506293 cites W2007458524 @default.
- W2005506293 cites W2009333758 @default.
- W2005506293 cites W2009922768 @default.
- W2005506293 cites W2014244970 @default.
- W2005506293 cites W2014428336 @default.
- W2005506293 cites W2018619831 @default.
- W2005506293 cites W2019476648 @default.
- W2005506293 cites W2022102534 @default.
- W2005506293 cites W2027924076 @default.
- W2005506293 cites W2028099075 @default.
- W2005506293 cites W2030320751 @default.
- W2005506293 cites W2033350048 @default.
- W2005506293 cites W2034460790 @default.
- W2005506293 cites W2035312836 @default.
- W2005506293 cites W2037360677 @default.
- W2005506293 cites W2038917819 @default.
- W2005506293 cites W2042415727 @default.
- W2005506293 cites W2044055096 @default.
- W2005506293 cites W2044238309 @default.
- W2005506293 cites W2047654573 @default.
- W2005506293 cites W2050932331 @default.
- W2005506293 cites W2051082589 @default.
- W2005506293 cites W2056760934 @default.
- W2005506293 cites W2056892236 @default.
- W2005506293 cites W2060130346 @default.
- W2005506293 cites W2067574878 @default.
- W2005506293 cites W2075468840 @default.
- W2005506293 cites W2077083927 @default.
- W2005506293 cites W2079199763 @default.
- W2005506293 cites W2081134479 @default.
- W2005506293 cites W2100816704 @default.
- W2005506293 cites W2102697248 @default.
- W2005506293 cites W2131404542 @default.
- W2005506293 cites W2140151763 @default.
- W2005506293 cites W2323178299 @default.
- W2005506293 cites W2953311884 @default.
- W2005506293 cites W3004675605 @default.
- W2005506293 cites W4206038828 @default.
- W2005506293 cites W4230106050 @default.
- W2005506293 cites W4376849580 @default.
- W2005506293 doi "https://doi.org/10.1002/bip.360340703" @default.
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