Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 211.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 245.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Warning: imagejpeg(C:\Inetpub\vhosts\kidney.de\httpdocs\phplern\14754182
.jpg): Failed to open stream: No such file or directory in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 117 Phys+Rev+E+Stat+Nonlin+Soft+Matter+Phys
2003 ; 68
(6 Pt 1
): 061109
Nephropedia Template TP
gab.com Text
Twit Text FOAVip
Twit Text #
English Wikipedia
Network rigidity at finite temperature: relationships between thermodynamic
stability, the nonadditivity of entropy, and cooperativity in molecular systems
#MMPMID14754182
Jacobs DJ
; Dallakyan S
; Wood GG
; Heckathorne A
Phys Rev E Stat Nonlin Soft Matter Phys
2003[Dec]; 68
(6 Pt 1
): 061109
PMID14754182
show ga
A statistical mechanical distance constraint model (DCM) is presented that
explicitly accounts for network rigidity among constraints present within a
system. Constraints are characterized by local microscopic free-energy functions.
Topological rearrangements of thermally fluctuating constraints are permitted.
The partition function is obtained by combining microscopic free energies of
individual constraints using network rigidity as an underlying long-range
mechanical interaction, giving a quantitative explanation for the nonadditivity
in component entropies exhibited in molecular systems. Two exactly solved
two-dimensional toy models representing flexible molecules that can undergo
conformational change are presented to elucidate concepts, and to outline a DCM
calculation scheme applicable to many types of physical systems. It is proposed
that network rigidity plays a central role in balancing the energetic and
entropic contributions to the free energy of biopolymers, such as proteins. As a
demonstration, the distance constraint model is solved exactly for the
alpha-helix to coil transition in homogeneous peptides. Temperature and size
independent model parameters are fitted to Monte Carlo simulation data, which
includes peptides of length 10 for gas phase, and lengths 10, 15, 20, and 30 in
water. The DCM is compared to the Lifson-Roig model. It is found that network
rigidity provides a mechanism for cooperativity in molecular structures including
their ability to spontaneously self-organize. In particular, the formation of a
characteristic topological arrangement of constraints is associated with the most
probable microstates changing under different thermodynamic conditions.