Abstract:
:Nonequilibrium molecular dynamics (NEMD) computer simulations are used to calculated the bulk modulus for a dimyristoylphosphatidylcholine bilayer. A methodology is developed whereby NEMD can be effectively used to calculate material properties for complex systems that undergo long time-scale conformational changes. It is found that the bulk modulus upon expansion from a zero stress state agrees well with experimental estimates. However, it is also found that the modulus upon contraction from a zero stress state is larger. From a molecular perspective, it is possible to explain this phenomena by examining the molecular origins of the pressure response. The finding that the two moduli are not equal upon compression and expansion is in apparent contradiction to osmotic stress experiments where the area modulus was found to be the same upon expansion and contraction. This issue is addressed.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Ayton G,Smondyrev AM,Bardenhagen SG,McMurtry P,Voth GAdoi
10.1016/S0006-3495(02)75479-9subject
Has Abstractpub_date
2002-03-01 00:00:00pages
1226-38issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(02)75479-9journal_volume
82pub_type
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