Mechanical unfolding of titin I27 domain: Nanoscale simulation of

The mechanical properties of a single titin immunoglobulin-like domain (i27) are studied,based on the virial stress definition, via steered molecular dynamics simulation. moreover, the effects ofbiological conditions on the obtained results are investigated. due to different viewpoints on virial stressdefinition, the role of kinetic stress in virial stress definition is elucidated. the obtained young's modulusis about 0:70:1 gpa. it is found that the ultimate stress decreases nonlinearly and the young's modulusdecreases almost linearly with an increase in temperature. it is observed that the mechanical propertiesdecrease with a decrease in the strain rate. the mechanical properties are not sensitive to small unfoldingforces, but they rise up with an increase in the force magnitude afterwards. considering the kinetic stressterm in calculation of virial stress increases the accuracy of the results, but does not have a significanteffect on mechanical properties, especially at low temperatures. this implies that the kinetic stress termcan be ignored at low temperatures. this study furnishes a basis for the i27 domain, where mechanicalproperties must be taken into account.