Abstract
Plant nonspecific lipid transfer proteins (nsLTPs) are small and positively charged proteins. This class of protein is notable for the ability to transfer lipid molecules in vitro. NsLTPs can be further divided into two subclasses according to their molecular weight, namely nsLTP1 (~9 kDa) and nsLTP2 (~7 kDa). Structures of nsLTPs in atomic resolution revealed that a hydrophobic cavity, either embedded in the interior or existed as a tunnel, can be found in this class of proteins. Structures of nsLTPs with one or two lipid molecules bound to the hydrophobic cavity were also solved to atomic resolution. Most understanding about the structural properties of plant nsLTPs were based on these static images. However, due to the fact that molecular recognition is a dynamical process and the binding of lipid molecules may also affect the dynamical behavior of nsLTPs. The techniques of molecular dynamics simulation are very suitable for the investigation of lipid-binding induced behavior changes. Through the molecular dynamics simulations and the following analyses, the conformational space of nsLTPs was sampled and the dynamical properties of the proteins were elaborated. More specifically, the effects of lipid molecule binding were also investigated by free energy calculation. The MD simulations thus provide insight into the structural dynamics which were difficult to achieve by other experimental procedures.