Computational design and biochemical characterization of maize nonspecific lipid transfer protein variants for biosensor applications.

Lipid transfer proteins (LTPs) are a family of proteins that bind and transfer lipids. Utilizing the maize LTP, we have successfully engineered fluorescent reagentless biosensors for the natural ligand of LTPs; this was achieved by using computational protein design to remove a disulfide bridge and attaching a thio-reactive fluorophore. Conformational change induced by ligand titration is thought to affect the fluorescence of the fluorophore, allowing detection of ligand binding. Fluorescence measurements show that our LTP variants have affinity to palmitate that is consistent with wild-type LTP. These molecules have the potential to be utilized as scaffolds to design hydrophobic ligand biosensors or to serve as drug carriers.