Outline Introduction : computational method used Paper discussion Biotechnological applications

Computational design of receptor and sensor proteins with novel functions Nature vol..423 May 8 2003, pp.:185-190

Designed a computational method: identify amino acid sequences predicted to form a complimentary surface between the protein and a target ligand replacing the wild type ligand

To test their method they chose E.coli. Periplasmic binding protein (PBP): glucose binding protein (GBP) ribose binding protein (RBP) arabinose binding protein (ABP) glutamine binding protein (QBP) histidine binding protein (HBP)

To explore critical parameters of molecular recognition: Target ligands bear little resemblance to wild type and chemically different from each other. To explore critical parameters of molecular recognition: molecular shape, chirality, functional groups, internal flexibility,charge, and water solubility.

How were they able to know if there is binding of the ligand ? Introducing fluorophores at residues that exhibit changes in fluorescence emission due to changes in conformation (open vs close)

Test it in cells RBP and GBP involved in signal transduction pathways at the gene levels presence of ligand to the above mentioned receptors will cause the upregulation of b-galactosidase gene expression. The RBP and GBP were replaced with the designed TNT and L-lactate receptors and tested using this expression mechanism .

Biotechnological applications Developing specific cell based detectors for chemical threats and pollutants: TNT is carcinogen and explosive, having bacteria with TNT.R3 that respond with the expression of a fluorescent gene Products such as drugs needs to be highly purified and with receptors being able to differentiate between chiral (L-lactate) compounds pharmaceutical companies will be able to achieve this goal