Enzymes and proteins from extremophiles as hyperstable probes in nanotechnology: the use of D-trehalose/D-maltose-binding protein from the hyperthermophilic archaeon Thermococcus litoralis for sugars monitoring

The D-trehalose/D-maltose-binding protein(TMBP), a monomeric protein of 48 kDa, is onecomponent of the trehalose and maltose (Mal) uptakesystem. In the hyperthermophilic archaeon Thermococcuslitoralis, this is mediated by a protein-dependentATP-binding cassette system transporter. The genecoding for a thermostable TMBP from the archaeon T.litoralis has been cloned, and the recombinant proteinhas been expressed in E. coli. The recombinant TMBPhas been purified to homogeneity and characterized. Itexhibits the same functional and structural propertiesas the native one. In fact, it is highly thermostable andbinds sugars, such as maltose, trehalose and glucose,with high affinity. In this work, we have immobilizedTMBP on a porous silicon wafer. The immobilizationof TMBP to the chip was monitored by reflectivity andFourier Transformed Infrared spectroscopy. Furthermore,we have tested the optical response of the protein-Chip complex to glucose binding. The obtained data suggest the use of this protein for the design ofadvanced optical non-consuming analyte biosensors forglucose detection.