Heme-based sensors

Biochemistry 8. Gilles-Gonzalez, M. A., and Gonzalez, G. (2005) Heme-based sensors defining characteristics, recent developments, and regulatory hypotheses, J. Inorg. Biochem. 99, 1-22. 

DevS Oxygen heme-based sensor from M. tuberculosis... 

Fig. 5.8 Scheme for heme-based sensors and their biological roles... 

Sousa, E.H.S., Tuckerman, J.R., Gonzalez, G., Gilles-Gonzalez, M.A. A memory of oxygen binding explains the dose response of the heme-based sensor FixL. Biochemistry 46, 6249-6257 (2007). doi 10.1021/bi7003334... 

Gilles-Gonzalez MA, Gonzalez G, Perutz MF. Heme-based sensors, exemplified by the kinas FixL, are a new class of heme protein with distinctive ligand binding and autoxidation. Biochemistry 1994 33 8067-8073. 

Gilles-Gonzalez, M. A. Gonzalez, G. A surfeit of heme-based sensors. In The Smallest Biomolecules Diatomics and Their Interactions with Heme Proteins, Ghosh, A. (ed.), Elsevier, Amsterdam, 2008. 

Myriad metalloproteins bind iron-protoporphyrin IX, known as heme (Fig. 15). Heme protein properties are determined by a variety of factors within the inner coordination sphere and without. These include chemical modifications to the porphyrin macrocycle, different axial ligation, perturbations to conformation, and protein dynamics surrounding the cofactor. Because of the extensive proliferation of heme proteins, we will limit ourselves to a small subset. These will include the cytochromes c, myoglobins, heme oxygenases and peroxidases, and a heme-based chemical sensor. 

Moskvin, O.V., Kaplan, S., Gilles-Gonzalez, M.A., Gomelsky, M. Novel heme-based oxygen sensor with a revealing evolutionary history. J. Biol. Chem. 282, 28740-28748 (2007). doi 10.1074/jbc.M703261200... 

III. Overview of Heme-Based O2 Sensors Having a Heme-Binding PAS Domain... 

Tuckerman JR, Gonzalez G, Dioum EM, Gilles-Gonzalez MA. Ligand and oxidation-state specific regulation of the heme-based oxygen sensor FixL fi om Sinorhizobium meliloti. Biochemistry. Biochemistry 2002 41 6170-6177. 

The reaction of peroxide with ferrous heme iron is the basis of electrocatalytic peroxide sensors. A selection that gives a representative overview of the biomolecules and transducers is included in Table 2.5. Peroxidase, catalase, haemoglobin, cytochrome c, microperoxidase and hemin can all be explored for peroxide measurement. Most papers on DET-based biosensor are related to peroxide detection in a variety of environments with peroxidases. 

Sensors for inhibitors are based on competitive inhibition between a substrate and an inhibitor for an enzyme binding site, inhibition of an enzyme reaction by product accumulation, irreversible binding of an inhibitor to an active binding site, or redox-active heme or SH groups of enzymes that lead to the blocking of enzyme activity. 

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