Tuning gas binding in heme proteins — ASN Events
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  2. Session Seven - Poster Session B includes Happy Hour & Trade Display
  3. Tuning gas binding in heme proteins

Tuning gas binding in heme proteins (#241)

Trevor D Rapson 1 , Shouvik Aditya 1 , Helen Dacres 1 , Stephen C Trowell 1
  1. CSIRO, Canberra, ACT, Australia

The gas binding properties of heme proteins makes them attractive biotechnological tools.1 In this project we are developing proteins which can discriminate between oxygen and other diatomic gases for sensing applications.

The Heme-Nitric oxide/OXygen binding (H-NOX) proteins are a family of proteins where the gas binding properties of the heme group can be tightly controlled.  Studies carried out by Marletta and co-workers have highlighted the importance of distal tyrosine residues in controlling the specificity for either oxygen or nitric oxide.2 

The chemistry catalyzed by hemoproteins is in large part directed by the heme cofactor.  It is relatively easy to remove the native heme groups and substitute a synthetic porphyrin.3 Therefore the heme group is a second possible site of chemical modification.

In this project, the gas binding properties of an H-NOX protein, guanylate cyclase (GCY-35) from Caenorhabditis elegans4 are investigated.  The ability to tune nitric oxide and oxygen binding through changing both the heme metal centers and the amino acid scaffold surrounding the heme cofactor will be determined in order to improve our understanding of ligand specificity in H-NOX proteins and investigate whether the proteins could be used in novel gas sensors.

  1. Winter, M. B.; McLaurin, E. J.; Reece, S. Y.; Olea, C.; Nocera, D. G.; Marletta, M. A. JACS 2010, 132, 5582.
  2. Boon, E. M.; Marletta, M. A. Journal of Inorganic Biochemistry 2005, 99, 892.
  3. Ascoli, F.; Fanelli, M. R. R.; Antonini, E. Methods in Enzymology 1981, 76, 72.
  4. Gray, J. M.; Karow, D. S.; Lu, H.; Chang, A. J.; Chang, J. S.; Ellis, R. E.; Marletta, M. A.; Bargmann, C. I. Nature 2004, 430, 317.