The focus of my current research is the discovery and characterization of new tools for the emerging field of optogenetics. In optogenetics, light-triggered molecules from the rhodopsin family are used as “light-switches” to interrogate or control cellular processes. Currently, the only two highly functional “on-off” switches used in the optogenetic manipulation of neurons and cardiomyocites are channelrhodopsin 2 (CrChR2) from the green algae Chlamydomonas reinhardtii, and halorhodpsin (HR) from H. salinarum.  Of particular interest to me, is the use of new rhodopsins in optogenetic applications involving heart cells, ultimately designing light-triggered molecular defibrillators.

One system under investigation is the recently discovered sodium pumping rhodopsin (NaR) from the marine flavobacterium K. eikastus.  This is the first sodium-specific light triggered pump currently known.  We are utilizing a number of different spectroscopic techniques to probe the structural changes that take place upon light activation of NaR.  We want to understand how the structure of NaR has evolved to perform its selective ion pumping mechanism.  We are also applying different spectroscopic modalities to study other channelrhodopsins from Platymonas (PsChr), to understand the structural elements that impart its hyper-activity.  Once we understand the structural constraints that define a good optogenetic tool, we can more easily screen natural systems or engineer new molecules de novo and expand the optogenetic tool set.

Other Interests: When not in the lab I am an avid guitar player and collector with a deep interest in the history of the blues and jazz.  I have been featured in guitar periodicals and played several high profile gigs with local, regional, and international recording artists. 

Publications

  • Metal binding of flavonoids and their distinct inhibition mechanisms toward the oxidation activity of Cu2+-β-amyloid: not just serving as suicide antioxidants! Tay WM, da Silva GF, Ming LJ.  Inorg Chem. 2013 Jan 18;52(2):679-90.  PMID:23301941  Read More
  • Spectroscopic evidence of the role of an axial ligand histidinate in the mechanism of adrenal cytochrome b561. da Silva GF, Shinkarev VP, Kamensky YA, Palmer G.  Biochemistry. 2012 Nov 6;51(44):8730-42. PMID: 23088392  Read More
  • Functional and structural roles of residues in the third extramembrane segment of adrenal cytochrome b561. Liu W, da Silva GF, Wu G, Palmer G, Tsai AL, Kulmacz RJ. Biochemistry. 2011 Apr 19;50(15):3149-60. PMID: 21401125  Read More
  • 1H NMR, mechanism, and mononuclear oxidative activity of the antibiotic metallopeptide bacitracin: the role of D-Glu-4, interaction with pyrophosphate moiety, DNA binding and cleavage, and bioactivity. Tay WM, Epperson JD, da Silva GF, Ming LJ. J Am Chem Soc. 2010 Apr 28;132(16):5652-61. PMID: 20359222  Read More
  • Methionine does not reduce Cu(II)-beta-amyloid!–rectification of the roles of methionine-35 and reducing agents in metal-centered oxidation chemistry of Cu(II)-beta-amyloid. da Silva GF, Lykourinou V, Angerhofer A, Ming LJ. Biochim Biophys Acta. 2009 Jan;1792(1):49-55. PMID: 19061952  Read More
  • His92 and His110 selectively affect different heme centers of adrenal cytochrome b(561). Liu W, Rogge CE, da Silva GF, Shinkarev VP, Tsai AL, Kamensky Y, Palmer G, Kulmacz RJ. Biochim Biophys Acta. 2008 Sep;1777(9):1218-28. PMID: 18501187  Read More

Education

NIH Ruth L. Kirschstein NRSA Postdoctoral Fellow - Rice University, Department of Biochemistry & Cell Biology, Mentor: Dr. Graham Palmer, 2009-2013

Postdoctoral Research Fellow - UTHSC, Internal Medicine Division of Hematology, Mentor: Dr. Richard Kulmacz, 2007-2009

Ph.D in Chemistry - University of South Florida, Mentors: Dr. Li-June Ming and Dr. Brian Livingston, 2002-2007

B.A. in Chemistry - University of South Florida, 1999-2002

Research Interests

Transmembrane Proteins, Transmembrane Ion/Charge Transport, Light Sensors, Optogenetics, Bioenergenetics, Protein Engineering, Catalytic Promiscuity, Evolutionary/Developmental Biology, Biomimetics, Oxidative Stress, Nuclear Magnetic Resonance, Electron Paramagnetic Resonance, Magnetic Circular Dichroism, UV-Vis Spectroscopy, Stopped-Flow Kinetics, Enzymology, Chemical Kinetics