Alisa B Rupenyan

  • Citations Per Year
Learn More
Phytochromes are red-light photoreceptor proteins that regulate a variety of responses and cellular processes in plants, bacteria, and fungi. The phytochrome light activation mechanism involves isomerization around the C(15)═C(16) double bond of an open-chain tetrapyrrole chromophore, resulting in a flip of its D-ring. In an important recent development,(More)
Protonated dialanine cations have been isolated in a Fourier transform ion cyclotron resonance mass-spectrometer (FT-ICR-MS) and subjected to infrared multiphoton dissociation (IRMPD) at the free electron laser facility CLIO in Orsay (France). The spectral dependence of the IR induced fragmentation pattern in the mid-infrared region (800-2000 cm -1 ) is(More)
Proteorhodopsin (pR) is a membrane-embedded proton pump from the microbial rhodopsin family. Light absorption by its retinal chromophore initiates a photocycle, driven by trans/cis isomerization on the femtosecond to picosecond time scales. Here, we report a study on the photoisomerization dynamics of the retinal chromophore of pR, using dispersed ultrafast(More)
Salt bridges play an important role in protein folding and in supramolecular chemistry, but they are difficult to detect and characterize in solution. Here, we investigate salt bridges between glutamate (Glu(-)) and arginine (Arg(+)) using two-dimensional infrared (2D-IR) spectroscopy. The 2D-IR spectrum of a salt-bridged dimer shows cross peaks between the(More)
In proteins and enzymes, the local environment of an active cofactor plays an important role in controlling the outcome of a functional reaction. In photoactive yellow protein (PYP), it ensures photoisomerization of the chromophore, a prerequisite for formation of a signaling state. PYP is the prototype of a PAS domain, and the preferred model system for(More)
Proteorhodopsin is an ion-translocating member of the microbial rhodopsin family. Light absorption by its retinal chromophore initiates a photocycle, driven by trans/cis isomerization, leading to transmembrane translocation of a proton toward the extracellular side of the cytoplasmic membrane. Here we report a study on the photoisomerization dynamics of the(More)
Cytochrome P450BM3 is a bacterial enzyme with a heme cofactor that binds small diatomic ligands. Here we report the first study of carbon monoxide (CO) photodissociation and rebinding in ferrous P450BM3 on an ultrafast time scale. We monitored dissociation of carbon monoxide upon Soret band excitation using visible and infrared femtosecond spectroscopy(More)
  • 1