Fourth Year Student, 2015-2016
Year Matriculated: 2012
Email address: email@example.com
Education: The University of Texas at El Paso; BS in Clinical Laboratory Science
Advisor: Daniel Kim-Shapiro, PhD
Research Interests: Separately, nitric oxide (NO) and H2S have clinical significance and application, and may have yet untold significance in signalling and NO trafficking. However, their interaction, and the possibly beneficial products thereof, is not understood well enough to harness for clinical application. I am interested in characterizing the interaction(s) of nitrite (NO2-) or nitrosylated proteins and acid labile H2S or thiol-containing proteins and exploring the therapeutic potential of possible products.
Recipient of the Young Investigator Award at the 22nd Annual Meeting for the Society for Free Radical Biology and Medicine. The tile of my poster was, “Reactions of Nitrosopersulfide with Heme Proteins”.
To evaluate the bioavailability of NO, one must consider its interaction with other gaseous molecules such as hydrogen sulfide (H2S). When NO or NO+ react with excess H2S they form several intermediates including a stable NO donating intermediate, nitrosopersulfide (SSNO-). The abundance and prominence of iron-containing proteins throughout the human body brings additional relevance to the interaction of ferrous- and ferric-iron containing proteins with SSNO-. Study of the reactions of SSNO- with heme proteins can also provide information about the stability and spontaneous reactivity of this species. We have used electron paramagnetic resonance and UV-Vis spectroscopy to study the reactions of SSNO- with heme proteins. Iron-nitrosyl hemoglobin (HbNO) is formed when SSNO- is reacted with deoxyhemoglobin(dHb) and deoxy methemoglobin, suggesting NO formaton from SSNO-. When SSNO- is reacted with oxygenated hemoglobin, no methemoglobin (metHb) is formed. Taken together, these data confirm release of NO. However, the yields of HbNO in reactions of SSNO- with dHb in these experiments are much less than when SSNO- is reacted with metHb. These data suggest that the ferric iron in metHb potentiates SSNO- reactivity. Furthermore, the absence of methemoglobin formation from reactions of SSNO- and oxyHb, the diminished HbNO yield from metHb and SSNO- under O2, and the presence of MbNO from reactions of metMb and SSNO- under N2, but not from NO donor suggest a vacant heme is required to obtain nitrosyl species, which suggests a direct reaction between the SSNO- and heme.
Abstract entitled "Exploring the effects
of sulfide on nitric oxide bioavailability" accepted as poster and oral presentation at the Nitric Oxide Society's Nitrite/Nitrate conference, June 2014, in Cleveland, OH.
Clodfelter, WH, Basu S, Bolden C, Dos Santos PD, King SB, Kim-Shapiro D. (2015) The relationship between plasma and salivary NOx. Nitric Oxide. 47:85-90.