Date of Award


Publication Type

Doctoral Thesis

Degree Name



Chemistry and Biochemistry

First Advisor

Mutus, Bulent


gasotransmitter, hydrogen sulfide, nitric oxide



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


The discovery of nitric oxide (NO), a toxic gas, as a gasotransmitter produced by mammalian cells has generated interest in other gases that may act as signaling molecules. One of those gases is hydrogen sulfide (H2S), produced by the transsulfuration enzymes CBS and CSE, which has been postulated to be a gasotransmitter like NO. We developed a microplate-based colourimetric assay for free H2S gas. Solutions of dissolved H2S spontaneously release gaseous H2S. In our assay gaseous H2S is released from solution, and reacts with silver embedded on the underside of a microplate cover, forming Ag2S, which can be quantified by absorbance. Using this assay the kinetic parameters of CSE were measured, as was H2S production from mouse liver homogenates. H2S has been postulated to signal through modification of cysteine residues on proteins (S-sulfuration), and the first protein shown to be S-sulfurated was GAPDH.