I have an expertise in producing the recombinant proteins and my research interests focus on the viral enzymes including nonstructural protein 5 (NS5) of Dengue and Zika virus and the protease domain of nsP2 Chikungunya virus. Once the virus infects into the host cell, it can insert its genetic material into the host, literally hijacking the host cell machinery for producing its own proteins. The Dengue and Zika viral genome is a positive single-strand RNA with 5-methyl cap but no poly (A) tail. This 5 RNA cap is critical for efficient viral polyprotein translation by protecting mRNA from degradation. The two main functions of NS5 are the guanylyltransferase and methyltransferase activities that are essential for forming RNA cap structure. Recently, NS5 protein became one of the main targets to disrupt viral proliferation. The hypothesis is that if the RNA is not capped, it will be degraded and protein translation will not occur, disabling the virus from replicating and stopping infection. Likewise for the nsP2, a long viral polyprotein has to be cleaved into single protein by the protease enzyme activity. Since these viral proteins are so important enzymes, we therefore focus on their enzyme activities by using the recombinant protein as a tool.

1.Saisawang C, Kuadkitkan A, Auewarakul P, Smith DR, Ketterman AJ. Glutathionylation of dengue and Zika NS5 proteins affects guanylyltransferase and RNA dependent RNA polymerase activities. PLoS One. 2018;13(2):e0193133.

2.Saisawang C, Kuadkitkan A, Smith DR, Ubol S, Ketterman AJ. Glutathionylation of chikungunya nsP2 protein affects protease activity. Biochim Biophys Acta Gen Subj. 2017;1861(2):106-11.

3.Kovanich D, Saisawang C, Sittipaisankul P, Ramphan S, Kalpongnukul N, Somparn P, et al. Analysis of the Zika and Japanese Encephalitis Virus NS5 Interactomes. J Proteome Res. 2019;18(8):3203-18.

4.Ketterman AJ, Wongtrakul J, Saisawang C. Phytochemical andrographolide modulates NF-B and JNK in human neuroblastoma SH-SY5Y cells, a cell model for Parkinson’s disease. Heliyon. 2020;6(6):e04121.

5.Saisawang C, Wongsantichon J, Robinson RC, Ketterman AJ. Glutathione transferase Omega 1-1 (GSTO1-1) modulates Akt and MEK1/2 signaling in human neuroblastoma cell SH-SY5Y. Proteins. 2019;87(7):588-95.