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Note:
Structural Biology 2018 & STD AIDS 2018
Journal of Genetics and Molecular Biology
|
Volume 2
S e p t e m b e r 0 3 - 0 4 , 2 0 1 8 | B a n g k o k , T h a i l a n d
allied
academies
STD-AIDS AND INFECTIOUS DISEASES
STRUCTURAL BIOLOGY AND PROTEOMICS
&
International Conference on
International Conference on
Joint Event on
Jupitara Kalita et al., J Genet Mol Biol 2018, Volume 2
COMPREHENSIVE ANALYSIS OF
THE CATALYTIC AND STRUCTURAL
PROPERTIES OF A MU-CLASS
GLUTATHIONE S-TRANSFERASE FROM
FASCIOLA GIGANTICA
Jupitara Kalita, Rohit Shukla, Harish Shukla
and
Timir Tripathi
North Eastern Hill University, India
G
lutathione S-transferases (GSTs) play an important role in the
detoxification of xenobiotics. They catalyze the nucleophilic addition of
glutathione (GSH) to nonpolar compounds, rendering the products water-
soluble. Fascioliasis is a neglected tropical disease caused by the food-
borne trematodes
Fasciola hepatica
and
Fasciola gigantica
. These parasites
infect mammals through ingestion of aquatic plants or contaminated water
having encysted metacercaria. GST plays important roles in maintaining the
cellular homeostasis, protection against oxidative stress and detoxification
of xenobiotics thereby helping in survival. In the present study, we have
investigated the catalytic and structural properties of a mu-class GST from
the liver
Fasciola gigantica
(FgGST1). This will help in understanding the
structure-function relationship of GSTs in these flukes. The gst1 gene was
amplified, cloned in pET23a vector and overexpressed in BL21(DE3) cells. The
purified recombinant FgGST1 formed a homodimer and composed of ~25
kDa subunit. Kinetic analysis revealed that FgGST1 displays broad substrate
specificity and shows high GSH conjugation activity towards 1-chloro-2,4-
dinitrobenzene, 4-nitroquinoline-1-oxide, trans-4-phenyl-3-butene-2-one and
peroxidase activity towards trans-2-nonenal and hexa-2,4-dienal. The FgGST1
was highly sensitive to inhibition by Cibacron blue. The cofactor(GSH) and
inhibitor(Cibacron blue) were docked against FgGST1 and binding sites were
identified. The molecular dynamics studies and principal component analysis
indicated the stability of the systems and the collective motions, respectively.
Unfolding studies suggest that FgGST1 is a highly cooperative molecule
because, during GdnHCl-induced denaturation, a simultaneous unfolding
of the protein without stabilization of any partially folded intermediate is
observed. The protein is stabilized with a conformational free energy of about
10±0.3 kcal mol−1.
Jupitara Kalita is a PhD student in the Department of
Biochemistry, NEHU, Shillong. She has completed her
MSc in Biochemistry in the year 2014. Her research
interest concerns the structure, function, folding and
stability of GSTs in infectious liver flukes. Her thesis
centers around understanding the structure-function
relationship of GSTs. This includes biochemical and
biophysical characterization of the proteins. Other
than this, she is also working in a project which deals
with interactions of mRNA export factors (proteins)
and nuclear pores.
jupitarakalita@gmail.comBIOGRAPHY