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Original Research Article
Proteomic Analysis of
Bacterial Expression Profiles Following Exposure to
Organic Solvent Flower Extract of Melastoma candidum
D Don (Melastomataceae)
Fai-Chu Wong1,2*,
Ann-Li Yong2, Kooi-Mow Sim1,2,
Hean-Chooi Ong3 and Tsun-Thai Chai1,2
1Centre for Biodiversity
Research, 2Department of Chemical Science,
Faculty of Science, Universiti Tunku Abdul Rahman, 31900
Kampar, 3Institute of Biological Sciences,
Faculty of Science, University of Malaya, 50603 Kuala
Lumpur, Malaysia
*For correspondence:
Email:
wongfc@utar.edu.my
Received: 31 January 2014
Revised accepted: 26 May
2014
Tropical
Journal of Pharmaceutical Research, July 2014;
13(7): 1085-1092
http://dx.doi.org/10.4314/tjpr.v13i7.11
Abstract
Purpose: To
identify potential antibacterial protein targets
following exposure to Melastoma candidum extract.
Methods:
Plant extracts were prepared using sequential extraction
method. Denaturing gel electrophoresis and MALDI TOF-TOF
MS protein sequencing were used to identify
differential-expressed bacterial proteins. 96-well
microplate method was used to determine the minimum
inhibitory concentration (MIC) values. Thin layer
chromatography (TLC) bio-autobiography and
gas-chromatography-mass spectrometry (GC-MS) were
performed to determine the phytochemicals in the active
fraction.
Results: Five differentially expressed
bacterial proteins (four from Escherichia coli and one
from Staphylococcus aureus), were identified via
proteomic approach. Among the bacterial proteins
identified, glutamate decarboxylase, elongation factor-Tu
and α-hemolysin are especially noteworthy, as they are
implicated in critical bacterial pathways pertaining to
survival in acidic environment, protein translation and
virulence, respectively. Additionally, we tested and
reported the minimum inhibition concentrations of
different M. candidum fractions and gas
chromatography-mass spectrometry GC-MS analysis of the
active fraction.
Conclusion: Glutamate decarboxylase, elongation factor-Tu
and α-hemolysin represent potential antibacterial
targets.
Keywords: Escherichia coli, Staphylococcus aureus,
Melastoma candidum, Glutamate decarboxylase, Elongation
factor-Tu, α-Hemolysin, Protein expression |