Abstract:
The DBL2β-PfEMP1 is an adhesive domain of
Plasmodium falciparum, which is important for
malaria pathogenesis. In this study, the DBL2βPfEMP1
from
the Indonesian
isolate of Plasmodium
falciparum
was
cloned and the
protein structure
prediction
of
the DBL2β
recombinant
protein as
well
as its
ligand
binding sites was
carried
out.
The
DBL2β
recombinant
protein consists of 1674
nucleotides
which are translated into 558 amino
acids.
Analysis
using Expasy
ProtParam tool showed
that
the protein
had a MW
of 64.69
kDa
with an
isoelectric
point
of 8.82.
It had 83 negatively
charged
residues
(Asp +
Glu)
and 98 positively
charged
residues (Arg + Lys).
It was classified as
an
unstable protein because it had an instability
index
of 40.01.
Protein structure prediction of the
DBL2β
recombinant
protein and its
binding
sites
was
carried out using
the
I-TASSER
program.
It
showed
that the DBL2β
recombinant
protein
had
the
highest significant alignment
with
the DBLβ domain of PF11_0521 PfEMP1, which is bound
to the human ICAM-1, but the protein had the
closest structural similarity with the of EBA-175
Region II (RII) of P. falciparum, where the protein
functions as the cell invasion molecule. The highest
C-score of ligand-binding site was 0.10 for the
PEPTIDE ligand (GLN, LEU, ASP, PHE, GLU,
ASP, VAL, TRP, ASN, SER, SER, TYR), and the ligand-binding site residues were at 84, 87, 88, 91,
92, 95, 99, 196, 199, 200, 203, 206. It is likely
that the DBL2β recombinant protein has the major
function as an adhesion molecule for invasion to
the host. Further studies on its role in in vivo models
are needed to develop a definite conclusion.
