1
Centerfor Advanced Biomaterial for Health Care (CABHC), Istituto Italianodi Tecnologia, I-80125 Naples, Italy;pasqualina.scognamiglio@iit.it
Benzofuran
derivatives are synthetic compounds that are finding an increasing
interest in the scientific community not only as building blocks for
the realization of new materials, but also as potential drugs thanks
to their ability to interact with nucleic acids, interfere with the
amyloid peptide aggregation and cancer cell cycle. However, their
ability to interact with proteins is a theme still in need of
investigation for the therapeutic importance that benzofurans could
have in the modulation of protein-driven processes and for the
possibility of making use of serum albumins as benzofurans delivery
systems. To this scope, we investigated the protein binding ability
of two 4-nitrophenyl functionalized benzofurans previously
synthesized in our laboratory and herein indicated as BF1 and BDF1,
which differed for the number of furan rings (a single moiety in BF1,
two in BDF1), using bovine serum albumin (BSA) as model protein. By
circular dichroism (CD) spectroscopy we demonstrated the ability of
the two heteroaromatic compounds to alter the secondary structure of
the serum albumin leading to different consequences in terms of BSA
thermal stability with respect to the unbound protein (ΔT
m
>
3°C
for BF1, -0.8°C for BDF1 with respect to unbound BSA, in PBS buffer,
pH 7.5) as revealed in our CD melting studies. Moreover, a molecular
docking study allowed us to compare the possible ligand binding modes
of the mono and difuranic derivatives showing that while BF1 is
preferentially housed in the interior of protein structure, BDF1 is
predicted to bind the albumin surface with a lower affinity than BF1.
Interestingly, the different affinity for the protein target
predicted computationally was confirmed also experimentally by
fluorescence spectroscopy (k
D
= 142.4 ± 64.6 nM for BDF1
vs. 28.4 ± 10.1 nM for BF1). Overall, the above findings suggest the
ability of benzofurans to bind serum albumins that could act as their
carriers in drug delivery applications.