Structure-function studies of BPP-BrachyNH2 and synthetic analogues thereof with Angiotensin I-Converting Enzyme

Abstract

The vasoactive proline-rich oligopeptide termed BPP-BrachyNH (H-WPPPKVSP-NH) induces in vitro inhibitory activity of angiotensin I-converting enzyme (ACE) in rat blood serum. In the present study, the removal of N-terminal tryptophan or C-terminal proline from BPP-BrachyNH was investigated in order to predict which structural components are important or required for interaction with ACE. Furthermore, the toxicological profile was assessed by in silico prediction and in vitro MTT assay. Two BPP-BrachyNH analogues (des-Trp-BPP-BrachyNH and des-Pro-BPP-BrachyNH) were synthesized, and in vitro and in silico ACE inhibitory activity and toxicological profile were assessed. The des-Trp-BPP-BrachyNH and des-Pro-BPP-BrachyNH were respectively 3.2- and 29.5-fold less active than the BPP-BrachyNH-induced ACE inhibitory activity. Molecular Dynamic and Molecular Mechanics Poisson-Boltzmann Surface Area simulations (MM-PBSA) demonstrated that the ACE/BBP-BrachyNH complex showed lower binding and van der Wall energies than the ACE/des-Pro-BPP-BrachyNH complex, therefore having better stability. The removal of the N-terminal tryptophan increased the in silico predicted toxicological effects and cytotoxicity when compared with BPP-BrachyNH or des-Pro-BPP-BrachyNH. Otherwise, des-Pro-BPP-BrachyNH was 190-fold less cytotoxic than BPP-BrachyNH. Thus, the removal of C-terminal proline residue was able to markedly decrease both the BPP-BrachyNH-induced ACE inhibitory and cytotoxic effects assessed by in vitro and in silico approaches. In conclusion, the aminoacid sequence of BPP-BrachyNH is essential for its ACE inhibitory activity and associated with an acceptable toxicological profile. The perspective of the interactions of BPP-BrachyNH with ACE found in the present study can be used for development of drugs with differential therapeutic profile than current ACE inhibitors.

Constituents of buriti oil (Mauritia flexuosa L.) like inhibitors of the SARS-Coronavirus main peptidase: an investigation by docking and molecular dynamics

“…The simulations were performed for 30 ns using a 2fs integration time step (Ramos et al, 2012). Each system was heated in gradual increments at the following temperatures: 100 K (10ps), 150 K (5ps), 200 K (5ps) and 250 K (5ps) and, after these steps, the temperature was adjusted to 310 K (Arcanjo et al, 2017). The interaction energies of Coulomb (Coul), Lennard-Jones (LJ) and the sum of Coul þ LJ were calculated to analyze the interactions between protein-ligand (Lemkul, 2019).…”

Antiviral potential of diminazene aceturate against SARS-CoV-2 proteases using computational and in vitro approaches

“…The MD simulations of the complexes selected after molecular docking (Spike_Dize) were performed using GROMACS 2018.1 software [ 35 , 36 ] following Arcanjo and collaborators [ 37 ]. Spike glycoprotein (S glycoprotein) model, code P0DTC2, was used from the SWISS-MODEL server [ 38 ].…”

In silico study of the interactions of Pilocarpus microphyllus imidazolic alkaloids with the main protease (Mpro) of SARS-CoV-2

“…The molecular dynamics simulations were performed with the GROMOS96 force field 53a6 included in the GROMACS package, version 2018.1 [55,56]. The systems were simulated using the NPT set (in which the number of particles, pressure, and temperature are constant), and periodic boundary conditions (cubic) [57]. The water molecules during the process were made explicit by the Single Point Charge (SPC) model [58].…”

“…The simulation time was 50 nanoseconds (ns), with an integration step of 2 fs [59]. The systems were gradually warmed up, starting with 100 K (10 ps), 150 K (5 ps), 200 K (5 ps), 250 K (5 ps), and later being adjusted to 310 K [57]. The initial 6 ns of each simulation were considered as part of the heating (0.025 ns) and equilibrium (5.975 ns) steps, not being used in the data analysis [57].…”

“…The temperatures of solvent and solutes (protein, ligands, water, and sodium ions) were independently coupled to a thermal bath with a relaxation time of 0.1 ps using the V-rescale thermostat [57]. The pressure in the system was weakly coupled to a pressure bath with 2 ps of relaxation time, using the Parrinello-Rahman barostat [60,61].…”