Electronic structure and physicochemical properties of the anti-inflammatory pentapeptide produced by Entamoeba histolytica: A theoretical study

The influence of electron donor and electron acceptor groups on the electronic structure of the anti‐inflammatory tripeptide Cys‐Asn‐Ser

“…1). Studies carried out in other peptides and biological molecules that possess aminoacyl groups have shown that a smaller DE value is evidence of a more acidic group [7,10,21,22]. In Table I, we have reported values for the deprotonation energies for the CNS tripeptide and their derivatives at the B3LYP/6-311þG(2d,2p)// B3LYP/6-311þG(d,p) level of theory, whereas it may be observed that the bond (N1AH2) of the CNS peptide possesses a smaller value for DE with respect to their derivatives that possess electron donor groups, and larger values when compared with the peptides possessing electron withdrawing substituent groups [see Figs.…”

“…These studies allowed finding that MLIF and pMLIF pentapeptides maintained a great structural similarity, particularly among the last three amino acids, CysAsn-Ser (CNS), see Figure 1. At the same time, Morales-Martínez et al [11] carried out experimental studies in in vivo and in vitro models on the novel CNS tripeptide's anti-inflammatory activity with >95% purity and synthesized by the American Peptide Company; they found that the CNS tripeptide's maintained 100% of its biological and anti-inflammatory properties, similar to the MLIF; thus, experimentally verifying the pharmacophore group's anti-inflammatory activity proposed in the MLIF molecule predicted theoretically [10]. Recently, Barrientos-Salcedo et al [12] carried out calculations using second-order Møl-ler-Plesset perturbation theory (MP2) and density functional theory (DFT) theoretical levels to characterize with detail the electronic structure, physicochemical properties, and geometric parameters utilizing standard and complementary density descriptors of the CNS tripeptide.…”

“…These authors established that the same synthetic sequence possesses similar anti-inflammatory properties to those of native MLIF [9], whereas another analogous pentapeptide, that is, the proline amino acid, which was substituted with glutamine in the second position (Met-Pro-Cys-Asn-Ser, pMLIF), presented anti-inflammatory activity; however, another pentapeptide with the same amino acids but a different arrangement (Gln-Cys-Met-SerAsn, sMLIF) did not present anti-inflammatory activity. In early works, we have described the electronic structure and the physicochemical properties of the pentapeptides [10]. These studies allowed finding that MLIF and pMLIF pentapeptides maintained a great structural similarity, particularly among the last three amino acids, CysAsn-Ser (CNS), see Figure 1.…”

Effect of Monocyte Locomotion Inhibitory Factor (MLIF) on the Activation and Production of Intracellular Cytokine and Chemokine Receptors in Human T CD4+ Lymphocytes Measured by Flow Cytometry

“…The observed effects of MLIF could be attributed to the chemical activity of the peptide. Ongoing studies in quantum chemistry have revealed that a pharmacophore group in the MLIF sequence, Cys-Asn-Ser, could be responsible for most of the anti-inflammatory properties of the molecule (Soriano-Correa et al, 2006) Figure 1.…”

Effect of the Monocyte Locomotion Inhibitory Factor (MLIF) a Natural Anti-Inflammatory Produced by E. Histolytica on Apoptosis in Human CD4 + T Lymphocytes

“…This anti-inflammatory effect could be attributed to the chemical activity of the peptide. Ongoing studies in quantum chemistry have revealed that a pharmacophore group in the MLIF sequence (… Cys-AsnSer) could be responsible for most of the anti-inflammatory properties of this molecule [17]. Currently it is unknown whether MLIF may have some involvement with the mechanisms of programmed cell death.…”