Comparative study on structural, biological and functional activities of hydrolysates from Adzuki bean (Vigna angularis) and mung bean (Vigna radiata) protein concentrates using Alcalase and Flavourzyme.

The physicochemical features of mung bean protein (MBP) and adzuki bean protein (ABP) hydrolysates derived from Alcalase (MBPHA, ABPHA) and Flavourzyme (MBPHF, ABPHF) were assessed using FTIR, hydrophobicity, emulsion activity, zeta potential, and health-promoting activities. The results proved that the choice of peptidase and substrate both have a significant effect on the hydrolysates in different physicochemical, structural and functional properties. Size exclusion-HPLC was used to fractionate the MBP and ABP hydrolysates. The results demonstrated that Alcalase hydrolysates included smaller peptides than Flavourzyme hydrolysates, and the chromatogram patterns of the two peptidases were similar. The peptides with the most potent antioxidant and ACE-inhibitory properties were identified using MALDI-TOF-MS. The fraction (F4) of MBPHA exhibited the highest levels of metal chelating activity. The Flavourzyme hydrolysates fraction (F2) and the ABPHA fraction (F2) showed the highest ABTS radical scavenging activity and ACE-inhibitory activity, respectively. Pro-Pro was identified in peptide sequences with ABTS radical scavenging activity as an active component while Pro-Gln was identified in peptide sequences with ACE-inhibitory activity. As a result, Pro-Pro and Pro-Gln, respectively, are likely-one of the characteristics of antioxidant and ACE-inhibitory peptides from MBP and ABP. Compared to mung bean and adzuki bean protein as substrate, Alcalase and Flavourzyme as peptidases significant impacted the development of distinct functionalities and biological activities.

Why Are Lopinavir and Ritonavir Effective against the Newly Emerged Coronavirus 2019? Atomistic Insights into the Inhibitory Mechanisms.

Since the emergence of a novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported from Wuhan, China, neither a specific vaccine nor an antiviral drug against SARS-CoV-2 has become available. However, a combination of two HIV-1 protease inhibitors, lopinavir and ritonavir, has been found to be effective against SARS-CoV, and both drugs could bind well to the SARS-CoV 3C-like protease (SARS-CoV 3CLpro). In this work, molecular complexation between each inhibitor and SARS-CoV-2 3CLpro was studied using all-atom molecular dynamics simulations, free energy calculations, and pair interaction energy analyses based on MM/PB(GB)SA and FMO-MP2/PCM/6-31G* methods. Both anti-HIV drugs interacted well with the residues at the active site of SARS-CoV-2 3CLpro. Ritonavir showed a somewhat higher number atomic contacts, a somewhat higher binding efficiency, and a somewhat higher number of key binding residues compared to lopinavir, which correspond with the slightly lower water accessibility at the 3CLpro active site. In addition, only ritonavir could interact with the oxyanion hole residues N142 and G143 via the formation of two hydrogen bonds. The interactions in terms of electrostatics, dispersion, and charge transfer played an important role in the drug binding. The obtained results demonstrated how repurposed anti-HIV drugs could be used to combat COVID-19.