Identification of DPP-IV inhibitory peptides derived from buffalo colostrum: Mining through bioinformatics, in silico and in vitro approaches.

Bioactive peptides derived from foods provide physiological health benefits beyond nutrition. This study focused on profiling small peptide inhibitors against two key serine proteases, dipeptidyl peptidase-IV (DPP-IV) and prolyl oligopeptidase (POP). DPP-IV is a well-known protein involved in diverse pathways regulating inflammation, renal, cardiovascular physiology, and glucose homeostasis. POP is yet another key target protein for neurodegenerative disorders. The study evaluated peptide libraries of buffalo colostrum whey and fat globule membrane proteins derived from pepsin and pepsin-pancreatin digestion through in silico web tools and structure-based analysis by molecular docking and binding free-energy estimation, followed by in vitro assay for DPP-IV inhibition for the lead peptides. The bioinformatic study indicated 49 peptides presented motifs with DPP-IV inhibition while 5 peptides with sequences for POP inhibition. In the molecular docking interactions study, 22 peptides interacted with active site residues of DPP-IV and 3 peptides with that of POP. The synthesized peptides, SFVSEVPEL and LTFQHNF inhibited DPP-IV in vitro with an IC50 of 193.5 µM and 1.782 mM, respectively. The study revealed the key residues for inhibition of DPP-IV and POP thus affirming the DPP-IV inhibitory potential of milk-derived peptides.

Buffalo colostrum peptide mitigates Parkinson's disease pathophysiology through Cullin-3 inhibition.

Colostrum/Milk is a chief repertoire of antioxidant peptides. Nuclear factor-erythroid 2 related factor 2 (Nrf2) is a viable target for Parkinson's Disease (PD), as this pathway deduced to be impaired in PD. Cullin-3 is one of the crucial E3 ligase responsible for its regulation. The present study screened peptide libraries of buffalo colostrum & milk peptides for Cullin-3 inhibition, thus ensuing activation of Nrf2 to alleviate the molecular etiopathology in PD using the C. elegans as a model. The structure was modelled, binding sites analyzed and peptide-interactions analyzed by docking. Among the 55 sequences (≤1 kDa), the peptide SFVSEVPEL having the highest dock score (-16.919) was synthesized and evaluated for its effects on oxidative stress markers, antioxidant enzymes, neurochemical marker and Nrf2/Skn-1 levels. The lead peptide alleviated the oxidative pathophysiology and behavioural deficits associated with PD in C. elegans.

Identification of Potential Peptide Inhibitors of ACE-2 Target of SARS-CoV-2 from Buckwheat & Quinoa.

It is well established fact that peptides from various foods offer human health benefits displaying diverse functionalities. Millets considered as super foods is a major alternative in recent days for traditional diet being rich in proteins and fibre along with trace minerals and vitamins. In this connection, proteins from Buckwheat and Quinoa were digested by in vitro simulation digestion for the generation of peptides, analyzed by nLC-MS/MS and the functional annotations of the identified proteins/peptides were carried out. The study led to the identification of 34 small peptides and their parent proteins clustered into 4 gene functional groups and their localization prediction indicated their involvement in energy metabolism, transport and storage. Interestingly, the identified peptides maximally displayed DPP-IV and ACE inhibitions. The present study was extended to unravel ACE-2 inhibition targeting COVID-19 by selecting ACE-2-Spike binding domain for molecular docking studies. The NWRTVKYG interacted with the ACE-2-Spike interface displaying the feasible binding energy (- 213.63) and docking score (- 12.43) and the MD simulation revealed the ability of the peptide in stabilizing the protein-peptide composite. The present investigation thus establishes newer vista for food derived peptides having ACE-2 inhibitory potential as tentative strategy for SARS-CoV-2 therapeutics.

In silico and In vivo Evaluation of Oxidative Stress Inhibitors Against Parkinson's Disease using the C. elegans Model.

BACKGROUND: Parkinson's disease ranks second, after Alzheimer's as the major neurodegenerative disorder, for which no cure or disease-modifying therapies exist. Ample evidence indicate that PD manifests as a result of impaired anti-oxidative machinery leading to neuronal death wherein Cullin-3 has ascended as a potential therapeutic target for diseases involving damaged anti-oxidative machinery. OBJECTIVE: The design of target specific inhibitors for the Cullin-3 protein might be a promising strategy to increase the Nrf2 levels and to decrease the possibility of "off-target" toxic properties. METHODS: In the present study, an integrated computational and wet lab approach was adopted to identify small molecule inhibitors for Cullin-3. The rational drug designing process comprised homology modeling and derivation of the pharmacophore for Cullin-3, virtual screening of Zinc natural compound database, molecular docking and Molecular dynamics based screening of ligand molecules. In vivo validations of an identified lead compound were conducted in the PD model of C. elegans. RESULTS AND DISCUSSION: Our strategy yielded a potential inhibitor; (Glide score = -12.31), which was evaluated for its neuroprotective efficacy in the PD model of C. elegans. The inhibitor was able to efficiently defend against neuronal death in PD model of C. elegans and the neuroprotective effects were attributed to its anti-oxidant activities, supported by the increase in superoxide dismutase, catalase and the diminution of acetylcholinesterase and reactive oxygen species levels. In addition, the Cullin-3 inhibitor significantly restored the behavioral deficits in the transgenic C. elegans. CONCLUSION: Taken together, these findings highlight the potential utility of Cullin-3 inhibition to block the persistent neuronal death in PD. Further studies focusing on Cullin-3 and its mechanism of action would be interesting.

Discovery, synthesis, and in vitro evaluation of a novel bioactive peptide for ACE and DPP-IV inhibitory activity.

Biologically active or bioactive peptides are unique amino acid sequences found encrypted in food proteins. These peptides, upon hydrolysis, can exert positive physiological effects on human health, different from that of their native protein. These effects are brought about by their interaction with specific targets in the body, thereby, mimicking physiologically relevant peptides. Peptides are derived from food proteins, they are popular natural alternatives for the management of common metabolic disorders. In the present study, we aimed to identify bioactive peptide sequences (less than 3 kDa) from fat globule membrane protein (FGMP) hydrolysates of buffalo colostrum using a combination of empirical, computational and in vitro methods. The empirical approach aided in the identification of 89 FGMP peptides (m/z-415 to 2939) which were annotated and profiled for bioactivity. Few lead peptides were analyzed by molecular docking for the inhibitory potential of Angiotensin Converting Enzyme (ACE) and Dipeptidyl Peptidase-IV (DPP-IV). A heptapeptide (m/z-723.3) synthesized was found to inhibit ACE (IC50: 74.27 µM) and DPP-IV (IC50: 3.83 mM).