Computational Peptide Design Cotargeting Glucagon and Glucagon-like Peptide-1 Receptors

Peptides are sustainable alternatives to conventional therapeutics for G protein-coupled receptor (GPCR) linked disorders, promising biocompatible and tailorable next-generation therapeutics for metabolic disorders including type-2 diabetes, as agonists of the glucagon receptor (GCGR) and the glucagon-like peptide-1 receptor (GLP-1R). However, single agonist peptides activating GLP-1R to stimulate insulin secretion also suppress obesity-linked glucagon release. Hence, bioactive peptides cotargeting GCGR and GLP-1R may remediate the blood glucose and fatty acid metabolism imbalance, tackling both diabetes and obesity to supersede current monoagonist therapy. Here, we design and model optimized peptide sequences starting from peptide sequences derived from earlier phage-displayed library screening, identifying those with predicted molecular binding profiles for dual agonism of GCGR and GLP-1R. We derive design rules from extensive molecular dynamics simulations based on peptide-receptor binding. Our newly designed coagonist peptide exhibits improved predicted coupled binding affinity for GCGR and GLP-1R relative to endogenous ligands and could in the future be tested experimentally, which may provide superior glycemic and weight loss control.

Physicochemical n-Grams Tool: A tool for protein physicochemical descriptor generation via Chou's 5-step rule

Physicochemical n-Grams Tool (PnGT) is an open-source standalone software for calculating physicochemical descriptors of protein. PnGT was developed using the Python scripting language and developed the user interface using Tkinter. The software currently calculates 33 physicochemical descriptors along with the sequence length for the given protein primary sequence. The descriptor generated by this tool can be directly utilized as the feature vector for the development of proteomics statistical or machine learning predictive model.

Modulatory effects of an NMDAR partial agonist in MK-801-induced memory impairment

RATIONALE

Acute administration of the N-methyl-d-aspartate (NMDA) non-competitive antagonist, MK-801, impairs novel object recognition (NOR), locomotor activity in open field (OF) and conditioned taste aversion (CTA) in rodents. NMDAR partial agonist d-cycloserine (DCS) reverses these effects in NOR and CTA via modulation of glutamatergic, cholinergic and dopaminergic systems.

OBJECTIVES AND METHODS

To test this hypothesis, we investigated the effects of DCS, a partial NMDAR agonist, on NOR memory, locomotor activity, and CTA memory in Wistar rats on NMDA-glutamate receptor antagonism by MK-801. The potential involvement of dopaminergic and cholinergic systems in improving cognitive functions was explored. MK-801-induced cognitive deficits were assessed using NOR, OF and CTA paradigms. MK-801-induced dopamine release increase in acetylcholinesterase (AChE), mono amine oxidase (MAO) activity and increase in c-fos expression were also investigated.

RESULTS

The effects caused by MK-801 (0.2 mg/kg) were inhibited by administration of the NMDA receptor agonist DCS (15 mg/kg). NOR and CTA paradigms inhibited by MK-801 were attenuated by DCS administration. Moreover, DCS also blocked the MK-801-induced abnormal increase in dopamine content, AChE activity and MAO activity. However, c-fos overexpression was controlled to some extent only.

CONCLUSIONS

Based on the NMDAR hypo function hypothesis in some neuropsychiatric disorders, our finding suggests that improving NMDAR hypo function by agonist DCS may play a significant role.

Phaco-emulsification aspiration procedure: an evaluation

The results phaco-emulsification aspiration procedure have been evaluated in 50 cataract patients, by observing the final visual acuity achieved and astigmatic error induced, along with incidence of various operative and post-operative complications. Majority of the patients who did not have serious preoperative complications achieved good vision. The procedure has proved to be equally effective for cataracts occurring in the younger age group.