Extracellular Matrix Mimicking Wound Microenvironment Responsive Amyloid-Heparin@TAAgNP Co-Assembled Hydrogel: An Effective Conductive Antibacterial Wound Healing Material.

Bioengineered composite hydrogel platforms made of a supramolecular coassembly have recently garnered significant attention as promising biomaterial-based healthcare therapeutics. The mechanical durability of amyloids, in conjunction with the structured charged framework rendered by biologically abundant key ECM component glycosaminoglycan, enables us to design minimalistic customized biomaterial suited for stimuli responsive therapy. In this study, by harnessing the heparin sulfate-binding aptitude of amyloid fibrils, we have constructed a pH-responsive extracellular matrix (ECM) mimicking hydrogel matrix. This effective biocompatible platform comprising heparin sulfate-amyloid coassembled hydrogel embedded with polyphenol functionalized silver nanoparticles not only provide a native skin ECM-like conductive environment but also provide wound-microenvironment responsive on-demand superior antibacterial efficacy for effective diabetic wound healing. Interestingly, both the cytocompatibility and antibacterial properties of this bioinspired matrix can be fine-tuned by controlling the mutual ratio of heparin sulfate-amyloid and incubated silver nanoparticle components, respectively. The designed biomaterial platform exhibits notable effectiveness in the treatment of chronic hyperglycemic wounds infected with multidrug-resistant bacteria, because of the integration of pH-responsive release characteristics of the incubated functionalized AgNP and the antibacterial amyloid fibrils. In addition to this, the aforementioned assemblage shows exceptional hemocompatibility with significant antibiofilm and antioxidant characteristics. Histological evidence of the incised skin tissue sections indicates that the fabricated composite hydrogel is also effective in controlling pro-inflammatory cytokines such as IL6 and TNFα expressions at the wound vicinity with significant upregulation of angiogenesis markers like CD31 and α-SMA.

Next generation antimitotic ß-carboline derivatives modulate microtubule dynamics and downregulate NF-κB, ERK 1/2 and phospho HSP 27.

AIM: Exploring the efficacy of ß-carboline-based molecular inhibitors in targeting microtubules for the development of novel anticancer therapeutics. MATERIALS AND METHODS: We synthesized a series of 1-Aryl-N-substituted-ß-carboline-3-carboxamide compounds and evaluated their cytotoxicity against human lung carcinoma (A549) cells using the MTT assay. Normal lung fibroblast cells (WI-38) were used to assess compound selectivity. The mechanism of action of MJ-211 was elucidated through Western blot analysis of key pro-apoptotic and cell cycle regulatory proteins. Additionally, the inhibitory effect of MJ-211 on multicellular 3D spheroid growth of A549 cells was evaluated. KEY FINDINGS: Lead compound MJ-211 exhibited remarkable cytotoxicity against A549 cells with an IC50 of 4.075 µM at 24 h treatment and IC50 of 1.7 nM after 72 h of treatment, while demonstrating selectivity towards normal WI-38 cells. MJ-211 activated pro-apoptotic factors Bim and p53, and suppressed Cyclin B1, Phospho HSP 27, BubR1, Mad 2, ERK1/2, and NF-κB, indicating its potent antimitotic and pro-apoptotic effects. MJ-211 significantly suppressed the migration of cells and inhibited the growth of A549 cell-derived multicellular 3D spheroids, highlighting its efficacy in a more physiologically relevant model. SIGNIFICANCE: Cytotoxic effect of MJ-211 against cancer cells, selectivity towards normal cells, and ability to modulate key regulatory proteins involved in apoptosis and cell cycle progression underscore its potential as a promising template for further anticancer lead optimization. Moreover, the inhibitory effect of MJ-211 on multicellular spheroid growth suggests its efficacy in combating tumor heterogeneity and resistance mechanisms, thereby offering a promising avenue for future anticancer drug development.

Ratiometric Fluorescent Probe Promotes Trans-differentiation of Human Mesenchymal Stem Cells to Neurons.

Development of multifunctional theranostics is challenging and crucial for deciphering complex biological phenomena and subsequently treating critical disease. In particular, development of theranostics for traumatic brain injury (TBI) and understanding its repair mechanism are challenging and highly complex areas of research. Recently, there have been interesting pieces of research work demonstrated that a small molecule-based neuroregenerative approach using stem cells has potential for future therapeutic lead development for TBI. However, these works demonstrated the application of a mixture of multiple molecules as a "chemical cocktail", which may have serious toxic effects in the differentiated cells. Therefore, development of a single-molecule-based potential differentiating agent for human mesenchymal stem cells (hMSCs) into functional neurons is vital for the upcoming neuro-regenerative therapeutics. This lead could be further extraploted for the design of theranostics for TBI. In this study, we have developed a multifunctional single-molecule-based fluorescent probe, which can image the transdifferentiated neurons as well as promote the differentiation process. We demonstrated a promising class of fluorescent probes (CP-4) that can be employed to convert hMSCs into neurons in the presence of fibroblast growth factor (FGF). This fluorescent probe was used in cellular imaging as its fluorescence intensity remained unaltered for up to 7 days of trans-differentiation. We envision that this imaging probe can have an important application in the study of neuropathological and neurodegenerative studies.

Designed novel nuclear localizing anticancer peptide targets p53 negative regulator MDM2 protein.

Intracellular protein-protein interactions provide a major therapeutic target for the development of peptide-based anticancer therapeutic agents. MDM2 is the 491-residue protein encoded by the MDM2 oncogene. Being a ubiquitin-protein ligase, MDM2 represses the transcription ability of the tumor suppressor p53 by proteasome-mediated degradation. Under typical cellular circumstances, a sustained p53 expression level is maintained by negative regulation of MDM2, whereas under stress conditions, this is alleviated to increase the p53 level. Modulation of MDM2-p53 interaction via fabrication of an MDM2-interacting peptide could be a useful strategy to inhibit subsequent proteasomal degradation of p53 and initiation of p53 signaling leading to the initiation of p53-mediated apoptosis of tumor cells. Here, in this research work, a novel anticancer peptide mPNC-NLS targeting the nucleus and the MDM2 protein (p53 negative regulator) was designed to promote the p53 protein activity for the prevention of cancer. It induces effective apoptosis in both A549 and U87 cells and remains non-cytotoxic to normal lung fibroblast cells (WI38). Further, immunocytochemistry and Western blot results confirm that the designed mPNC-NLS peptide induces the apoptotic death of lung cancer cells via activation of p53 and p21 proteins and remarkably stifled the in vitro growth of 3D multicellular spheroids composed of A549 cells.

Ebselen: A Review on its Synthesis, Derivatives, Anticancer Efficacy and Utility in Combating SARS-COV-2.

Ebselen is a selenoorganic chiral compound with antioxidant properties comparable to glutathione peroxidase. It is also known as 2-phenyl-1,2-benzisoselenazol-3(2H)-one. In studies examining its numerous pharmacological activities, including antioxidant, anticancer, antiviral, and anti-Alzheimer's, ebselen has demonstrated promising results. This review's primary objective was to emphasize the numerous synthesis pathways of ebselen and their efficacy in fighting cancer. The data were collected from multiple sources, including Scopus, PubMed, Google Scholar, Web of Science, and Publons. The starting reagents for the synthesis of ebselen are 2-aminobenzoic acid and N-phenyl benzamide. It was discovered that ebselen has the ability to initiate apoptosis in malignant cells and prevent the formation of new cancer cells by scavenging free radicals. In addition, ebselen increases tumor cell susceptibility to apoptosis by inhibiting TNF-α mediated NF-jB activation. Ebselen can inhibit both doxorubicin and daunorubicin-induced cardiotoxicity. Allopurinol and ebselen administered orally can be used to suppress renal ototoxicity and nephrotoxicity. Due to excessive administration, diclofenac can induce malignancy of the gastrointestinal tract, which ebselen can effectively suppress. Recent research has demonstrated ebselen to inhibit viral function by binding to cysteine-containing catalytic domains of various viral proteases. It was discovered that ebselen could inhibit the catalytic dyad function of Mpro by forming an irreversible covalent bond between Se and Cys145, thereby altering protease function and inhibiting SARS-CoV-2. Ebselen may also inhibit the activation of endosomal NADPH oxidase of vascular endothelial cells, which is believed to be required for thrombotic complications in COVID-19. In this review, we have included various studies conducted on the anticancer effect of ebselen as well as its inhibition of SARS-CoV-2.

Amyloid-Inspired Engineered Multidomain Amphiphilic Injectable Peptide Hydrogel─An Excellent Antibacterial, Angiogenic, and Biocompatible Wound Healing Material.

The ingrained mechanical robustness of amyloids in association with their fine-tunable physicochemical properties results in the rational design and synthesis of tailor-made biomaterials for specific applications. However, the incredible antimicrobial efficacy of these ensembles has largely been overlooked. This research work provides an insight into the interplay between self-assembly and antimicrobial activity of amyloid-derived peptide amphiphiles and thereby establishes a newfangled design principle toward the development of potent antimicrobial materials with superior wound healing efficacy. Apart from the relationship with many neurodegenerative diseases, amyloids are now considered as an important cornerstone of our innate immune response against pathogenic microbes. Impelled by this observation, a class of amphiphilic antimicrobial peptide-based biomaterial has been designed by taking Aß42 as a template. The designed AMP due to its amphipathic nature undergoes rapid self-assembly to form a biocompatible supramolecular hydrogel network having significant antibacterial as well as wound healing effectivity on both Gram-negative P. aeruginosa and MRSA-infected diabetic wounds via reduced inflammatory response and enhanced angiogenesis. Results suggest that disease-forming amyloids can be used as a blueprint for the fabrication of biomaterial-based antimicrobial therapeutics by fine-tuning both the hydrophobicity of the ß-aggregation prone zone as well as membrane interacting cationic residues.

Evolution of Potential Antimitotic Stapled Peptides from Multiple Helical Peptide Stretches of the Tubulin Heterodimer Interface: Helix-Mimicking Stapled Peptide Tubulin Inhibitors.

Protein-protein interactions play a crucial role in microtubule dynamics. Microtubules are considered as a key target for the design and development of anticancer therapeutics, where inhibition of tubulin-tubulin interactions plays a crucial role. Here, we focused on a few key helical stretches at the interface of α,ß-tubulin heterodimers and developed a structural mimic of these helical peptides, which can serve as potent inhibitors of microtubule polymerization. To induce helicity, we have made stapled analogues of these sequences. Thereafter, we modified the lead sequences of the antimitotic stapled peptides with halo derivatives. It is observed that halo-substituted stapled peptides follow an interesting trend for the electronegativity of halogen atoms in interaction patterns with tubulin and a correlation in the toxicity profile. Remarkably, we found that para-fluorophenylalanine-modified stapled peptide is the most potent inhibitors, which perturbs microtubule dynamics, induces apoptotic death, and inhibits the growth of melanoma.

A potent estrogen receptor and microtubule specific purine-benzothiazole-based fluorescent molecular probe induces apoptotic death of breast cancer cells.

Breast cancer is the most common malignancy in women and is a heterogeneous disease at molecular level. Early detection and specificity are the key prerequisite for the treatment of this deadly cancer. To address these issues attention on the breast cancer specific receptor protein(s) is the most realistic option. Herein estrogen (E) and progesterone (Pg) receptors(R) were considered to design fluorescent molecular probes with possible therapeutic option. We adopted QSAR technique to design a library of benzothiazole-purine hybrid molecules. Molecular docking offers us three screened molecules as most potential. Among these molecules one abbreviated as "CPIB" showed blue fluorescence and detected ER positive cancer cells at 1 nM concentration. At elevated concentration, CPIB induces apoptotic deaths of same cancer cells through targeting intracellular microtubules without affecting normal cells or ER negative cells. CPIB is one of its kind with two-in-one potential of "Detection and Destroy" ability targeting ER positive breast cancer cells.

Designed hybrid anticancer nuclear-localized peptide inhibits aggressive cancer cell proliferation.

Cell proliferation is a crucial step that might promote cancer if deregulated. Therefore, this vital segment is critically controlled by a complicated cell-cycle process in normal cells that is regulated by some regulatory proteins. It has been observed that p16 protein, playing a crucial role in cell-cycle progression/regulation, remains inactivated in different cancer cells. This inactivity of p16 protein leads to the enhancement of cancer cell proliferation by allowing uncontrolled cancer cell division. Hence, the activity of p16 protein needs to be restored using new viral vectors, small molecules as well as peptides to control/suppress this type of abnormal cell proliferation. In this work, we have taken an interesting approach to increase the efficiency and bio-availability of p16 peptide (functional part of p16 protein) to be an aggressive anti-leukemia therapeutic agent by conjugating a nuclear-localized signal (NLS) sequence and a short peptide (AVPI) with it. Moreover, this newly designed NLS attached hybrid peptide greatly affects XIAP expressing but p16 lower expressing human chronic myelogenous leukemia (CML) cell proliferation by targeting both nuclear (CDK4/cyclin D) and cellular factors (XIAP) and promoting the caspase-3 dependent apoptosis pathway.

Fluorine Substituted Proline Enhances the Tubulin Binding Potential of a Tetrapeptide at the GTP Binding Pocket Causing the Inhibition of Microtubule Motility and an Antimitotic Effect.

The microtubule is regarded as the key target for designing anticancer and neurotherapeutic drugs due to its functional importance in eukaryotic cells including neurons. The microtubule is a dynamic hollow polymer tube consisting of α,ß-tubulin heterodimer. Polymerization of α,ß-tubulin heterodimer resulted in microtubule formation. GTP plays a crucial role in microtubule polymerization. It binds at the exchangeable binding site of the ß-tubulin heterodimer, and it is one of the most crucial therapeutic hot spots for designing anticancer therapeutics. In this manuscript, we have shown using an in silico strategy and various in vitro and cellular experiments that the binding affinity to the tubulin and cancer therapeutic potential of an exchangeable GTP/GDP binding antimitotic tetrapeptide (SP: Ser-Leu-Arg-Pro) is increased through changing proline with the multifluorine substituted proline. This study showcases the importance of the proline amino acid and its pyrrolidine ring in the regulation of binding with tubulin at the GTP binding pocket.

A Small Molecule with Bridged Carbonyl and Tri-fluoro-aceto-phenone Groups Impedes Microtubule Dynamics and Subsequently Triggers Cancer Cell Apoptosis.

We identified a new microtubule targeted small molecule, which showed significant anticancer activity and induced apoptotic death of cancer cells. Precisely the central bridged carbonyl group and trifluoro-acetophenone group of a bis-benzothiazole molecule (BBT) interacts with tubulin close to the curcumin site and perturbs microtubule dynamics as well as causes microtubule depolymerization. We observed a significant enhancement of fluorescence while BBT interacts with the tubulin through bridged carbonyl moiety, a similar phenomenon to colchicine. Further, BBT activates tumor-suppressing bim and p53-puma axes to inhibit cancer survival. It also shows promising results against a tumor spheroid model. BBT is also capable of tumor regression, which shows that this molecule can serve as a potential template for the design of next-generation microtubule targeted anticancer drugs.

Power of an Organic Electron Acceptor in Modulation of Intracellular Mitochondrial Reactive Oxygen Species: Inducing JNK- and Caspase-Dependent Apoptosis of Cancer Cells.

Here, we demonstrate an interesting strategy of modulating mitochondrial reactive oxygen species (ROS) using the organic electron acceptor molecule carbonyl-bridged bithiazole attached with bis-trifluoroacetophenone (BBT). This molecule was found to affect complex I activity. It has the propensity to bind close to the flavin mononucleotide site of complex I of mitochondria where it traps electron released from nicotinamide adenine dinucleotide (NADH) and elevates intracellular ROS, which suggests that the bridged carbonyl in BBT plays a crucial role in the acceptance of electron from NADH. We understand that the potential of the NADH/NAD+ redox couple and low-lying LUMO energy level of BBT are compatible with each other, thus favoring its entrapment of released electrons in complex I. This effect of BBT in ROS generation activates JNK and p38 stress-dependent pathways and resulted in mitochondrial-dependent apoptotic cell death with the reduction in expression of several important cyto-protecting factors (Hsp27 and NFκB), indicating its potential in inhibition of cancer cell relapse. Intriguingly, we found that BBT is not a P-glycoprotein substrate, which further reveals its excellent anticancer potential. This study enlightens us on how the power of electron acceptor ability became an emerging strategy for modulation of intracellular function.

1,3,5-Triazine: A versatile pharmacophore with diverse biological activities.

1,3,5-Triazine and its derivatives have been the epicenter of chemotherapeutic molecules due to their effective biological activities, such as antibacterial, fungicidal, antimalarial, anticancer, antiviral, antimicrobial, anti-inflammatory, antiamoebic, and antitubercular activities. The present review represents a summarized report of the crucial biological activities possessed by substituted 1,3,5-triazine derivatives, with special attention to the most potent compounds.

Recent trends in the development of peptide and protein-based hydrogel therapeutics for the healing of CNS injury.

Traumatic brain injury (TBI) and spinal cord injury (SCI) cause millions of deaths and permanent or prolonged physical disabilities around the globe every year. It generally happens due to various incidents, such as accidents during sports, war, physical assault, and strokes which result in severe damage to brain and spinal cord. If this remains untreated, traumatic CNS injuries may lead to early development of several neurodegenerative diseases like Alzheimer's, Parkinson, multiple sclerosis, and other mental illnesses. The initial physical reaction, which is also termed as the primary phase, includes swelling, followed by inflammation as a result of internal haemorrhage causing damage to indigenous tissue, i.e., axonal shear injury, rupture of blood vessels, and partial impaired supply of oxygen and essential nutrients in the neurons, thereby initiating a cascade of events causing secondary injuries such as hypoxia, hypotension, cognitive impairment, seizures, imbalanced calcium homeostasis and glutamate-induced excitotoxicity resulting in concomitant neuronal cell death and cumulative permanent tissue damage. In the modern era of advanced biomedical technology, we are still living with scarcity of the clinically applicable comparative non-invasive therapeutic strategies for regeneration or functional recovery of neurons or neural networks after a massive CNS injury. One of the key reasons for this scarcity is the limited regenerative ability of neurons in CNS. Growth-impermissive glial scar and the lack of a synthetic biocompatible platform for proper neural tissue engineering and controlled supply of drugs further retard the healing process. Injectable or implantable hydrogel materials, consisting majorly of water in its porous three-dimensional (3D) structure, can serve as an excellent drug delivery platform as well as a transplanted cell-supporting scaffold medium. Among the various neuro-compatible bioinspired materials, we are limiting our discussion to the recent advancement of engineered biomaterials comprising mainly of peptides and proteins due to their growing demand, low immunogenicity and versatility in the fabrication of neuro regenerative medicine. In this article, we try to explore all the recent scientific avenues that are developing gradually to make peptide and peptide-conjugated biomaterial hydrogels as a therapeutic and supporting scaffold for treating CNS injuries.

Cell-Derived Exosome Therapy: A Novel Approach to Treat Post-traumatic Brain Injury Mediated Neural Injury.

Traumatic brain injury (TBI) causes serious neuronal injury that often leads to death. To date there is no clinically successful treatment strategy that has been reported which offers repair of the brain injury or neural injury. Significant attempts have been made to develop effective therapies for TBI, and one of the most promising approaches is a stem cell based therapeutic approach with mesenchymal stem cells (MSCs). This approach is regarded as having the most potential in regenerative medicine. Toward this venture, the generation and release of exosomes can be attributed to the therapeutic effects of MSCs. Exosomes are nanosized vesicles, carry proteins, lipids, mRNA, and miRNA, and assist in cell-cell communication. Exosomes can interact with brain parenchyma cells and with the neurogenic niche, which can help in neurogenesis and brain remodeling. Exosomes derived from MSCs and human-induced pluripotent stem cells (hiPSCs) can be a promising approach in neuronal injury healing. In this Viewpoint, we discussed the most recent knowledge for exosome therapies for neural injuries and highlighted the major advantages of this therapy.

Neurological Insights of COVID-19 Pandemic.

The novel coronavirus SARS-CoV-2, which was identified after a recent outbreak in Wuhan, China, in December 2019, has kept the whole world in tenterhooks due to its severe life-threatening nature of the infection. The virus is unlike its previous counterparts, SARS-CoV and MERS-CoV, or anything the world has encountered before both in terms of virulence and severity of the infection. If scientific reports relevant to the SARS-CoV-2 virus are noted, it can be seen that the virus owes much of its killer properties to its unique structure that has a stronger binding affinity with the human angiotensin-converting enzyme 2 (hACE2) protein, which the viruses utilize as an entry point to gain accesses to its hosts. Recent reports suggest that it is not just the lung that the virus may be targeting; the human brain may soon emerge as the new abode of the virus. Already instances of patients with COVID-19 have been reported with mild (anosmia and ageusia) to severe (encephalopathy) neurological manifestations, and if that is so, then it gives us more reasons to be frightened of this killer virus. Keeping in mind that the situation does not worsen from here, immediate awareness and more thorough research regarding the neuroinvasive nature of the virus is the immediate need of the hour. Scientists globally also need to up their game to design more specific therapeutic strategies with the available information to counteract the pandemic. In this Viewpoint, we provide a brief outline of the currently known neurological manifestations of COVID-19 and discuss some probable ways to design therapeutic strategies to overcome the present global crisis.

Tracking the Footprints of Paclitaxel Delivery and Mechanistic Action via SERS Trajectory in Glioblastoma Cells.

The design and development of an efficacious tumor-specific drug-delivery system is a challenging task. In this study, we have synthesized target-specific small peptide substrates on an octaguanidine sorbitol scaffold, named small molecular targeted drug-delivery conjugate (SMTDDC). The SMTDDC fabrication, with dual targeting cRGD and Cathepsin B (Cath B)-specific tripeptide (Glu-Lys-Phe), altered the microtubule network of glioblastoma cells by the orchestrated release of the cytotoxic paclitaxel (PTX). Cath B assisted PTX delivery was monitored by high-performance liquid chromatography and Surface-Enhanced Raman Scattering (SERS) modalities. The time-dependent SERS fingerprinting and imaging revealed a fast and accurate PTX release profile and subsequent in vitro cytotoxicity as well as the apoptotic events and microtubule network alteration in U-87 MG glioblastoma cells. Furthermore, SMTDDC displayed adequate stability under physiological conditions and demonstrated biocompatibility toward red blood cells and lymphocytes. This study indicated a new insight on SERS-guided peptidomimetic sorbitol molecular transporter, enabling a greater promise with high potential for the further development of PTX delivery in glioblastoma treatment.

Extracellular Matrix (ECM)-Mimicking Neuroprotective Injectable Sulfo-Functionalized Peptide Hydrogel for Repairing Brain Injury.

Brain injury can lead to the loss of neuronal functions and connections, along with the damage of the extracellular matrix (ECM). Thus, it ultimately results in devastating long-term damage, and recovery from this damage is a challenging task. To address this issue, we have designed a sulfo-group-functionalized injectable biocompatible peptide hydrogel, which not only mimics the ECM and supports the damaged neurons but also releases a neurotrophic factor around the injured sites of the brain in the presence of the matrix metalloproteinase 9 (MMP9) enzyme. It has also been observed that the driving force of hydrogel formation is a ß-sheet secondary structure and π-π stacking interactions between Phe-Phe moieties. The hydrogel is able not only to promote neurite outgrowth of PC12-derived neurons and primary neurons cultured in its presence but also to nullify the toxic effects of anti-nerve growth factor (Anti-NGF)-induced neurons. It also promotes the expression of vital neuronal markers in rat cortical primary neurons, displays substantial potential in neuroregeneration, and also promotes fast recovery of the sham injured mice brain. Increased expression of reactive astrocytes in the hippocampal dentate gyrus region of the sham injured brain clearly suggests its tremendous ability in the neural repair of the damaged brain. Thus, we can convincingly state that our hydrogel is capable of repairing brain injury by mimicking an ECM-like environment and providing neuroprotection to the damaged neurons.

A bis-indole/carbazole based C5-curcuminoid fluorescent probe with large Stokes shift for selective detection of biothiols and application to live cell imaging.

A series of heterocyclic C5-curcuminoids (bis(arylmethylidene)acetones) (PJ1-PJ6) having a large Stokes shift (Δλ = 104-173 nm) have been synthesized for the selective detection of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) in living cells. The compounds were synthesized using a new methodology via deacetylation under microwave conditions. The photophysical properties of these compounds have been studied. Prominent colour changes from bright yellow to colourless in the presence of thiols were observed for PJ1. Live cell imaging has been employed with PJ1 for the utilization of the probe to detect homocysteine in A375 cells and apoptosis in AGS cells.

The role of isoaspartate in fibrillation and its prevention by Protein-L-isoaspartyl methyltransferase.

BACKGROUND: Isomerization of aspartate to isoaspartate (isoAsp) on aging causes protein damage and malfunction. Protein-L-isoaspartyl methyltransferase (PIMT) performs a neuroprotective role by repairing such residues. A hexapeptide, Val-Tyr-Pro-(isoAsp)-His-Ala (VA6), a substrate of PIMT, is shown to form fibrils, while the normal Asp-containing peptide does not. Considering the role of PIMT against epileptic seizure, the combined effect of PIMT and two antiepileptic drugs (AEDs) (valproic acid and stiripentol) was investigated for anti-fibrillation activity. METHODS: Structural/functional modulations due to the binding of AEDs to PIMT were investigated using biophysical techniques. Thioflavin T (ThT) fluorescence assay and microscopic methods were employed to study fibril formation by VA6. In vitro experiments with PC12 cells were carried out with PIMT/AEDs. RESULTS: ThT assay indicated reduction of fibrillation of VA6 by PIMT. AEDs stabilize PIMT, bind close to the cofactor binding site, possibly exerting allosteric effect, increase the enzymatic activity, and anti-fibrillation efficacy. Furthermore, Aß42, implicated in Alzheimer's disease, undergoes ß-sheet to α-helix transition in presence of PIMT. Studies with PC12 derived neurons showed that PIMT and PIMT/AEDs exerted neuroprotective effect against anti-NGF induced neurotoxicity. This was further validated against neurotoxicity induced by Aß42 in primary rat cortical neurons. CONCLUSIONS: The study provides a new perspective to the role isoAsp in protein fibrillation, PIMT in its prevention and AEDs in enhancing the activity of the enzyme. GENERAL SIGNIFICANCE: IsoAsp, with an additional C atom in the main-chain of polypeptide chain, may make it more susceptible to fibrillation. PIMT alone, or in association with AEDs prevents this.