Misfolded Research Articles

Amyloidosis

Amyloidosis are rare protein misfolding and deposition diseases which, with very few exceptions, are treatable easily nowadays. The prognosis depends on the form of amyloidosis, which is particularly unfavorable for heart involvement that is diagnosed too late. Patients die within months to a few years or suffer irreversible loss of function of the affected organs. Once the diagnosis has been made, treatment should be started without delay. Amyloidosis centers offer support in the diagnosis and development as well as clinical trials of an optimal therapy concept.

Dynamic protein hydration water mediates the aggregation kinetics of amyloid β peptides at interfaces

Protein hydration water is essential for protein misfolding and amyloid formation, but how it directs the course of amyloid formation has yet to be elucidated. Here, we experimentally demonstrated that femtosecond sum frequency generation vibrational spectroscopy (SFG–VS) and the femtosecond IR pump–SFG probe technique can serve as powerful tools for addressing this issue. Using amyloid β(1–42) peptide as a model, we determined the transient misfolding intermediates by probing the amide band spectral features and the local hydration water changes by measuring the ultrafast vibrational dynamics of the amide I band. For the first time, we established a correlation between the dynamic change in protein hydration water and aggregation propensity. The aggregation propensity depends on the dynamic change in the hydration water, rather than the static hydration water content of the initial protein state. Water expulsion enhances the aggregation propensity and promotes amyloid formation, while protein hydration attenuates the aggregation propensity and inhibits amyloid formation. The suppression of water expulsion and protein hydration can prevent protein aggregation and stabilize proteins. These findings contribute to a better understanding of the underlying effect of hydration water on amyloid formation and protein structural stability and provide a strategy for maintaining long–term stabilization of biomolecules.

Discovery of Novel Inhibitors against ALS-Related SOD1(A4V) Aggregation through the Screening of a Chemical Library Using Differential Scanning Fluorimetry (DSF)

Background: Cu/Zn Superoxide Dismutase 1 (SOD1) is a 32 kDa cytosolic dimeric metalloenzyme that neutralizes superoxide anions into oxygen and hydrogen peroxide. Mutations in SOD1 are associated with ALS, a disease causing motor neuron atrophy and subsequent mortality. These mutations exert their harmful effects through a gain of function mechanism, rather than a loss of function. Despite extensive research, the mechanism causing selective motor neuron death still remains unclear. A defining feature of ALS pathogenesis is protein misfolding and aggregation, evidenced by ubiquitinated protein inclusions containing SOD1 in affected motor neurons. This work aims to identify compounds countering SOD1(A4V) misfolding and aggregation, which could potentially aid in ALS treatment. Methods: The approach employed was in vitro screening of a library comprising 1280 pharmacologically active compounds (LOPAC®) in the context of drug repurposing. Using differential scanning fluorimetry (DSF), these compounds were tested for their impact on SOD1(A4V) thermal stability. Results and Conclusions: Dimer stability was the parameter chosen as the criterion for screening, since the dissociation of the native SOD1 dimer is the step prior to its in vitro aggregation. The screening revealed one compound raising protein-ligand Tm by 6 °C, eleven inducing a higher second Tm, suggesting a stabilization effect, and fourteen reducing Tm from 10 up to 26 °C, suggesting possible interactions or non-specific binding.

Effects of treadmill exercise on endoplasmic reticulum protein folding and endoplasmic reticulum-associated protein degradation pathways in APP/PS1 mice

A hallmark of Alzheimer's disease (AD) is the disruption of protein homeostasis (proteostasis), manifested by the misfolding and aggregation of proteins. Molecular chaperones and the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway in the ER are essential for correct protein folding and degradation of misfolded proteins respectively, thus contributing to the maintenance of proteostasis. The present study aimed to investigate whether the beneficial effects of exercise in an AD mice model is associated with changes in ER protein folding and ERAD. APP/PS1 transgenic and wild-type mice were subjected to treadmill exercise for three months. The levels of molecular chaperones, specifically protein disulfide isomerases (PDIs) and heat shock proteins (HSPs), as well as ERAD-associated molecules were analyzed in the hippocampus. The result revealed a decrease in mRNA levels of PDIA2, PDIA3, PDIA4, PDIA5, PDIA6, HSPA1B, HSPA8, HSP90B1, DNAJB2, CRYAB, and CNX, an increase in mRNA levels of HSPA5 and HSPH1, an increase in protein levels of HERPUD1, and a decrease in protein levels of VCP in APP/PS1 mice. However, following a 3-month treadmill exercise regimen, an increase in mRNA levels of PDIA2, PDIA4, PDIA6, HSPA1A, HSPA8, HSP90AB1, and DNAJB2, as well as an increase in protein levels of VCP and DERL2, and a decrease in protein levels of HERPUD1 were noted. Overall, our findings indicate that disruptions in hippocampal ER protein folding and ERAD pathways may be implicated in AD, with exercise serving as a regulator of these pathways.

Christopher Martin Dobson. 8 October 1949 — 8 September 2019

Christopher Martin Dobson was a distinguished biophysical chemist who earned an international reputation for his work on protein folding, misfolding and aggregation. Protein folding is a crucial process in biochemistry where a protein transitions from a disordered state to a structured, three-dimensional form after being synthesized by a ribosome. This transformation is essential for the protein to attain its biological functionality. The intricate folding pathway is guided by various interactions between amino acids within the protein chain. When protein folding goes awry, it can lead to misfolded proteins, which are associated with various disorders such as Alzheimer's and Parkinson's disease. The study of protein folding and misfolding has significant implications for both basic science and medical research. Chris's career spanned almost five decades, resulted in more than 870 publications and established a legacy that will influence the lives of many for decades to come. His outstanding mentorship resulted in some 100 of his former students and post-docs taking up independent positions at academic institutions in all parts of the world, while his research work has left a lasting imprint on the biophysical sciences and inspired an entire generation of research scientists.

Metabolic perturbations associated with hIAPP-induced insulin resistance in skeletal muscles: Implications to the development of type 2 diabetes

The human islet amyloid polypeptide (hIAPP) tends to misfold and self-assemble to form amyloid fibrils, which has been associated with the loss of function and viability of pancreatic β-cells in type 2 diabetes mellitus (T2DM). The role of hIAPP in the development of insulin resistance (a hallmark of T2DM) in skeletal muscles – the major sites for glucose utilization – needs further investigation. Even though, insulin-resistant conditions have been known to stimulate hIAPP aggregation, the events that lead to the development of insulin resistance due to hIAPP aggregation in skeletal muscles remain unidentified. Here, we have attempted to identify metabolic perturbations in L6 myotubes that were exposed to increasing concentrations of recombinant hIAPP for different time durations. It was observed that hIAPP exposure was associated with increased mitochondrial and cellular ROS levels, loss in mitochondrial membrane potential and viability of the myotubes. Metabolomic investigations of hIAPP-treated myotubes revealed significant perturbations in o-phosphocholine, sn-glycero-3-phosphocholine and dimethylamine levels (p < 0.05). Therefore, we anticipate that defects in glycerophospholipid metabolism and the associated oxidative stress and membrane damage may play key roles in the development of insulin resistance due to protein misfolding in skeletal muscles. In summary, the perturbed metabolites and their pathways have not only the potential to be used as early biomarkers to predict the onset of insulin resistance and T2DM but also as therapeutic targets for the effective management of the same.

Proteases: Role in Various Human Diseases.

Proteases, a group of hydrolytic enzymes catalyzing the hydrolysis of peptide bonds, play pivotal roles in various physiological processes and have emerged as key contributors to the pathogenesis of diverse diseases. This work provides an insight into the impact of protease activity on different disease contexts, highlighting their involvement in cancer, inflammatory disorders, cardiovascular diseases, infectious diseases, and neurodegenerative conditions. In cancer, proteases facilitate tumor growth, invasion, and metastasis, while in inflammatory diseases, dysregulated protease activity exacerbates tissue damage and inflammation. Cardiovascular diseases involve proteases in extracellular matrix remodeling, affecting arterial structure. In infectious diseases, proteases play crucial roles in pathogen invasion and immune evasion. Neurodegenerative diseases are characterized by protease dysregulation, contributing to protein misfolding and aggregation. As research progresses, understanding the intricate relationships between proteases and diseases becomes essential for developing targeted therapeutic strategies. This review aims to provide a comprehensive glimpse into the diverse impact of protease activities on various diseases, emphasizing their potential as crucial players in the landscape of disease pathology and potential therapeutic interventions.

Use of the Novel Site-Directed Enzyme Enhancement Therapy (SEE-Tx) Drug Discovery Platform to Identify Pharmacological Chaperones for Glutaric Acidemia Type 1.

Allosteric regulators acting as pharmacological chaperones hold promise for innovative therapeutics since they target noncatalytic sites and stabilize the folded protein without competing with the natural substrate, resulting in a net gain of function. Exogenous allosteric regulators are typically more selective than active site inhibitors and can be more potent than competitive inhibitors when the natural substrate levels are high. To identify novel structure-targeted allosteric regulators (STARs) that bind to and stabilize the mitochondrial enzyme glutaryl-CoA dehydrogenase (GCDH), the computational site-directed enzyme enhancement therapy (SEE-Tx) technology was applied. SEE-Tx is an innovative drug discovery platform with the potential to identify drugs for treating protein misfolding disorders, such as glutaric acidemia type 1 (GA1) disease. Putative allosteric regulators were discovered using structure- and ligand-based virtual screening methods and validated using orthogonal biophysical and biochemical assays. The computational approach presented here could be used to discover allosteric regulators of other protein misfolding disorders.

An antireductant approach ameliorates misfolded proinsulin-induced hyperglycemia and glucose intolerance in male Akita mice.

Protein folding in the endoplasmic reticulum (ER) requires a high ratio of oxidized to reduced glutathione (GSSG/rGSH). Since the GSSG/rGSH depends on total glutathione (tGSH = GSSG + rGSH) levels, we hypothesized that limiting GSH biosynthesis will ameliorate protein misfolding by enhancing the ER oxidative milieu. As a proof-of-concept, we used DL-buthionine-(S,R)-sulfoximine (BSO) to inhibit GSH biosynthesis in Akita mice, which are prone to proinsulin misfolding. We conducted a 2-week intervention to investigate if BSO was safe and a 6-week intervention to find its effect on glucose intolerance. In both cohorts, male heterozygous Akita (AK) and wild-type (WT) mice were continuously administered 15mM BSO. No adverse effects were observed on body weight, food intake, and water intake in either cohort. Unaltered levels of plasma aspartate and alanine aminotransferases, and cystatin-C, indicate that BSO was safe. BSO-induced decreases in tGSH were tissue-dependent with maximal effects in the kidneys, where it altered the expression of genes associated with GSH biosynthesis, redox status, and proteostasis. BSO treatment decreased random blood glucose levels to 80% and 67%of levels in untreated mice in short-term and long-term cohorts, respectively, and 6-h fasting blood glucose to 82% and 74%of levels in untreated mice, respectively. BSO also improved glucose tolerance by 37% in AK mice in the long-term cohort, without affecting insulin tolerance. Neither glucose tolerance nor insulin tolerance were affected in WT. Data indicate that BSO might treat misfolded proinsulin-induced glucose intolerance. Future studies should investigate the effect of BSO on proinsulin misfolding and if it improves glucose intolerance in individuals with Mutant Insulin Diabetes of Youth.

Unraveling the Molecular Pathogenesis of Protein C Deficiency-Associated VTE: Insights from Protein C Mutations C238G and R189W in Thai Patients.

Protein C (PC) deficiency is a well-established risk factor for thromboembolism (TE), commonly manifesting in pediatric patients. This study aimed to elucidate the pathogenic mechanisms of two novel PC mutations, C238G and R189W, identified in Thai children with both venous and arterial TE. The effects of wild-type (WT), C238G, and R189W PC variants were investigated through transient transfection of HEK293T cells. PC secretion levels were measured, and immunofluorescence analysis was performed to assess intracellular localization. ER stress-related gene expression and UPR activation were evaluated. Structural analysis was conducted to explore the significance of the C238 and R189W residue in PC functionality. The C238G mutation led to a severe 95% reduction in PC secretion, while R189W showed a 30% decrease compared with WT. Immunofluorescence revealed that C238G-PC was predominantly retained in the ER, indicating protein misfolding. C238G-expressing cells exhibited significant upregulation of ER stress-related genes and UPR activation. In contrast, R189W resulted in only a modest increase in UPR gene expression, suggesting a less pronounced impact on protein folding and secretion. Structural analysis demonstrated the critical role of the C238 residue in maintaining PC's disulfide bond and overall conformation. This study reveals distinct molecular mechanisms by which the C238G and R189W mutations contribute to PC deficiency and increased thrombotic risk. The findings emphasize the essential role of the C238 residue in preserving PC structure and secretion, enhancing the understanding of PC deficiency-associated TE in pediatric patients.

Mutant p53 Misfolding and Aggregation Precedes Transformation into High-Grade Serous Ovarian Carcinoma.

High Grade Serous Ovarian Cancer (HG-SOC), the most prevalent and aggressive gynecological malignancy, is marked by ubiquitous loss of functional p53, largely due to point mutations that arise very early in carcinogenesis. These mutations often lead to p53 protein misfolding and subsequent aggregation, yet the alterations in intracellular p53 dynamics throughout ovarian cancer progression remain poorly understood. HG-SOC originates from the fallopian tube epithelium, with a well-documented stepwise progression beginning with early pre-malignant p53 signatures. These signatures represent largely normal cells that express and accumulate mutant p53, which then transform into benign serous tubal intraepithelial lesions (STIL), progress into late pre-malignant serous tubal intraepithelial carcinoma (STIC), and ultimately lead to HGSOC. Here, we show that the transition from folded, soluble to aggregated mutant p53 occurs during the malignant transformation of benign precursor lesions into HGSOC. We analyzed fallopian tube tissue collected from ten salpingo-oophorectomy cases and determined the proportion of cells carrying soluble versus mis-folded/mutant p53 through conformation-sensitive staining and quantification. Misfolded p53 protein, prone to aggregation, is present in STICs and HG-SOCs, but notably absent from preneoplastic lesions and surrounding healthy tissue. Overall, our results indicate that aggregation of mutant p53 is a structural defect that distinguishes preneoplastic early lesions from late premalignant and malignant ones, offering a potential treatment window for targeting p53 aggregation and halting ovarian cancer progression.

Protective role of cytosolic prion protein against virus infection in prion-infected cells.

Cytosolic PrP has been detected in prion-infected cells and suggested to be involved in the neurotoxicity of prions. Here, we also detected cytosolic PrP in prion-infected cells. We further found that the nuclear translocation of NF-κB was disturbed in prion-infected cells and that the N-terminal potential nuclear translocation signal of PrP expressed in the cytosol disturbed the nuclear translocation of NF-κB. Thus, the N-terminal nuclear translocation signal of cytosolic PrP might play a role in prion neurotoxicity. Prion-like protein aggregates in other protein misfolding disorders, including Alzheimer's disease were reported to play a protective role against various environmental stimuli. We here showed that prion-infected cells were partially resistant to IAV/WSN infection due to the cytosolic PrP-mediated disturbance of the nuclear translocation of NF-κB, which consequently activated NLRP3 inflammasomes after IAV/WSN infection. It is thus possible that prions could also play a protective role in viral infections.

Understanding Amyotrophic Lateral Sclerosis: Pathophysiology, Diagnosis, and Therapeutic Advances.

This review offers an in-depth examination of amyotrophic lateral sclerosis (ALS), addressing its epidemiology, pathophysiology, clinical presentation, diagnostic techniques, and current as well as emerging treatments. The purpose is to condense key findings and illustrate the complexity of ALS, which is shaped by both genetic and environmental influences. We reviewed the literature to discuss recent advancements in understanding molecular mechanisms such as protein misfolding, mitochondrial dysfunction, oxidative stress, and axonal transport defects, which are critical for identifying potential therapeutic targets. Significant progress has been made in refining diagnostic criteria and identifying biomarkers, leading to earlier and more precise diagnoses. Although current drug treatments provide some benefits, there is a clear need for more effective therapies. Emerging treatments, such as gene therapy and stem cell therapy, show potential in modifying disease progression and improving the quality of life for ALS patients. The review emphasizes the importance of continued research to address challenges such as disease variability and the limited effectiveness of existing treatments. Future research should concentrate on further exploring the molecular foundations of ALS and developing new therapeutic approaches. The implications for clinical practice include ensuring the accessibility of new treatments and that healthcare systems are equipped to support ongoing research and patient care.

Reduction of RAD23A extends lifespan and mitigates pathology in TDP-43 mice.

Protein misfolding and aggregation are cardinal features of neurodegenerative disease (NDD) and they contribute to pathophysiology by both loss-of-function (LOF) and gain-of-function (GOF) mechanisms. This is well exemplified by TDP-43 which aggregates and mislocalizes in several NDDs. The depletion of nuclear TDP-43 leads to reduction in its normal function in RNA metabolism and the cytoplasmic accumulation of TDP-43 leads to aberrant protein homeostasis. A modifier screen found that loss of rad23 suppressed TDP-43 pathology in invertebrate and tissue culture models. Here we show in a mouse model of TDP-43 pathology that genetic or antisense oligonucleotide (ASO)-mediated reduction in rad23a confers benefits on survival and behavior, histological hallmarks of disease and reduction of mislocalized and aggregated TDP-43. This results in improved function of the ubiquitin-proteasome system (UPS) and correction of transcriptomic alterations evoked by pathologic TDP-43. RAD23A-dependent remodeling of the insoluble proteome appears to be a key event driving pathology in this model. As TDP-43 pathology is prevalent in both familial and sporadic NDD, targeting RAD23A may have therapeutic potential.

Towards characterization of cell culture conditions for reliable proteomic analysis: in vitro studies on A549, differentiated THP-1, and NR8383 cell lines

Proteomic investigations result in high dimensional datasets, but integration or comparison of different studies is hampered by high variances due to different experimental setups. In addition, cell culture conditions can have a huge impact on the outcome. This study systematically investigates the impact of experimental parameters on the proteomic profiles of commonly used cell lines—A549, differentiated THP-1 macrophage-like cells, and NR8383—for toxicity studies. The work focuses on analyzing the influence at the proteome level of cell culture setup involving different vessels, cell passage numbers, and post-differentiation harvesting time, aiming to improve the reliability of proteomic analyses for hazard assessment. Mass-spectrometry-based proteomics was utilized for accurate protein quantification by means of a label-free approach. Our results showed that significant proteome variations occur when cells are cultivated under different setups. Further analysis of these variations revealed their association to specific cellular pathways related to protein misfolding, oxidative stress, and proteasome activity. Conversely, the influence of cell passage numbers on the proteome is minor, suggesting a reliable range for conducting reproducible biological replicates. Notable, substantial proteome alterations occur over-time post-differentiation of dTHP-1 cells, particularly impacting pathways crucial for macrophage function. This finding is key for the interpretation of experimental results. These results highlight the need for standardized culture conditions in proteomic-based evaluations of treatment effects to ensure reliable results, a prerequisite for achieving regulatory acceptance of proteomics data.

In cell NMR reveals cells selectively amplify and structurally remodel amyloid fibrils.

Amyloid forms of α-synuclein adopt different conformations depending on environmental conditions. Advances in structural biology have accelerated fibril characterization. However, it remains unclear which conformations predominate in biological settings because current methods typically not only require isolating fibrils from their native environments, but they also do not provide insight about flexible regions. To address this, we characterized α-syn amyloid seeds and used sensitivity enhanced nuclear magnetic resonance to investigate the amyloid fibrils resulting from seeded amyloid propagation in different settings. We found that the amyloid fold and conformational preferences of flexible regions are faithfully propagated in vitro and in cellular lysates. However, seeded propagation of amyloids inside cells led to the minority conformation in the seeding population becoming predominant and more ordered, and altered the conformational preferences of flexible regions. The examination of the entire ensemble of protein conformations in biological settings that is made possible with this approach may advance our understanding of protein misfolding disorders and facilitate structure-based drug design efforts.

Screening of Anti-Prion Compounds Using the Protein Misfolding Cyclic Amplification Technology.

Prion diseases are 100% fatal infectious neurodegenerative diseases affecting the brains of humans and other mammals. The disease is caused by the formation and replication of prions, composed exclusively of the misfolded prion protein (PrPSc). We invented and developed the protein misfolding cyclic amplification (PMCA) technology for in vitro prion replication, which allow us to replicate the infectious agent and it is commonly used for ultra-sensitive prion detection in biological fluids, tissues and environmental samples. In this article, we studied whether PMCA can be used to screen for chemical compounds that block prion replication. A small set of compounds previously shown to have anti-prion activity in various systems, mostly using cells infected with murine prions, was evaluated for their ability to prevent the replication of prions. Studies were conducted simultaneously with prions derived from 4 species, including human, cattle, cervid and mouse. Our results show that only one of these compounds (methylene blue) was able to completely inhibit prion replication in all species. Estimation of the IC50 for methylene blue inhibition of human prions causing variant Creutzfeldt-Jakob disease (vCJD) was 7.7 μM. Finally, we showed that PMCA can be used for structure-activity relationship studies of anti-prion compounds. Interestingly, some of the less efficient prion inhibitors altered the replication of prions in some species and not others, suggesting that PMCA is useful for studying the differential selectivity of potential drugs.

Transition Metal Complexes as Therapeutics: A New Frontier in Combatting Neurodegenerative Disorders through Protein Aggregation Modulation.

Neurodegenerative disorders (NDDs) are a class of debilitating diseases that progressively impair the protein structure and result in neurological dysfunction in the nervous system. Among these disorders, Alzheimer's disease (AD), prion diseases such as Creutzfeldt-Jakob disease (CJD), and Parkinson's disease (PD) are caused by protein misfolding and aggregation at the cellular level. In recent years, transition metal complexes have gained significant attention for their potential applications in diagnosing, imaging, and curing these NDDs. These complexes have intriguing possibilities as therapeutics due to their diverse ligand systems and chemical properties and can interact with biological systems with minimal detrimental effects. This review focuses on the recent progress in transition metal therapeutics as a new era of hope in the battle against AD, CJD, and PD by modulating protein aggregation in vitro and in vivo. It may shed revolutionary insights into unlocking new opportunities for researchers to develop metal-based drugs to combat NDDs.

A Review of the Common Neurodegenerative Disorders: Current Therapeutic Approaches and the Potential Role of Bioactive Peptides.

Neurodegenerative disorders, which include Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS), represent a significant and growing global health challenge. Current therapies predominantly focus on symptom management rather than altering disease progression. In this review, we discuss the major therapeutic strategies in practice for these disorders, highlighting their limitations. For AD, the mainstay treatments are cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists. For PD, dopamine replacement therapies, including levodopa, are commonly used. HD is managed primarily with symptomatic treatments, and reusable extends survival in ALS. However, none of these therapies halts or substantially slows the neurodegenerative process. In contrast, this review highlights emerging research into bioactive peptides as potential therapeutic agents. These naturally occurring or synthetically designed molecules can interact with specific cellular targets, potentially modulating disease processes. Preclinical studies suggest that bioactive peptides may mitigate oxidative stress, inflammation, and protein misfolding, which are common pathological features in neurodegenerative diseases. Clinical trials using bioactive peptides for neurodegeneration are limited but show promising initial results. For instance, hemiacetal, a γ-secretase inhibitor peptide, has shown potential in AD by reducing amyloid-beta production, though its development was discontinued due to side effects. Despite these advancements, many challenges remain, including identifying optimal peptides, confirming their mechanisms of action, and overcoming obstacles related to their delivery to the brain. Future research should prioritize the discovery and development of novel bioactive peptides and improve our understanding of their pharmacokinetics and pharmacodynamics. Ultimately, this approach may lead to more effective therapies for neurodegenerative disorders, moving beyond symptom management to potentially modify the course of these devastating diseases.

Molecular mechanism of alpha- and beta-cyclodextrin assisted refolding of SDS-induced amyloid fibrils of myoglobin

The formation of amyloids arises from the misfolding or unfolding of various proteins. This study investigated the impact of chemical chaperones, alpha-cyclodextrin (α-CD) and beta-cyclodextrin (β-CD), on the solubilization and defibrillation of sodium dodecyl sulfate (SDS)-induced myoglobin (Mb) amyloid fibrils. Amyloid fibril was developed in Mb in the presence of 0.8 mmol dm−3 SDS at pH 4.5. Subsequently, SDS-induced Mb amyloid was incubated with varying concentrations of α-CD and β-CD at the same pH. Our turbidity, intrinsic fluorescence, SDS-PAGE, and transmission electron microscope data showed that α-CD (2.1 mmol dm−3) was more efficiently solubilized the SDS-treated Mb aggregates than β-CD (4.0 mmol dm−3). But, another interesting phenomenon was observed with β-CD. The ThT fluorescence and far-UV CD data suggested that amyloid defibrillation by β-CD (0.6 mmol dm−3) was more effective than α-CD (0.9 mmol dm−3). The intrinsic fluorescence and far-UV CD data also showed that SDS-treated Mb regained native-like structure at lower α-CD compared to β-CD. Overall our data suggest that α-CD was more efficient in aggregate solubilization while β-CD was more effective in amyloid defibrillation. Understanding the mechanisms underlying cyclodextrins’ actions may serve as a basis for identifying potential drugs to suppress amyloid fibril formation effectively. This research provides valuable insights into mitigating amyloid-related pathologies.