Metastable condensates suppress conversion to amyloid fibrils.

Stress granules form via co-condensation of RNA binding proteins with prion-like low complexity domains (PLCDs) and RNA molecules released by stress-induced polysomal runoff. Homotypic interactions among PLCDs can drive amyloid fibril formation and this is enhanced by ALS-associated mutations. We find that homotypic interactions that drive condensation versus fibril formation are separable for A1-LCD, the PLCD of hnRNPA1. These separable interactions lead to condensates that are metastable versus fibrils that are globally stable. Metastable condensates suppress fibril formation, and ALS-associated mutations enhance fibril formation by weakening condensate metastability. Mutations designed to enhance A1-LCD condensate metastability restore wild-type behaviors of stress granules in cells even when ALS-associated mutations are present. This suggests that fibril formation can be suppressed by enhancing condensate metastability through condensate-driving interactions.

Investigating zero-state and steady-state performance of MEWMA-CoDa control chart using variable sampling interval.

Traditional process monitoring control charts (CCs) focused on sampling methods using fixed sampling intervals (FSIs). The variable sampling intervals (VSIs) scheme is receiving increasing attention, in which the sampling interval (SI) length varies according to the process monitoring statistics. A shorter SI is considered when the process quality indicates the possibility of an out-of-control (OOC) situation; otherwise, a longer SI is preferred. The VSI multivariate exponentially moving average for compositional data (VSI-MEWMACoDa) CC based on a coordinate representation using isometric log-ratio (ilr) transformation is proposed in this study. A methodology is proposed to obtain the optimal parameters by considering the zero-state (ZS) average time to signal (ZATS) and the steady-state (SS) average time to signal (SATS). The statistical performance of the proposed CC is evaluated based on a continuous-time Markov chain (CTMC) method for both cases, the ZS and the SS using a fixed value of in-control (IC) ATS0. Simulation results demonstrate that the VSI-MEWMACoDa CC has significantly decreased the OOC average time to signal (ATS) than the FSIMEWMACoDa CC. Moreover, it is found that the number of variables (d) has a negative impact on the ATS of the VSI-MEWMACoDa CC, and the subgroup size (n) has a mildly positive impact on the ATS of the VSI-MEWMACoDa CC. At the same time, the SATS of the VSI-MEWMACoDa CC is less than the ZATS of the VSI-MEWMACoDa CC for all the values of n and d. The proposed VSI-MEWMACoDa CC under steady-State performs effectively compared to its competitors, such as the FSI-MEWMACoDa CC, the VSI-T2CoDa CC and the FSI-T2CoDa CC. An example of an industrial problem from a plant in Europe is also given to study the statistical significance of the VSI-MEWMACoDa CC.

Curriculum implementation challenges: Development and validation of an integrated curriculum implementation challenges tool.

Objective: To develop an instrument to identify the challenges faced by faculty while implementing an integrated curriculum in an undergraduate dentistry program. Methods: The study was conducted between September 2020 and October 2021 at the University College of Medicine and Dentistry (UCMD), University of Lahore (UOL). A preliminary questionnaire, developed through literature review and faculty interviews was sent to 10 medical education experts for content validation via the Delphi technique. Content Validity Index (CVI) was calculated for individual items (I-CVI) as well as for the composite scale (S-CVI). A panel agreement of more than 75% was considered as the criterion for the inclusion of items in the questionnaire. Cognitive pretesting of five faculty members was conducted and pilot testing was subsequently done with 27 faculty members. The reliability of the tool was determined by Cronbach's alpha. Results: After the Delphi process, the final Integrated Curriculum Implementation Challenges (ICIC) questionnaire had 42 items. S-CVI was 0.87 and the cut-off value for I-CVI was taken as 0.78 as the criterion for item deletion. Cognitive interviews and pretesting revealed good item interpretation. Cronbach's alpha for this tool was 0.87. Conclusion: ICIC is a useful instrument with good reliability and content validity. It can be used to identify the presence and extent of challenges faced by the faculty while implementing an integrated curriculum.

Dimensions of challenges in transformation from traditional to integrated modular curriculum - Experiences from Pakistan.

Objective: The scarcity of successful implementation of integrated modular curriculum in Pakistan created a lack of evidence-based insight into the process of curriculum transformation. We explored the issue by exploring challenges faced by faculty in implementing integrated modular curriculum. Methods: An exploratory qualitative study was conducted in 2019-2020, data collected from November 2019 to August 2020, at undergraduate medical colleges in Lahore and Rawalpindi, with semi-structured online interviews of well experienced 11 faculty members. Two levels of faculty were sampled; one completed a successful implementation in two medical colleges, and another in transition process. Transcribed interviews were analyzed on Atlas.ti software. Results: Challenges were identified in five inter-connected dimensions: integrated modular curriculum (IMC) development, implementation, faculty transformation/change, institutional and regulatory body context. Conclusion: The curricular shift precipitates demoralizing challenges at multiple levels & directions. The identified themes and connections provide the framework for a well-informed curricular shift.

The Combination of a Human Biomimetic Liver Microphysiology System with BIOLOGXsym, a Quantitative Systems Toxicology (QST) Modeling Platform for Macromolecules, Provides Mechanistic Understanding of Tocilizumab- and GGF2-Induced Liver Injury.

Biologics address a range of unmet clinical needs, but the occurrence of biologics-induced liver injury remains a major challenge. Development of cimaglermin alfa (GGF2) was terminated due to transient elevations in serum aminotransferases and total bilirubin. Tocilizumab has been reported to induce transient aminotransferase elevations, requiring frequent monitoring. To evaluate the clinical risk of biologics-induced liver injury, a novel quantitative systems toxicology modeling platform, BIOLOGXsym™, representing relevant liver biochemistry and the mechanistic effects of biologics on liver pathophysiology, was developed in conjunction with clinically relevant data from a human biomimetic liver microphysiology system. Phenotypic and mechanistic toxicity data and metabolomics analysis from the Liver Acinus Microphysiology System showed that tocilizumab and GGF2 increased high mobility group box 1, indicating hepatic injury and stress. Tocilizumab exposure was associated with increased oxidative stress and extracellular/tissue remodeling, and GGF2 decreased bile acid secretion. BIOLOGXsym simulations, leveraging the in vivo exposure predicted by physiologically-based pharmacokinetic modeling and mechanistic toxicity data from the Liver Acinus Microphysiology System, reproduced the clinically observed liver signals of tocilizumab and GGF2, demonstrating that mechanistic toxicity data from microphysiology systems can be successfully integrated into a quantitative systems toxicology model to identify liabilities of biologics-induced liver injury and provide mechanistic insights into observed liver safety signals.

Tracheostomy in children is associated with neutrophilic airway inflammation.

BACKGROUND: Tracheostomies in children are associated with significant morbidity, poor quality of life, excess healthcare costs and excess mortality. The underlying mechanisms facilitating adverse respiratory outcomes in tracheostomised children are poorly understood. We aimed to characterise airway host defence in tracheostomised children using serial molecular analyses. METHODS: Tracheal aspirates, tracheal cytology brushings and nasal swabs were prospectively collected from children with a tracheostomy and controls. Transcriptomic, proteomic and metabolomic methods were applied to characterise the impact of tracheostomy on host immune response and the airway microbiome. RESULTS: Children followed up serially from the time of tracheostomy up to 3 months postprocedure (n=9) were studied. A further cohort of children with a long-term tracheostomy were also enrolled (n=24). Controls (n=13) comprised children without a tracheostomy undergoing bronchoscopy. Long-term tracheostomy was associated with airway neutrophilic inflammation, superoxide production and evidence of proteolysis when compared with controls. Reduced airway microbial diversity was established pre-tracheostomy and sustained thereafter. CONCLUSIONS: Long-term childhood tracheostomy is associated with a inflammatory tracheal phenotype characterised by neutrophilic inflammation and the ongoing presence of potential respiratory pathogens. These findings suggest neutrophil recruitment and activation as potential exploratory targets in seeking to prevent recurrent airway complications in this vulnerable group of patients.

Two polyphenols with diverse mechanisms towards amyloidosis: differential modulation of the fibrillation pathway of human lysozyme by curcumin and EGCG.

The effect of two widely used polyphenols, curcumin and EGCG was investigated on the amyloid fibrillogenesis of the well-characterized model protein human lysozyme (HuL), associated with non-neuropathic systemic amyloidosis, towards exploring their efficacy as modulators of HuL amyloid aggregation and toxicity and unravelling their mechanism of action. Curcumin exerts its inhibitory influence towards HuL fibrillation by interacting with the prefibrillar and fibrillar intermediates resulting in complete suppression of fibrillation at ∼200 µM and effectively disaggregates preformed fibrils of HuL. EGCG on the other hand suppresses fibrillation only upto 70% at ∼400 µM, modulates the pathway towards large, ß-sheet rich amyloid fibril-like aggregates and modifies the preformed fibrils into similar type of large, clustered aggregate assemblies. The overall surface hydrophobicity and cytotoxicity of HuL is significantly reduced not only in the presence of curcumin but also EGCG, despite the latter forming large agglomerates, which could be accounted for by the dense and highly clustered nature of aggregates rendering their surface less exposed and thus less amenable to interact with cellular entities thereby causing reduced cellular toxicity. This study highlights the differential mechanisms employed by curcumin and ECCG in modulating the fibrillation pathway of HuL and illustrates the importance of overall modulation of fibrillation towards a general reduction in toxicity, rather than specifically focusing only on inhibition of fibrillation. This study also demonstrates how two widely different polyphenols employ disparate mechanisms to modulate the fibrillation pathway of a single protein and yet converge towards a common effect of alleviation of cytotoxicity.

Assessment of burnout and associated factors among medical educators.

OBJECTIVE: To assess burnout in medical educators and to identify factors associated with it. METHODS: A sequential mixed methods research study was conducted over eight months from July 2018 until February 2019. Participants included medical educators, who are studying for or graduated with a postgraduate qualification in medical education. An online questionnaire was developed using Maslach Burnout Inventory to collect quantitative data. The findings were explored in-depth qualitatively. Descriptive and inferential statistics were calculated for the quantitative data using SPSS 20. For qualitative data, we performed thematic analysis. RESULTS: Of total 160 medical educationists, 101 responded giving 63.1% response rate. Mean age was 41.4 years and majority 53.5% were females. Overall aggregate mean burnout level was 12.34 ± 7.36 whereas sub-domains of Maslach burnout inventory (MBI) like i) emotional exhaustion, ii) depersonalization and iii) personal accomplishment were found out to be 19.59, 10.42 and 11.21 respectively. Most respondents had moderate 71 (70.3%) emotional exhaustion and 8 (8.9%) had severe emotional exhaustion. Average level of depersonalization was suffered by 73 (72.3%) respondents and severe level was observed in 20 (19.8%) respondents. Personal accomplishment was found low in all 101 (100.0%) respondents. Selective in-depth interviews revealed that coping mechanisms like social gatherings, indoor and outdoor game facilities and outings and leisure time should be strategized for faculties. CONCLUSION: In this study medical educators were found to have quite high level of burnout. The early career medical educators feels emotionally exhausted, with low sense of personal accomplishment.

VOC fingerprints: metabolomic signatures of biothreat agents with and without antibiotic resistance.

Category A and B biothreat agents are deemed to be of great concern by the US Centers for Disease Control and Prevention (CDC) and include the bacteria Francisella tularensis, Yersinia pestis, Burkholderia mallei, and Brucella species. Underscored by the impact of the 2020 SARS-CoV-2 outbreak, 2016 Zika pandemic, 2014 Ebola outbreak, 2001 anthrax letter attacks, and 1984 Rajneeshee Salmonella attacks, the threat of future epidemics/pandemics and/or terrorist/criminal use of pathogenic organisms warrants continued exploration and development of both classic and alternative methods of detecting biothreat agents. Volatile organic compounds (VOCs) comprise a large and highly diverse group of carbon-based molecules, generally related by their volatility at ambient temperature. Recently, the diagnostic potential of VOCs has been realized, as correlations between the microbial VOC metabolome and specific bacterial pathogens have been identified. Herein, we describe the use of microbial VOC profiles as fingerprints for the identification of biothreat-relevant microbes, and for differentiating between a kanamycin susceptible and resistant strain. Additionally, we demonstrate microbial VOC profiling using a rapid-throughput VOC metabolomics method we refer to as 'simultaneous multifiber headspace solid-phase microextraction' (simulti-hSPME). Finally, through VOC analysis, we illustrate a rapid non-invasive approach to the diagnosis of BALB/c mice infected with either F. tularensis SCHU S4 or Y. pestis CO92.

Scutellarin inhibits the uninduced and metal-induced aggregation of α-Synuclein and disaggregates preformed fibrils: implications for Parkinson's disease.

The aggregation of the protein alpha synuclein (α-Syn), a known contributor in Parkinson's disease (PD) pathogenesis is triggered by transition metal ions through occupational exposure and disrupted metal ion homeostasis. Naturally occurring small molecules such as polyphenols have emerged as promising inhibitors of α-Syn fibrillation and toxicity and could be potential therapeutic agents against PD. Here, using an array of biophysical tools combined with cellular assays, we demonstrate that the novel polyphenolic compound scutellarin efficiently inhibits the uninduced and metal-induced fibrillation of α-Syn by acting at the nucleation stage and stabilizes a partially folded intermediate of α-Syn to form SDS-resistant, higher-order oligomers (∼680 kDa) and also disaggregates preformed fibrils of α-Syn into similar type of higher-order oligomers. ANS binding assay, fluorescence lifetime measurements and cell-toxicity experiments reveal scutellarin-generated oligomers as compact, low hydrophobicity structures with modulated surface properties and significantly reduced cytotoxicity than the fibrillation intermediates of α-Syn control. Fluorescence spectroscopy and isothermal titration calorimetry establish the binding between scutellarin and α-Syn to be non-covalent in nature and of moderate affinity (Ka ∼ 105 M-1). Molecular docking approaches suggest binding of scutellarin to the residues present in the NAC region and C-terminus of monomeric α-Syn and the C-terminal residues of fibrillar α-Syn, demonstrating inhibition of fibrillation upon binding to these residues and possible stabilization of the autoinhibitory conformation of α-Syn. These findings reveal interesting insights into the mechanism of scutellarin action and establish it as an efficient modulator of uninduced as well as metal-induced α-Syn fibrillation and toxicity.

Association of vitamin D levels with preeclampsia.

OBJECTIVE: This study was aimed to assess maternal vitamin D status during pregnancy and determine the association between maternal 25(OH) D levels with risk of preeclampsia (PE). METHODS: A cross-sectional study was conducted with 172 pregnant women recruited from JPMC between January and December 2017 who were divided as normotensive (n=80) and pre eclamptic (n=92) groups. Blood pressure was recorded at 20 and 32 weeks of gestation. Five ml of blood sample was collected at 20 weeks of gestation to assess the vitamin D levels by commercially available ELISA assay. RESULTS: PE group had a significantly higher systolic (p<0.001) and diastolic (p<0.001) blood pressure at 20 weeks of gestation. Vitamin D levels were reported to be significantly lower (p<0.001) in the PE group (17.97±9.38 ng/ml) as compared to normotensive group (42.18±25.17 ng/ml). A strong negative correlation of Vitamin D levels with systolic blood pressure (r=-0.428; p<0.001) and diastolic blood pressure (r= 0.375; p<0.001) was found. CONCLUSIONS: This study found a strong relationship between low vitamin D levels and pre-eclamptic manifestation.

COVID-19 and Palliative Care Services: Comparative Patterns of Inpatient, Outpatient, and Consultation Services in a Tertiary Care Center in Riyadh.

Introduction The coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) marked the third introduction of a highly pathogenic and large-scale epidemic coronavirus into the human population in the 21st century. The World Health Organization declared the COVID-19 outbreak as a pandemic on March 11, 2020. Lockdowns were imposed in multiple countries affecting patient flow in hospitals. Methods This is a retrospective study conducted at King Fahad Medical City (KFMC), a tertiary care hospital in Riyadh, Saudi Arabia, which examined the differences in palliative care services during the initial four months of the COVID-19 pandemic compared to the respective four months in 2019 (March, April, May, June). Results A total of 319 patients were seen at the palliative care department from March to June 2020 during the COVID-19 pandemic (119 inpatient, 200 outpatient), compared to 346 patients seen during the corresponding months in 2019 (97 inpatient, 249 outpatient). Our main findings included more patients being discharged home, lesser transfers, shorter hospital length of stay, lesser imminent death protocols, and a higher palliative performance score (PPS) during the COVID-19 pandemic. Although there were more cancelations by the hospital for the outpatient department, a virtual clinic was started, and 84 patients were effectively seen. Around 87% of patients were fully satisfied (5/5) with the services provided by the virtual clinic. There were no positive COVID-19 cases in our healthcare workers in the palliative care department due to the high standard precautions applied at KFMC. Family meetings as well as administrative and academic meetings have been efficiently held virtually and may possibly become the standard of practice. Conclusion Palliative care services were successfully maintained during the COVID-19 pandemic at KFMC.

Resveratrol Interferes with an Early Step in the Fibrillization Pathway of Human Lysozyme and Modulates it towards Less-Toxic, Off-Pathway Aggregates.

The effect of resveratrol, a polyphenol in red wine, on the amyloid fibril formation of human lysozyme (HuL) was investigated, towards elucidating the mechanism of resveratrol action and probing its role as a possible modulator of lysozyme aggregation and toxicity. By using a number of biophysical tools, resveratrol was observed to alter the fibrillization kinetics of HuL and inhibit its fibrillization by binding with weak to moderate affinity to the conformations populated at the early stages of the pathway with concomitant stabilization of these initial conformations. The marginal decrease in the lifetime of HuL in the presence of resveratrol by time-resolved fluorescence measurements indicated the involvement of a static quenching mechanism in the interaction between HuL and resveratrol. Docking studies predicted the binding of resveratrol to aggregation-prone regions in HuL, and structure and activity analyses demonstrated the retention of much of the α-helical structure and activity of HuL in the presence of resveratrol. Resveratrol modulated the fibrillization pathway towards less-hydrophobic, less-toxic, off-pathway aggregates. These results demonstrate that binding of resveratrol to HuL could protect against the formation of pathogenic, cytotoxic aggregates formed in amyloidogenic disorders, such as systemic amyloidosis; thus suggesting its potential as a plausible therapeutic agent against lysozyme amyloidosis.

Urine lipoarabinomannan glycan in HIV-negative patients with pulmonary tuberculosis correlates with disease severity.

An accurate urine test for pulmonary tuberculosis (TB), affecting 9.6 million patients worldwide, is critically needed for surveillance and treatment management. Past attempts failed to reliably detect the mycobacterial glycan antigen lipoarabinomannan (LAM), a marker of active TB, in HIV-negative, pulmonary TB-infected patients' urine (85% of 9.6 million patients). We apply a copper complex dye within a hydrogel nanocage that captures LAM with very high affinity, displacing interfering urine proteins. The technology was applied to study pretreatment urine from 48 Peruvian patients, all negative for HIV, with microbiologically confirmed active pulmonary TB. LAM was quantitatively measured in the urine with a sensitivity of >95% and a specificity of >80% (n = 101) in a concentration range of 14 to 2000 picograms per milliliter, as compared to non-TB, healthy and diseased, age-matched controls (evaluated by receiver operating characteristic analysis; area under the curve, 0.95; 95% confidence interval, 0.9005 to 0.9957). Urinary LAM was elevated in patients with a higher mycobacterial burden (n = 42), a higher proportion of weight loss (n = 37), or cough (n = 50). The technology can be configured in a variety of formats to detect a panel of previously undetectable very-low-abundance TB urinary analytes. Eight of nine patients who were smear-negative and culture-positive for TB tested positive for urinary LAM. This technology has broad implications for pulmonary TB screening, transmission control, and treatment management for HIV-negative patients.

What are farmers really planting? Measuring the presence and effectiveness of Bt cotton in Pakistan.

Genetically modified, insect-resistant Bacillus thuringiensis (Bt) cotton is cultivated extensively in Pakistan. Past studies, however, have raised concerns about the prevalence of Bt cotton varieties possessing weak or nonperforming insect-resistance traits conferred by the cry gene. We examine this issue using data drawn from a representative sample of cotton-growing households that were surveyed in six agroclimatic zones spanning 28 districts in Pakistan in 2013, as well as measurements of Cry protein levels in cotton tissue samples collected from the sampled households' main fields. The resultant dataset combines information from 593 sampled households with corresponding plant tissue diagnostics from 70 days after sowing, as well as information from 589 sampled households with corresponding diagnostics from 120 days after sowing. Our analysis indicates that 11 percent of farmers believed they were cultivating Bt cotton when, in fact, the Cry toxin was not present in the tested tissue at 70 days after sowing (i.e., a Type I error). The analysis further indicates that 5 percent of farmers believed they were cultivating non-Bt cotton when, in fact, the Cry toxin was present in the tested tissue (i.e., a Type II error). In addition, 17 percent of all sampled farmers were uncertain whether or not they were cultivating Bt cotton. Overall, 33 percent of farmers either did not know or were mistaken in their beliefs about the presence of the cry gene in the cotton they cultivated. Results also indicate that toxic protein levels in the plant tissue samples occurred below threshold levels for lethality in a significant percentage of cases, although these measurements may also be affected by factors related to tissue sample collection, handling, storage, and testing procedures. Nonetheless, results strongly suggest wide variability both in farmers' beliefs and in gene expression. Such variability has implications for policy and regulation in Pakistan's transgenic cotton seed market.

Alcohol induced alterations to the human fecal VOC metabolome.

Studies have shown that excessive alcohol consumption impacts the intestinal microbiota composition, causing disruption of homeostasis (dysbiosis). However, this observed change is not indicative of the dysbiotic intestinal microbiota function that could result in the production of injurious and toxic products. Thus, knowledge of the effects of alcohol on the intestinal microbiota function and their metabolites is warranted, in order to better understand the role of the intestinal microbiota in alcohol associated organ failure. Here, we report the results of a differential metabolomic analysis comparing volatile organic compounds (VOC) detected in the stool of alcoholics and non-alcoholic healthy controls. We performed the analysis with fecal samples collected after passage as well as with samples collected directly from the sigmoid lumen. Regardless of the approach to fecal collection, we found a stool VOC metabolomic signature in alcoholics that is different from healthy controls. The most notable metabolite alterations in the alcoholic samples include: (1) an elevation in the oxidative stress biomarker tetradecane; (2) a decrease in five fatty alcohols with anti-oxidant property; (3) a decrease in the short chain fatty acids propionate and isobutyrate, important in maintaining intestinal epithelial cell health and barrier integrity; (4) a decrease in alcohol consumption natural suppressant caryophyllene; (5) a decrease in natural product and hepatic steatosis attenuator camphene; and (6) decreased dimethyl disulfide and dimethyl trisulfide, microbial products of decomposition. Our results showed that intestinal microbiota function is altered in alcoholics which might promote alcohol associated pathologies.

Significantly enhanced heme retention ability of myoglobin engineered to mimic the third covalent linkage by nonaxial histidine to heme (vinyl) in synechocystis hemoglobin.

Heme proteins, which reversibly bind oxygen and display a particular fold originally identified in myoglobin (Mb), characterize the "hemoglobin (Hb) superfamily." The long known and widely investigated Hb superfamily, however, has been enriched by the discovery and investigation of new classes and members. Truncated Hbs typify such novel classes and exhibit a distinct two-on-two α-helical fold. The truncated Hb from the freshwater cyanobacterium Synechocystis exhibits hexacoordinate heme chemistry and bears an unusual covalent bond between the nonaxial His(117) and a heme porphyrin 2-vinyl atom, which remains tightly associated with the globin unlike any other. It seems to be the most stable Hb known to date, and His(117) is the dominant force holding the heme. Mutations of amino acid residues in the vicinity did not influence this covalent linkage. Introduction of a nonaxial His into sperm whale Mb at the topologically equivalent position and in close proximity to vinyl group significantly increased the heme stability of this prototype globin. Reversed phase chromatography, electrospray ionization-MS, and MALDI-TOF analyses confirmed the presence of covalent linkage in Mb I107H. The Mb mutant with the engineered covalent linkage was stable to denaturants and exhibited ligand binding and auto-oxidation rates similar to the wild type protein. This indeed is a novel finding and provides a new perspective to the evolution of Hbs. The successful attempt at engineering heme stability holds promise for the production of stable Hb-based blood substitute.

pH-dependent differential interacting mechanisms of sodium dodecyl sulfate with bovine serum fetuin: a biophysical insight.

Sodium dodecyl sulfate (SDS)-glycoprotein interaction serves as a model for a biological membrane. To get mechanistic insight into the interaction of SDS and glycoprotein, the effect of SDS on bovine serum fetuin (BSF) was studied in subcritical micellar concentrations at pH 7.4 and pH 2 using multiple approaches. SDS interacts electrostatically with BSF through its negatively charged head groups at pH 2 and hydrophobically via its alkyl chains at pH 7.4 up to a 1:20 molar ratio of BSF to SDS. However, at higher concentrations of SDS, BSF undergoes amyloid fibril formation at pH 2, as confirmed by enhanced ThT fluorescence, ß-sheet formation, and TEM microscopy, whereas BSF undergoes induction of an α-helical structure in the presence of higher SDS concentration at pH 7.4. The increase in α-helical content with increasing SDS concentrations constrains the environment around tryptophan. As a consequence, the interconversion of tryptophan conformers decreases, resulting in a decrement of the fluorescence lifetime for BSF in the presence of SDS at pH 7.4.