TB PCR in BAL and EBUS-TBNA samples for the diagnosis of pulmonary and mediastinal lymph node TB: retrospective TRiBE study.

INTRODUCTION: The role of Xpert Ultra in bronchoalveolar lavage (BAL) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples for pulmonary and mediastinal lymph node tuberculosis (TB) remains unclear. METHODS: This was a retrospective observational service evaluation at a tertiary TB centre in a low-incidence setting. The diagnostic indices of Xpert Ultra, smear and culture (with cytology for EBUS-TBNA samples) were compared with culture positivity or a composite reference standard of clinical TB diagnosis. Trace readouts, a new category of results for Xpert Ultra indicating low bacillary load, were analysed in two ways as a true positive or true negative result. 282 BAL and 139 EBUS-TBNA samples were included in the analysis. RESULTS: BAL: sensitivity with 95% CI against culture-confirmed pulmonary TB from BAL samples for Xpert Ultra (trace as positive) was 0.91 (0.82 to 0.98), Xpert Ultra (trace as negative) was 0.76 (0.69 to 0.83), smear was 0.38 (p=0.0009) and culture was 1.00 (0.91 to 1.00). Specificities for all the tests were ≥0.99 (0.98 to 1.00). The addition of smear to Xpert Ultra did not improve the diagnostic accuracy.EBUS-TBNA: sensitivity against culture-confirmed TB from EBUS-TBNA samples for Xpert Ultra (trace as positive) was 0.71 (0.63 to 0.78), Xpert Ultra (trace as negative) was 0.59 (0.54 to 0.63), smear was 0.12 (p=0.002), culture was 1.00 (0.89 to 1.00), cytology was 0.87 (0.76 to 0.98) and rapid on-site evaluation of cytology (ROSE) was 0.92 (0.78 to 1.00). Specificities were 0.99 (0.97 to 1.00), 0.99 (0.97 to 1.00), 1.00 (0.98 to 1.00), 1.00 (0.98 to 1.00), 0.67 (0.67 to 0.68) and 0.42, respectively. CONCLUSION: Xpert Ultra had a significantly higher sensitivity compared with smear in both BAL and EBUS-TBNA samples. Xpert Ultra had a lower sensitivity compared with culture but comparable specificity with results being available within <24 hours. Trace readings in our low-incidence setting were associated with culture positivity in all BAL samples.

Cytarabine induces cachexia with lipid malabsorption via zippering the junctions of lacteal in murine small intestine.

Chemotherapy-induced cachexia causes severe metabolic abnormalities independently of cancer and reduces the therapeutic efficacy of chemotherapy. The underlying mechanism of chemotherapy-induced cachexia remains unclear. Here we investigated the cytarabine (CYT)-induced alteration in energy balance and its underlying mechanisms in mice. We compared energy balance-associated parameters among the three groups of mice: CON, CYT, and PF (pair-fed mice with the CYT group) that were intravenously administered vehicle or CYT. Weight gain, fat mass, skeletal muscle mass, grip strength, and nocturnal energy expenditure were significantly lowered in the CYT group than in the CON and PF groups. The CYT group demonstrated less energy intake than the CON group and higher respiratory quotient than the PF group, indicating that CYT induced cachexia independently from the anorexia-induced weight loss. Serum triglyceride was significantly lower in the CYT group than in the CON group, whereas the intestinal mucosal triglyceride levels and the lipid content within the small intestine enterocyte were higher after lipid loading in the CYT group than in the CON and PF groups, suggesting that CYT inhibited lipid uptake in the intestine. This was not associated with obvious intestinal damage. The CYT group showed increased zipper-like junctions of lymphatic endothelial vessel in duodenal villi compared to that in the CON and CYT groups, suggesting their imperative role in the CYT-induced inhibition of lipid uptake. CYT worsens cachexia independently of anorexia by inhibiting the intestinal lipid uptake, via the increased zipper-like junctions of lymphatic endothelial vessel.

Background free in vivo29Si MR imaging with hyperpolarized PEGylated silicon nanoparticles.

This study demonstrated the potential of 50 nm PEGylated Si NPs for high-resolution in vivo29Si MR imaging, emphasizing their biocompatibility and water dispersibility. The acquisition of in vivo Si MR images using the lowest reported dose after subcutaneous and intraperitoneal administration opens new avenues for future 29Si MR studies.

Monitoring energy balance through clinical and serum biomarkers in patients with hematologic malignancies undergoing chemotherapy.

Despite widespread concern about energy imbalance due to tumor and chemotherapy-related side effects, little is known about detailed variations in energy input, metabolic rate, and physical activity. This study explored changes in energy balance components and serum biomarkers of patients with hematologic malignancies undergoing chemotherapy. Our prospective study included 40 patients with hematologic malignancies hospitalized for chemotherapy. We measured energy balance components, physical function, and serum biomarkers at baseline and weekly after chemotherapy for 3 weeks. Significant weight loss, representing negative energy balance, occurred at 2 (p = 0.002) and 3 weeks (p < 0.001) post-chemotherapy. Statistically reduced oral intake was observed at 3 weeks post-chemotherapy (p = 0.040), and resting energy expenditure statistically decreased according to Harris-Benedict equation, but not to Penn State University equation. Physical function according to DEMMI score decreased significantly at 3 weeks post-chemotherapy (p = 0.002). Serum biomarker analysis demonstrated significant changes in albumin, total protein, CXCL13, and GDF15, with exception of leptin. Although conventional serum biomarkers (total protein and albumin) did not reach pathological states despite their statistical differences, subgroup analysis showed CXCL13 in weight loss group and GDF15 in reduced oral intake group were significantly changed. Over half of patients (65.0%, n = 26) suffered from energy imbalance associated with weight loss and reduced oral intake during chemotherapy. Serial laboratory results suggested that novel biomarkers (CXCL13, GDF15) could be correlated with cachexic state and reduced food intake. Monitoring clinical and serum biomarkers associated with energy balance together can help identify needs for nutritional support in patients with hematologic malignancies undergoing chemotherapy.

Evaluating the clinical impact of routine whole genome sequencing in tuberculosis treatment decisions and the issue of isoniazid mono-resistance.

BACKGROUND: The UK has implemented routine use of whole genome sequencing (WGS) in TB diagnostics. The WHO recommends addition of a fluoroquinolone for isoniazid mono-resistance, so early detection may be of use. The aim of this study was to describe the clinical utility and impact of WGS on treatment decisions for TB in a low incidence high resource clinical setting. The clinical turnaround time (TAT) for WGS was analysed in comparison to TB PCR using Xpert MTB/RIF (Cepheid, Sunnyvale, CA) results where available and subsequent phenotypic drug susceptibility testing (DST) when required. METHODS: This was a retrospective analysis of TB cases from January 2018 to March 2019 in London. Susceptibility and TAT by WGS, phenotypic DST, TB PCR using Xpert MTB/RIF were correlated to drug changes in order to describe the utility of WGS on treatment decisions on isoniazid mono-resistance in a low incidence high resource setting. RESULTS: 189 TB cases were identified; median age 44 years (IQR 28-60), m:f ratio 112:77, 7 with HIV and 6 with previous TB. 80/189 cases had a positive culture and WGS result. 50/80 were fully sensitive to 1st line treatment on WGS, and the rest required additional DST. 20/80 cases required drug changes; 12 were defined by WGS: 8 cases had isoniazid mono-resistance, 2 had MDR-TB, 1 had isoniazid and pyrazinamide resistance and 1 had ethambutol resistance. The median TAT for positive culture was 16 days (IQR 12.5-20.5); for WGS was 35 days (IQR 29.5-38.75) and for subsequent DST was 86 days (IQR 69.5-96.75), resulting in non-WHO regimens for a median of 50.5 days (IQR 28.0-65.0). 9/12 has TB PCRs (Xpert MTB/RIF), with a median TAT of 1 day. CONCLUSION: WGS clearly has a substantial role in our routine UK clinical settings with faster turnaround times in comparison to phenotypic DST. However, the majority of treatment changes defined by WGS were related to isoniazid resistance and given the 1 month TAT for WGS, it would be preferable to identify isoniazid resistance more quickly. Therefore if resources allow, diagnostic pathways should be optimised by parallel use of WGS and new molecular tests to rapidly identify isoniazid resistance in addition to rifampicin resistance and to minimise delays in starting WHO isoniazid resistance treatment.

Deletion of adipose triglyceride lipase abolishes blood flow increase after ß3-adrenergic stimulation in visceral adipose tissue of mice.

Dynamic changes in adipose tissue blood flow (ATBF) with nutritional status play a role in the regulation of metabolic and endocrine functions. Activation of the sympathetic nervous system via ß-adrenergic receptors (ß-AR) contributes to the control of postprandial enhancement of ATBF. Herein, we sought to identify the role of each ß-AR subtype in the regulation of ATBF in mice. We monitored the changes in visceral epididymal ATBF (VAT BF), induced by local infusion of dobutamine, salbutamol, and CL316,243 (a selective ß1-, ß2-, and ß3-AR agonist, respectively) into VAT of lean CD-1 mice and global adipose triglyceride lipase (ATGL) knockout (KO) mice, using laser Doppler flowmetry. Administration of CL316,243, known to promote lipolysis in adipocytes, significantly increased VAT BF of CD-1 mice to a greater extent compared to that of the vehicle, whereas administration of dobutamine or salbutamol did not produce significant differences in VAT BF. The increase in VAT BF induced by ß3-AR stimulation disappeared in ATGL KO mice as opposed to their wild-type (WT) littermates, implying a role of ATGL-mediated lipolysis in the regulation of VAT BF. Different vascular reactivities occurred despite no significant differences in vessel density and adiposity between the groups. Additionally, the expression levels of the angiogenesis-related genes were significantly higher in VAT of ATGL KO mice than in that of WT, implicating an association of ATBF responsiveness with angiogenic activity in VAT. Our findings suggest a potential role of ß3-AR signaling in the regulation of VAT BF via ATGL-mediated lipolysis in mice.

Improving the diagnosis of tuberculosis: old and new laboratory tools.

INTRODUCTION: Despite recent advances in diagnostic technologies and new drugs becoming available, tuberculosis (TB) remains a major global health burden. If detected early, screened for drug resistance, and fully treated, TB could be easily controlled. AREAS COVERED: Here the authors discuss M. tuberculosis culture methods which are considered the definitive confirmation of M. tuberculosis infection, and limited advances made to build on these core elements of TB laboratory diagnosis. Literature searches showed that molecular techniques provide enhanced speed of turnaround, sensitivity, and richness of data. Sequencing of the whole genome, is becoming well established for identification and inference of drug resistance. PubMed® literature searches were conducted (November 2022-March 2024). EXPERT OPINION: This section highlights future advances in diagnosis and infection control. Prevention of prolonged hospital admissions and rapid TAT are of the most benefit to the overall patient experience. Host transcriptional blood markers have been used in treatment monitoring studies and, with appropriate evaluation, could be rolled out in a diagnostic setting. Additionally, the MBLA is being incorporated into latest clinical trial designs. Whole genome sequencing has enhanced epidemiological evidence. Artificial intelligence, along with machine learning, have the ability to revolutionize TB diagnosis and susceptibility testing within the next decade.

Human IgA-binding peptides selected from random peptide libraries: affinity maturation and application in IgA purification.

Phage display system is a powerful tool to design specific ligands for target molecules. Here, we used disulfide-constrained random peptide libraries constructed with the T7 phage display system to isolate peptides specific to human IgA. The binding clones (A1-A4) isolated by biopanning exhibited clear specificity to human IgA, but the synthetic peptide derived from the A2 clone exhibited a low specificity/affinity (K(d) = 1.3 µm). Therefore, we tried to improve the peptide using a partial randomized phage display library and mutational studies on the synthetic peptides. The designed Opt-1 peptide exhibited a 39-fold higher affinity (K(d) = 33 nm) than the A2 peptide. An Opt-1 peptide-conjugated column was used to purify IgA from human plasma. However, the recovered IgA fraction was contaminated with other proteins, indicating nonspecific binding. To design a peptide with increased binding specificity, we examined the structural features of Opt-1 and the Opt-1-IgA complex using all-atom molecular dynamics simulations with explicit water. The simulation results revealed that the Opt-1 peptide displayed partial helicity in the N-terminal region and possessed a hydrophobic cluster that played a significant role in tight binding with IgA-Fc. However, these hydrophobic residues of Opt-1 may contribute to nonspecific binding with other proteins. To increase binding specificity, we introduced several mutations in the hydrophobic residues of Opt-1. The resultant Opt-3 peptide exhibited high specificity and high binding affinity for IgA, leading to successful isolation of IgA without contamination.

ERS International Congress 2022: highlights from the Respiratory Infections Assembly.

The European Respiratory Society International Congress took place both in person, in Barcelona, Spain, and online in 2022. The congress welcomed over 19 000 attendees on this hybrid platform, bringing together exciting updates in respiratory science and medicine from around the world. In this article, Early Career Members of the Respiratory Infections Assembly (Assembly 10) summarise a selection of sessions across a broad range of topics, including presentations on bronchiectasis, nontuberculous mycobacteria, tuberculosis, cystic fibrosis and coronavirus disease 2019.

Inhibition of adipose tissue angiogenesis prevents rebound weight gain after caloric restriction in mice fed a high-fat diet.

AIMS: We investigated whether modulation of white adipose tissue (WAT) vasculature regulates rebound weight gain (RWG) after caloric restriction (CR) in mice fed a high-fat diet (HFD). MAIN METHODS: We compared changes in energy balance, hypothalamic neuropeptide gene expression, and characteristics of WAT by RT-qPCR, ELISA, immunohistochemistry, and adipose-derived stromal vascular fraction spheroid sprouting assay in obese mice fed a HFD ad libitum (HFD-AL), mice under 40 % CR for 3 or 4 weeks, mice fed HFD-AL for 3 days after CR (CRAL), and CRAL mice treated with TNP-470, an angiogenic inhibitor. KEY FINDINGS: WAT angiogenic genes were expressed at low levels, but WAT vascular density was maintained in the CR group compared to that in the HFD-AL group. The CRAL group showed RWG, fat regain, and hyperphagia with higher expression of angiogenic genes and reduced pericyte coverage of the endothelium in WAT on day 3 after CR compared to the CR group, indicating rapidly increased angiogenic activity after CR. Administration of TNP-470 suppressed RWG, fat regain, and hyperphagia only after CR compared to the CRAL group. Changes in circulating leptin levels and hypothalamic neuropeptide gene expression were correlated with changes in weight and fat mass, suggesting that TNP-470 suppressed hyperphagia independently of the hypothalamic melanocortin system. Additionally, TNP-470 increased gene expression related to thermogenesis, fuel utilization, and browning in brown adipose tissue (BAT) and WAT, indicating TNP-470-induced increase in thermogenesis. SIGNIFICANCE: Modulation of the WAT vasculature attenuates RWG after CR by suppressing hyperphagia and increasing BAT thermogenesis and WAT browning.

Ptychographic lens-less birefringence microscopy using a mask-modulated polarization image sensor.

Birefringence, an inherent characteristic of optically anisotropic materials, is widely utilized in various imaging applications ranging from material characterizations to clinical diagnosis. Polarized light microscopy enables high-resolution, high-contrast imaging of optically anisotropic specimens, but it is associated with mechanical rotations of polarizer/analyzer and relatively complex optical designs. Here, we present a form of lens-less polarization-sensitive microscopy capable of complex and birefringence imaging of transparent objects without an optical lens and any moving parts. Our method exploits an optical mask-modulated polarization image sensor and single-input-state LED illumination design to obtain complex and birefringence images of the object via ptychographic phase retrieval. Using a camera with a pixel size of 3.45 µm, the method achieves birefringence imaging with a half-pitch resolution of 2.46 µm over a 59.74 mm2 field-of-view, which corresponds to a space-bandwidth product of 9.9 megapixels. We demonstrate the high-resolution, large-area, phase and birefringence imaging capability of our method by presenting the phase and birefringence images of various anisotropic objects, including a monosodium urate crystal, and excised mouse eye and heart tissues.

Elution-free DNA detection using CRISPR/Cas9-mediated light-up aptamer transcription: Toward all-in-one DNA purification and detection tube.

Accurate and efficient detection of DNA is crucial for disease diagnosis and health monitoring. The traditional methods for DNA analysis involve multiple steps, including sample preparation, lysis, extraction, amplification, and detection. In this study, we present a one-step elution-free DNA analysis method based on the combination of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated light-up aptamer transcription (CLAT) assay and a DNA-capturing poly(2-dimethylaminomethyl styrene) (pDMAMS)-coated tube. The sample solution and lysis buffer are added to the pDMAMS-coated tube, and the DNA is efficiently captured on the surface via electrostatic interaction and directly detected by CLAT assay. The ability of the CRISPR/Cas9 system to specifically recognize DNA enables direct detection of DNA captured on the pDMAMS-coated tube. The combination of CLAT assay and pDMAMS-coated tube simplifies DNA detection in a single tube without the need for complicated extraction steps, improving sensitivity. Our platform demonstrated attomolar sensitivity in the detection of target DNA in cell lysate (0.92 aM), urine (7.7 aM), and plasma (94.6 aM) samples within 1 h. The practical applicability of this method was further demonstrated in experiments with tumor-bearing mice. We believe that this approach brings us closer to an all-in-one DNA purification and detection tube system and has potential applications in tissue and liquid biopsies, as well as various other DNA sensing applications.

Electrocardiographic abnormalities in medically screened military aircrew.

BACKGROUND: The European Society of Cardiology (ESC) recently published its updated recommendations for electrocardiogram (ECG) interpretation in athletes. It distinguishes ECG changes related to physical training (group 1 abnormalities) from training-unrelated changes (group 2) which may represent underlying electrical and structural heart disorders implicated in exercise related sudden cardiac death. This study sought to prospectively apply the ESC screening criteria to a large cohort of screened military aircrew. METHODS: This was a prospective observational study. The 12-lead ECGs of 868 consecutively evaluated healthy aircrew were analyzed for the presence of ESC-defined group 1 and 2 abnormalities. RESULTS: The average age was 39.6 (11.2) yr (95.4% male). Overall, 402 (46.3%) of ECGs could be classified as entirely normal. However, 466 ECGs (53.7%) were abnormal. Group 1 abnormalities were identified in 400 (46.1%) persons with 66 (7.6%) persons classified as having group 2 abnormalities. The most commonly identified group 1 ECG changes were sinus bradycardia (32.5%), early repolarization (11.8%), and isolated voltage criteria of left ventricular hypertrophy (10.1%). The most commonly noted group 2 abnormalities were left-axis deviation/left anterior hemiblock (2.4%), T-wave inversion (1.6%), and ST-segment depression (1.3%). Prolongation of the QTC > 0.46 s was observed in 0.69% of ECGs. CONCLUSIONS: The vast majority of ECGs performed in military aircrew could be classified as representing likely normal physiological changes. Training unrelated ECG changes, suggestive of possible genuine cardiac pathology, were observed in only a minority of persons who should be considered for further investigation.

Monitoring prolongation of QT interval in patients with multidrug-resistant tuberculosis and non-tuberculous mycobacterium using mobile health device AliveCor.

Multidrug resistant tuberculosis and non-tuberculous mycobacterium infections present challenges due to complex treatment regimens. Extended treatment regimes expose patients to higher risks of toxic side-effects. A high drug toxicity profile necessitates closer monitoring. One of the more challenging issues is QTc prolongation with non-injectable regimens. This study investigates the portable AliveCor device to record and measure the QTc on a 6-lead ECG. An automated QTc readout from 12-Lead ECG for each patient (n = 13) and mean QTc value calculated from each patients' respective AliveCor tracing were compared. The general trend suggests AliveCor underestimates QTc - 92% cases calculated the AliveCor QTc as lower than their corresponding 12-Lead QTc readout. The use of AliveCor could potentially be translated into current clinical practice with caution of percentage variation either side. This could facilitate the use of AliveCor as a promising and convenient screening tool before further evaluation by a 12-Lead ECG is required.

MRI measurement of alanine uptake in a mouse xenograft model of U-87 MG glioblastoma.

The potential use of alanine as an MRI contrast agent was investigated. The relaxation properties of alanine solutions were measured at 9.4 T. The T2 relaxivity caused by the chemical exchange (R2ex) between amine protons and water protons was 0.10 mM-1 s-1 at 37 °C. As a demonstration, alanine uptake in a mouse xenograft model of U-87 MG glioblastoma was measured using MRI, and was compared with immunohistochemistry staining of ASCT2, a transporter that imports amino acids into cancer cells. Statistically significant (p = 0.0079) differences in ASCT2 distribution were found between regions that show strong and weak alanine uptake in MRI. To better understand the influence of perfusion, the effect of ASCT2 inhibition on the alanine uptake in MRI was investigated, and dynamic contrast enhanced MRI was compared with alanine MRI.

Interferon-γ release assay screening in biologics: safe and reliable, but not perfect.

Background: Systemic biologic agents can increase the risk of re-activation of latent tuberculosis (TB). Prior to initiation, screening for latent TB using an interferon-γ release assay (IGRA) is recommended. There is concern that false-negative IGRAs may be more likely in this context. Methods: This retrospective analysis of IGRAs, specifically T-SPOT.TB, results and outcomes of patients already on or due to start biologics identifies the rate of TB re-activation in a low TB incidence setting. Additionally, we estimate the negative predictive value (NPV) of IGRAs in this population. Results: Patients on biologics were more likely to have a negative IGRA result than patients not on biologics. There was no statistically significant change in conversion or reversion rates between groups. Of 9263 patients on biologics, 19 developed active TB after starting biologics at an incidence rate of 55.1 per 100 000 patient-years. This occurred despite screening in half of the 16 patients for whom we were able to review medical records. Most drugs implicated were known to be high risk, although rituximab and natalizumab were being taken by five patients and one patient, respectively. The T-SPOT.TB NPV was 99.20% and dropped only slightly to 99.17% when we simulated an approach where all borderline IGRA results were regarded as being negative. Conclusions: Negative IGRA results confer a low risk of subsequent active TB in patients on biologics in a low TB incidence setting. However, continued awareness is needed given that a number of active TB cases will have had a prior negative result.

Ligation-free isothermal nucleic acid amplification.

In this study, we uncover a ligation-free DNA extension method in two adjacent fragmented probes, which are hybridized to target RNA, for developing a ligation-free nucleic acid amplification reaction. In this reaction, DNA elongation occurs from a forward probe to a phosphorothioated-hairpin probe in the presence of target RNA regardless of ligation. The second DNA elongation then occurs simultaneously at the nick site of the phosphorothioated probe and the self-priming region. Therefore, the binding site of the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 12a is repeatedly amplified, inducing a fluorescence signal in the presence of CRISPR-Cas12a. This ligation-free isothermal gene amplification method enables the detection of target RNA with 49.2 fM sensitivity. Moreover, two types of mRNA detection are feasible, thus, demonstrating the potential of this method for cancer companion diagnostics. Notably, the proposed method also demonstrates efficacy when applied for the detection of mRNA extracted from human cells and tumor-bearing mouse tissue and urine samples. Hence, this newly developed ligation-free isothermal nucleic acid amplification system is expected to be widely used in a variety of gene detection platforms.

Structural and thermodynamic investigations on the aggregation and folding of acylphosphatase by molecular dynamics simulations and solvation free energy analysis.

Protein engineering method to study the mutation effects on muscle acylphosphatase (AcP) has been actively applied to describe kinetics and thermodynamics associated with AcP aggregation as well as folding processes. Despite the extensive mutation experiments, the molecular origin and the structural motifs for aggregation and folding kinetics as well as thermodynamics of AcP have not been rationalized at the atomic resolution. To this end, we have investigated the mutation effects on the structures and thermodynamics for the aggregation and folding of AcP by using the combination of fully atomistic, explicit-water molecular dynamics simulations, and three-dimensional reference interaction site model theory. The results indicate that the A30G mutant with the fastest experimental aggregation rate displays considerably decreased α1-helical contents as well as disrupted hydrophobic core compared to the wild-type AcP. Increased solvation free energy as well as hydrophobicity upon A30G mutation is achieved due to the dehydration of hydrophilic side chains in the disrupted α1-helix region of A30G. In contrast, the Y91Q mutant with the slowest aggregation rate shows a non-native H-bonding network spanning the mutation site to hydrophobic core and α1-helix region, which rigidifies the native state protein conformation with the enhanced α1-helicity. Furthermore, Y91Q exhibits decreased solvation free energy and hydrophobicity compared to wild type due to more exposed and solvated hydrophilic side chains in the α1-region. On the other hand, the experimentally observed slower folding rates in both mutants are accompanied by decreased helicity in α2-helix upon mutation. We here provide the atomic-level structures and thermodynamic quantities of AcP mutants and rationalize the structural origin for the changes that occur upon introduction of those mutations along the AcP aggregation and folding processes.