Experimental methods to study the structure and dynamics of intrinsically disordered regions in proteins.

Eukaryotic proteins often feature long stretches of amino acids that lack a well-defined three-dimensional structure and are referred to as intrinsically disordered proteins (IDPs) or regions (IDRs). Although these proteins challenge conventional structure-function paradigms, they play vital roles in cellular processes. Recent progress in experimental techniques, such as NMR spectroscopy, single molecule FRET, high speed AFM and SAXS, have provided valuable insights into the biophysical basis of IDP function. This review discusses the advancements made in these techniques particularly for the study of disordered regions in proteins. In NMR spectroscopy new strategies such as 13C detection, non-uniform sampling, segmental isotope labeling, and rapid data acquisition methods address the challenges posed by spectral overcrowding and low stability of IDPs. The importance of various NMR parameters, including chemical shifts, hydrogen exchange rates, and relaxation measurements, to reveal transient secondary structures within IDRs and IDPs are presented. Given the high flexibility of IDPs, the review outlines NMR methods for assessing their dynamics at both fast (ps-ns) and slow (µs-ms) timescales. IDPs exert their functions through interactions with other molecules such as proteins, DNA, or RNA. NMR-based titration experiments yield insights into the thermodynamics and kinetics of these interactions. Detailed study of IDPs requires multiple experimental techniques, and thus, several methods are described for studying disordered proteins, highlighting their respective advantages and limitations. The potential for integrating these complementary techniques, each offering unique perspectives, is explored to achieve a comprehensive understanding of IDPs.

Stability and dynamics of extradenticle modulates its function.

Extradenticle (EXD) is a partner protein of the HOX transcription factors and plays an important role in the development of Drosophila. It confers increased affinity and specificity of DNA-binding to the HOX proteins. However, the DNA-binding homeodomain of EXD has a significantly weaker affinity to DNA compared to the HOX homeodomains. Here, we show that a glycine residue (G290) in the middle of the EXD DNA-binding helix primarily results in this weaker binding. Glycine destabilizes helices. To probe its role in the stability and function of the protein, G290 was mutated to alanine. The intrinsic stability of the DNA-binding helix increased in the G290A mutant as observed by NMR studies and molecular dynamics (MD) simulation. Also, NMR dynamics and MD simulation show that dynamic motions present in the wild-type protein are quenched in the mutant. This in turn resulted in increased stability of the entire homeodomain (ΔΔGG→A of -2.6 kcal/mol). Increased protein stability resulted in three-fold better DNA-binding affinity of the mutant as compared to the wild-type protein. Molecular mechanics with generalized Born and surface area solvation (MMGBSA) analysis of our MD simulation on DNA-bound models of both wild-type and mutant proteins shows that the contribution to binding is enhanced for most of the interface residues in the mutant compared to the wild-type. Interestingly, the flexible N-terminal arm makes more stable contact with the DNA minor groove in the mutant. We found that the two interaction sites i.e. the DNA-binding helix and the unstructured N-terminal arm influence each other via the bound DNA. These results provide an interesting conundrum: alanine at position 290 enhances both the stability and the DNA-binding affinity of the protein, however, evolution prefers glycine at this position. We have provided several plausible explanations for this apparent conundrum. The function of the EXD as a HOX co-factor requires its ability to discriminate similar DNA sequences, which is most likely comprom.

Social media use among adolescents with eating disorders: a double-edged sword.

Eating disorders are on the rise with a significant impact on mental health. Misuse of social media platforms is likely a significant contributing factor. This trend is especially pronounced among adolescents, who are increasingly using social media platforms for communications, building relationships, learning and entertainment. The unsupervised sharing of social media content can have drastic consequences on the physical and psychological wellbeing of youth, which often takes the form of "thinspiration" or "fitspiration". This probably serves as a trigger for those already struggling with eating disorders. In addition, there is a lack of awareness among youth and adults on ideal knowledge-sharing practices related to an eating disorder. By addressing the unique challenges that social media presents for youth with eating disorders, communities can work towards creating a safer and more supportive online environment on a global scale. At this junction, this article aims to share the current challenges of social media use among adolescents with eating disorders and put forth recommendations for how social media could be used as a tool for positive impact in this population.

A tertiary care centre experience with Elranatamab: A report of three cases.

Introduction: The introduction of proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies has changed the treatment paradigm of multiple myeloma. With the advent of these new therapeutic options, life expectancy has substantially increased for myeloma patients which has led to an increased number of patients with triple-class refractory disease. Thus, there remains an unmet need for effective novel therapies with good tolerability and safety profile. Elranatamab, is the most widely used bispecific antibody currently in the Indian setting. However, it has only been used on a clinical trial basis till now, and real-world data especially in the Indian setting is missing. Here, we present our experience with three cases of multi-line treated relapsed/refractory multiple myeloma on elranatamab monotherapy. Case report: We here discuss three of our patients with triple class refractory multiple myeloma who recieved elranatamab monotherapy. While one of our patient had been switched to fortnightly treatment, two patients were still continuing weekly treatment. The common adverse effects observed were grade 1-2 cytokine release syndrome, cytopenias, CMV reactivation and hypo-gammaglobulinemia. While two of our patients are doing well, one patient had grade 3 neurological toxicity, likely drug related and succumbed. Discussion: B-cell maturation antigen is highly expressed on mature B cells and is critical for the survival and proliferation of plasma cells. It has emerged as a novel target for anti-myeloma therapies in the form of bispecific cell engager, antibody-drug conjugates, and chimeric antigen receptor (CAR) T-cell therapies.The phase II MM3 trial showed a promising efficacy with an ORR of 61% with a CR rate of >35%. With a median follow-up of 14.7 months, the median PFS was not reached and the 15-month PFS rate was 50.9%. While it is too early to comment on long term survival with the monotherapy, we here discuss response of Indian patients in the real world setting. Conclusion: Elranatamab monotherapy could prove to be an efficacious option for the treatment of relapsed /refractory multiple myeloma patients with triple-class refractory disease, with limited therapeutic options. However, patients need to be screened for infectious complications with appropriate prophylaxis and immunoglobulin replacement, if required. Also, a high suspicion is required for the neurological complications of the drug and a longitudinal neuro-cognitive screening is required for the patients.

Real world outcome of B ALL with t (1; 19) (q23; p13)/TCF3::PBX1 in adolescents and adults treated with intensive regimes.

Significant heterogeneity has been reported in outcome of Acute lymphoblastic leukemia with t(1;19)(q23;p13)/TCF3::PBX1 in adolescents and adults leading to a lack of consensus on precise risk stratification. We evaluated clinical outcome of 17 adult ALL cases (≥15 years) with this genotype treated on intensive regimes.13/17 received COG0232 and 4/17 cases received UK-ALL protocol. All achieved CR (100%) with above treatment. End of induction MRD was evaluated in 14/17 cases of which 11 (78.5%) achieved MRD negativity. Total nine patients relapsed (7 marrows, 2 CNS). Overall survival at 2 years was 53.3%. The 2 year estimated PFS was 42.9%. The 2 years CIR was 54.2%. Adults with this genotype perform poorly despite early favorable response. Incorporation of novel immunotherapies and prompt HSCT should be strongly considered with this genotype. Targeted NGS panels for additional genetic aberrations can further help in risk stratifying and guiding therapy for this genotype.