2024- (IISER Pune)- Investigating the aggregation pathways of amyloidogenic light chains (LCs) associated with AL amyloidosis: In this research, we aim to understand how the structural and biophysical features of a native LC change as it progresses to the mature fibril stage. We study this process using multiple biophysical and structural biology methods, using full-length LCs and their isolated variable domain as models. The pictorial presentation of the overview is shown in the figure on the right.
- Investigating the impact of pathogenic mutations on the aggregation behavior of amyloidogenic LCs associated with AL amyloidosis: The variable domain of LCs contains several mutations that contribute to their amyloidogenic behavior and soluble toxicity. However, it is not well explored how these pathogenic mutations influence the aggregation behavior of LCs. In this project, we aim to investigate how different mutations affect the aggregation behavior and soluble toxicity of amyloidogenic LCs using biochemical, biophysical, and structural biology methods and cell-based toxicity assays.
- Investigating the impact of oxidative stress on the aggregation behavior of amyloidogenic LCs: Soluble toxicity exerted by the native LCs and their soluble oligomers results in the over-production of reactive oxygen species (ROS), mitochondrial dysfunctioning, and production of different biomarkers like proBNP in the heart. However, it is not established in the literature whether ROS production modulates the aggregation behavior of pathogenic LCs. To understand this, we will also study the impact of oxidative stress on the aggregation pathways of LCs.
2022-2024 (Department of Bioscience, University of Milan, Italy)- Cryo electro-microscopy-based structural studies on light chain amyloid fibrils extracted from different organs of AL amyloidosis patients: In this work, we demonstrated for the first time that the microenvironment of different organs does not affect the amyloid structural organization. This finding is important for designing generalized anti-amyloid compounds for AL patients.
- Investigating the molecular determinants of aggregation and soluble toxicity in native LCs associated with AL amyloidosis: In this project, we use pathogenic native LCs from patients as a model to understand their structural and biophysical features which contribute to their higher aggregation propensity and soluble toxicity. We and many other groups found that reduced stability, higher dynamics, and altered dimeric interfaces contribute to their pathogenic behavior.
2019-2022 (IBC, Academia Sinica, Taiwan)- Understanding the impact of oxidative modifications and pathological mutations on the structure-activity relationship of deubiquitinase enzymes UCH-L1 and BAP1: In this work, we established that surface-exposed C152 acts as a reactive oxygen scavenger in UCH-L1. At the same time, the oxidation of catalytic cysteine leads to function loss and soluble aggregation.
- Investigating the folding pathways of knotted proteins: Using MJ0366, a trefoil knotted smallest known protein, we established the role of non-native interactions at the early stages of folding to guide the knotting and folding of this protein. I also worked on investigating the folding pathway of the circularly permutant form (CP74) of a knotted protein YbeA.
2013-2018 (School of Biological Sciences, IIT Delhi, India)- Investigating the folding pathway of a multidomain protein GroEL monomer: In this work, we established the sequential folding pathway with an intermediate state consisting of folded apical and unfolded intermediate and equatorial domains.
- Role of intra and inter-subunit interactions in stability and assembly of chaperonin GroEL: In this project, we found that both inter- and intra-subunit interactions are crucial for the folding and assembly of GroEL chaperonin. In contrast, inter-subunit charge interactions mainly contribute to oligomerization.
- Improvement of structural stability and functional efficiency of chaperonin GroEL for its industrial use: Through this work, we have been successful in optimizing conditions to enhance the thermodynamic stability and functioning of GroEL protein to increase its use for the folding of many different substrate proteins under harsh experimental conditions.
