Sudeshna Ghosh

Indian Institute of Technology Kanpur | IIT Kanpur · Department of Chemistry

Small heat shock proteins (sHSPs) belong to the superfamily of molecular chaperones. They prevent aggregation of partially unfolded or misfolded client proteins, providing protection to organisms under stress conditions. Here, we report the biophysical and structural characterization of a small heat shock protein (HspA) from a thermophilic cyanobac...

The cascade of amyloid formation relates to multiple complex events at the molecular level. Previous research has established amyloid plaque deposition as the leading cause of Alzheimer's disease (AD) pathogenesis, detected mainly in aged population. The primary components of the plaques are two alloforms of amyloid-beta (Aβ), Aβ1-42 and Aβ1-40 pep...

Self-assembly of disordered amyloid-beta (Aβ) peptides results in highly ordered amyloid fibrils. The structural information of the early-stage events and also in the presence of inhibitors is of great significance. It is challenging to acquire due to the nature of the amyloids and experimental constraints. Here, we demonstrate the cascade of aggre...

Several DNA binding proteins exist in dimeric form when bound with DNA to be able to exhibit various biological processes such as DNA repair, DNA replication and gene expression. Various dimeric forms of Ribonuclease A (RNase A) and other members of the ribonuclease A superfamily are endowed with a multitude of biological activities such as antitum...

Protein self-association leads to toxic filamentous plaques believed to be the key reason behind several neurodegenerative diseases. Stabilization of the fibrillar architecture is guided by several forces; primarily electrostatic, hydrophobic, and the extent of hydrogen bonding. In this study, we experimentally demonstrate, for the first time, the...

Abstract Hen egg white lysozyme (HEWL) adopts a molten globule like state at high pH (~12.75) and is found to form amyloid fibrils at alkaline pH. Here, we report that Cu(II) inhibits self-association of hen egg white lysozyme (HEWL) at pH 12.75 both at 37 °C and 65 °C. A significant reduction in Thioflavin T (ThT) fluorescence intensity, attenuati...

The in vivo deposition of toxic proteinaceous aggregates with fibrillar morphology has been known to direct the pathogenesis of severe neurological disorders. The stability of proteins under the crowded cellular milieu might be crucial for the fate of proteins in terms of aggregation. Here in the present report, we have examined the effect of ethan...

Lactoferrin (LF) has several biological effects ranging from ribonuclease activity to antiangiogenic activity. It thus serves as a potential target protein for studies related to ribonucleolytic activity in association with its antiangiogenic activity. We have isolated buffalo LF and checked the ribonucleolytic activity via an agarose gel-based ass...

Knowing the distribution of Ramachandran angles helps in understanding peptide and protein backbone conformation. Empirical relations are proposed to correlate the spectral profile of the amide III3 band, obtained from ultra-violet resonance Raman measurements (UVRR), with the Ramachandran dihedral psi angle distribution in small peptide and protei...

Glycation causes severe damage to protein structure that could lead to amyloid formation in special cases. Here in this report, we have shown for the first time that hen egg white lysozyme (HEWL) does not undergo amyloid formation even after prolonged glycation in the presence of D-glucose, D-fructose and D-ribose. Cross-linked oligomers were forme...

Protein aggregation is related to a series of pathological disorders the main cause of which are the fibrillar species generated during the process. Human serum albumin (HSA) undergoes rapid fibrillation in the presence of Cu(II) at pH 7.4 in 60% ethanol after 6-h incubation (∼65 °C) followed by room temperature incubation. Here, we have investigat...

The difference in molecular structure of native HEWL and its fibrils, grown at a pH value near physiological pH 7.4 and at a pH value just above the pI, 10.7 in presence and absence of Cu(II) ions, is discussed. We focus on differences between the molecular structure of the native protein and fibrils using principal component analysis of their Rama...

Green tea polyphenols (GTPs) are found to be potent inhibitors of amyloid fibril formation. We report the effective inhibitory property of (-)-epicatechin gallate (ECG) during the alkali-salt induced fibrillogenesis of Hen egg white lysozyme (HEWL) at 37°C. Spectroscopic techniques such as fluorescence, circular dichroism and microscopic images sho...

Copper is known to exert diverse effects on the self-association of proteins and has been found in amyloid deposits that are involved in neurodegenerative disease processes. The effects of the metal ion on the protein during fibrillation were investigated by fluorescence, circular dichroism spectroscopy and fluorescence microscopy. We report for th...

The aggregation process in proteins is governed by several factors such as temperature, pH, presence of electrolytes, denaturants, and metal ions. Here, we report the role of Cu(II) in inducing rapid fibrillation in human serum albumin. We have monitored this process via UV-vis spectroscopy, fluorescence spectroscopy, circular dichroism, zeta-poten...