L-asparaginase is a remarkable antineoplastic enzyme used in medicine for the treatment of acute lymphoblastic leukemia (ALL) as well as in food industries. In this work, the L-asparaginase-II gene from Salmonella paratyphi was codon-optimized, cloned, and expressed in E. coli as a His-tag fusion protein.
View Article and Find Full Text PDFGlycation is the non-enzymatic adduct formation between reducing sugars or dicarbonyls with proteins and is a crucial molecular event under hyperglycaemic conditions of diabetes. The accumulation of advanced glycation end products (AGEs) due to glycation of proteins has been implicated in several diseases associated with ageing and diabetes. Thus, investigating the antiglycation potential of some trace metal ions (Manganese; Mn, and Zinc; Zn) and polyphenolic extract of chickpea seeds (PEC) on the methylglyoxal (MGO) induced glycation of a phytocystatin isolated from chickpea was taken up to find an inexpensive and non-toxic therapeutic means of medicating protein glycation and associated diabetic complications.
View Article and Find Full Text PDFTechnol Cancer Res Treat
December 2023
Hepatocellular carcinoma (HCC) is the primary form of liver cancer. It causes ∼ 800 000 deaths per year, which is expected to increase due to increasing rates of obesity and metabolic dysfunction associated steatotic liver disease (MASLD). Current therapies include immune checkpoint inhibitors, tyrosine kinase inhibitors, and monoclonal antibodies, but these therapies are not satisfactorily effective and often come with multiple side effects and recurrences.
View Article and Find Full Text PDFHexokinases (HKs) convert hexose sugars to hexose-6-phosphate, thus trapping them inside cells to meet the synthetic and energetic demands. HKs participate in various standard and altered physiological processes, including cancer, primarily through the reprogramming of cellular metabolism. Four canonical HKs have been identified with different expression patterns across tissues.
View Article and Find Full Text PDFThe continuous loss of human life due to the paucity of effective drugs against different forms of cancer demands a better/noble therapeutic approach. One possible way could be the use of nanostructures-based treatment methods. In the current piece of work, we have synthesized silver nanoparticles (AgNPs) using plant ( extract using AgNO3 as starting materials.
View Article and Find Full Text PDFMethylglyoxal (MG) is a potent glycating agent which reacts with proteins to form advanced glycation end products (AGEs). These chemically stable AGEs crosslink with proteins and could lead to amyloid formation that has the role in several diseases including Alzheimer's and Parkinson's. In this piece of work, glycation-induced conformational changes in HSA were observed with quenching of tryptophan fluorescence by 73.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
May 2019
Protein aggregation leads to vast conformational changes and plays a key role in the pathogenesis of various neurodegenerative diseases including Alzheimer's and Parkinson's. In the current piece of work, we have explored the interaction of quinoline yellow (QY) with myoglobin (Mb) at two different pH (3.5 and 7.
View Article and Find Full Text PDFAmyloid fibrils are highly ordered protein assemblies known to contribute to the pathology of a variety of genetic and aging-associated diseases. Here, we have investigated the aggregation propensity of lysozyme in the presence of a negatively charged surfactant (SDS) and evaluated the anti-aggregation activity of rutin. Multiple approaches such as turbidity measurements, dye binding assays, intrinsic fluorescence, circular dichroism (CD), transmission electron microscopy (TEM), MTT and comet assays have been used for this purpose.
View Article and Find Full Text PDFBiochim Biophys Acta Proteins Proteom
September 2018
Hyperglycaemic conditions facilitate the glycation of serum proteins which may have predisposition to aggregation and thus lead to complications. The current study investigates the glycation induced structural and functional modifications of chickpea cystatin (CPC) as well as biological toxicity of the modified protein forms, using CPC-glucose as a model system. Several structural intermediates were formed during the incubation of CPC with glucose (day 4, 8, 12, & 16) as revealed by circular dichroism (CD), altered intrinsic fluorescence, and high ANS binding.
View Article and Find Full Text PDFReactive dicarbonyl species such as methylglyoxal (MGO) and glyoxal (GO) have recently received extensive attention due to their high reactivity and ability to modify biological substances such as proteins, phospholipids, and DNA. In case of proteins these reactive species mainly react with lysine and arginine residues to form AGEs, oxidative products, and aggregates. Chickpea cystatin (CPC) was incubated with varying concentrations of glyoxal and methylglyoxal which caused, along with altered secondary and tertiary structures, glycation, functional inactivation, altered redox state, cross-linking and high-molecular-mass aggregation.
View Article and Find Full Text PDFSeveral mammalian proteins form pathological deposits under nonphysiological conditions that are associated with many degenerative diseases. Protein aggregation is associated with aging, as well as a variety of diseases, including cystic fibrosis, amyotrophic lateral sclerosis (ALS), and hypertrophic cardiomyopathy. There is a lack of any potential anti-amyloidogenic agents and therapeutics till date.
View Article and Find Full Text PDFThe maintenance of health requires successful cell functioning, which in turn depends upon the proper and active conformation of proteins besides other biomolecules. However, occasionally these proteins may misfold and lead to the appearance and progression of protein conformational diseases. These diseases apart from others include several neurodegenerative disorders (NDDs) such as Alzheimer's disease, Parkinson disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, and other lesser known diseases.
View Article and Find Full Text PDFZnO-NPs have been widely used in biomedical fields such as therapeutics, cellular imaging, and drug delivery. However, the risk of exposure of nanoparticles to the biological system is not well understood. Nanoparticle-protein interaction is pivotal to understand their biological behavior and predict nanoparticle toxicity that is crucial for its safer applications.
View Article and Find Full Text PDFMany protein misfolding diseases in mammalian system are characterised by the accumulation of protein aggregates in amyloid fibrillar forms. Several therapeutic approaches include reduction in the production of the amyloidogenic form of proteins, increase in the clearance rate of misfolded or aggregated proteins, and direct inhibition of the self-assembly process have been explained. One of the possible remedial treatments for such disorders may be to identify molecules which are capable of either preventing formation of fibrils or disintegrating the formed fibrils.
View Article and Find Full Text PDFThe binding study of pesticides with proteins is of great importance in ecotoxicology. In this study, a comparative interaction mechanism of phytocystatin with three pesticides has been presented, each from a different class-glyphosate herbicide (GPS), chlorpyrifos insecticide (CPF), and mancozeb fungicide (MCZ). The interaction of purified chickpea cystatin (CPC) has been characterized by fluorescence, UV, and circular dichroism (CD) spectroscopic methods.
View Article and Find Full Text PDFα-Crystallin is a member of small heat shock proteins and is believed to play an exceptional role in the stability of eye lens proteins. The disruption or denaturation of the protein arrangement or solubility of the crystallin proteins can lead to vision problems including cataract. In the present study, we have examined the effect of chemical denaturants urea and guanidine hydrochloride (GdnHCl) on α-crystallin aggregation, with special emphasis on protein conformational changes, unfolding, and amyloid fibril formation.
View Article and Find Full Text PDFFib having intrinsically disordered αC domains is involved in coagulation cascade and thrombosis. Fib molecules forms prefibrillar oligomers at 30%, and associate in 40 and 50% TFE to proceed α to β transition, suggesting the formation of an intermolecular β-structure. AFM images confirmed the nature of Fib aggregates at 40 and 50% TFE to be prefibrillar and fibrillar respectively.
View Article and Find Full Text PDFSeveral mammalian proteins fold abnormally under non physiological conditions, to form pathological deposits that are associated with many degenerative diseases. In vitro variation of solvent conditions and pH can lead to partial unfolding and subsequent fibril formation. In the present study, we examined the effects of low pH on goat brain cystatin (GBC) with a focus on amyloid fibril formation.
View Article and Find Full Text PDFThiol protease inhibitors (cystatins) are implicated in various disease states from cancer to neurodegenerative conditions and immune responses. Cystatins have high amyloidogenic propensity and they are prone to form fibrillar aggregates leading to amyloidosis. Particularly challenging examples of such disorders occur in type 2 diabetes, Alzheimer's and Parkinson's diseases.
View Article and Find Full Text PDFConformational alterations and aggregates of chickpea cystatin (CPC) were investigated upon sequential addition of trifluoroethanol (TFE) over a range of 0-70% v/v. CPC on 30% and 40% v/v TFE addition exhibited non-native β-sheet, altered intrinsic fluorescence, increased thioflavin T fluorescence, prominent red shifted shoulder peak in Congo red absorbance, and enhanced turbidity as well as Rayleigh scattering, suggesting the aggregate formation. TEM results confirmed the formation of fibrillar aggregates at 30% and 40% v/v TFE.
View Article and Find Full Text PDFThe study shows the effect of nonenzymatic glycation on conformation and inhibitory activity of chick pea cystatin (CPC). CPC was incubated with different reducing sugars, pentose (D-Ribose), hexoses (D-Glucose, D-Fructose) at 37 °C for 5 weeks. To evaluate the modification of CPC by these different sugars during the glycation process the extent of the Maillard reaction, conformational, structural and functional changes were investigated.
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