Biology subjects

Chand, S.

Publications and source records attributed to Chand, S..

5 recordsLinked to original sources

bioRxiv2025

The Current Landscape of Plasma Proteomics: Technical Advances, Biological Insights, and Biomarker Discovery

Plasma is a rich source of biomolecules, including proteins, that reflect both health and disease. Due to their key roles in biological processes, proteins hold significant potential as biomarkers, fueling the rise of plasma proteome profiling in recent years. Despite widespread adoption, few studies have directly compared different plasma proteomics platforms, particularly those using mass spectrometry. Our study provides a comprehensive comparison of seven platforms across three leading technologies - SomaLogic, Olink, and Mass Spectrometry (MS) - including affinity-based approaches and various MS techniques, covering over 13,000 proteins. By applying these methods to the same cohort, we assess their performance, revealing key differences and complementary strengths. Our findings offer valuable insights for researchers, highlighting trade-offs in coverage and their implications for biomarker discovery and clinical applications. This study serves as an essential resource, offering both technical evaluation and biological insights to support the development of novel diagnostics and therapeutics through plasma proteomics.

bioinformatics↗

bioRxiv2023

Assessment of structural behaviour of new L-asparaginase and SAXS data-based evidence for catalytic activity in its monomeric form

The present study reports the structural and functional characterization of a new glutaminase-free recombinant L-asparaginase (PrASNase) from Pseudomonas resinovorans IGS-131. PrASNase showed substrate specificity to L-asparagine, and its kinetic parameters, Km, Vmax, and kcat were 9.49x10-3 M, 25.13 IUmL-1min-1, and 3.01x103 s-1, respectively. The CD spectra showed that PrASNase consists of 30.9% -helix and 69.1% other structures in its native form. FTIR was used for the functional characterization, and molecular docking predicted that the substrate interacts with serine, alanine, and glutamine in the binding pocket of PrASNase. Different from known asparaginases, structural characterization by small-angle X-ray scattering (SAXS) and analytical ultracentrifugation (AUC) unambiguously revealed PrASNase to exist as a monomer in solution at low temperatures and oligomerized to a higher state with temperature rise. Through SAXS studies and enzyme assay, PrASNase was found to be mostly monomer and catalytically active at 37{degrees}C. Furthermore, this glutaminase-free PrASNase showed killing effects against WIL2-S and TF-1.28 cells with IC50 of 7.4 {micro}g.mL-1 and 5.6 {micro}g.mL-1, respectively. This is probably the first report with significant findings of fully active L-asparaginase in monomeric form using SAXS and AUC and demonstrates the potential of PrASNase in inhibiting cancerous cells, making it a potential therapeutic candidate. HIGHLIGHTSO_LIA new L-asparaginase (PrASNase) was structurally and functionally characterized. C_LIO_LISAXS revealed PrASNase is functionally active in monomeric form and oligomerizes with temperature rise. C_LIO_LIMonomeric PrASNase showed an IC50 value of 7.4 and 5.6 {micro}g mL-1 against WIL2-S and TF-1.28 cells. C_LIO_LICytotoxicity of PrASNase against leukemic cell lines showed its potential as a biotherapeutic. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/522448v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@ece494org.highwire.dtl.DTLVardef@92cdbeorg.highwire.dtl.DTLVardef@19a2borg.highwire.dtl.DTLVardef@1308c70_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2021

A genetic shift in an escaped transmitted/founder virus guides combinatorial vaccine design against HIV-1

A productive HIV-1 infection in humans is often established by transmission and propagation of a single transmitted/founder (T/F) virus, which then evolves into a complex mixture of variants during the lifetime of infection. An effective HIV-1 vaccine should elicit broad immune responses in order to block the entry of diverse T/F viruses. Currently, no such vaccine exists. An in-depth study of escape variants emerging under host immune pressure during very early stages of infection might provide insights into such a HIV-1 vaccine design. Here, in a rare longitudinal study involving HIV-1 infected individuals just days after infection in the absence of antiretroviral therapy, we discovered a remarkable genetic shift that resulted in near complete disappearance of the original T/F virus and appearance of a variant with H173Y mutation in the variable V2 domain of the HIV-1 envelope protein. This coincided with the disappearance of the first wave of strictly H173-specific antibodies and emergence of a second wave of Y173-specific antibodies with increased breadth. Structural analyses indicated conformational dynamism of the envelope protein which likely allowed selection of escape variants with a conformational switch in the V2 domain from an -helix (H173) to a {beta}-strand (Y173) and induction of broadly reactive antibody responses. This differential breadth due to a single mutational change was also recapitulated in a mouse model. Rationally designed combinatorial libraries containing 54 conformational variants of V2 domain around position 173 further demonstrated increased breadth of antibody responses elicited to diverse HIV-1 envelope proteins. These results offer new insights into designing broadly effective HIV-1 vaccines.

microbiology↗

bioRxiv2020

Role of selective Bioactive Compounds as an Angiotensin Converting Enzyme Inhibitor

Hypertension is one of a major reason of mortality and morbidity and it is associated with heart and renal disease. The aim of this study is to find out the antihypertensive role of bioactive compounds from selected medicinal plants targeting ACE molecule which so far is not known. The plants taken in this study were Moringa oleifera, Azadirachta indica, and Hibiscus sabdariffa. The nitric oxide and superoxide scavenging property vary from 39.50% to 68% and 37.67 % to 75.50 %. respectively. The inhibition of ACE activity was found maximally in methanolic extract of A. indica (74 %), followed by H. sabdariffa (73.4%), and least in M. oleifera (71.8 %). The bioactive chloroform fraction was characterized for the presence of compound using standard techniques such as LCMS and NMR (13C-NMR 1H-NMR). The results revealed the presence of beta-sitosterol in M. oleifera, azadiradionolide in A. indica and hibiscitrin in H. sabdariffa. The compounds have shown significant low binding energy for hibiscitrin (-12.3kcal/mol), beta-sitosterol (-11.2kcal/mol) and azadiradionolide (-11.3kcal/mol) indicating the high efficacy of binding on the enzyme. While, binding energy of drug captopril was -5.6kcal/mol & enalpril - 8.1kcal/mol in the same pocket of the ACE molecule. Upon subjecting molecular dynamic simulation results indicated that beta sitosterol complex provided more compactness than the hibiscitrin and azadiradionolide compounds. The current study delivers a new perspective for the drug development against systolic blood pressure regulation and also opens new horizons for considering alternate highly potent drug target for hypertension.

bioinformatics↗

bioRxiv2018

C. elegans granulins promote an age-associated decline in protein homeostasis via lysosomal protease inhibition

The progressive failure of protein homeostasis is a hallmark of aging and a common feature in neurodegenerative disease. As the enzymes executing the final stages of autophagy, lysosomal proteases (or cathepsins) are key contributors to maintenance of protein homeostasis with age. Here, we identify the cysteine-rich granulin peptides as a new class of regulators of lysosomal aspartyl protease activity. Granulins are produced in an age and stress-dependent manner through cleavage of the neurodegenerative disease protein, progranulin. Once liberated, granulins selectively interact with the aspartyl protease ASP-3/cathepsin D to impair enzymatic activity. Consequently, protein homeostasis and lysosome function is disrupted, prompting cells to activate a compensatory transcriptional program. Our results support a model in which granulin production modulates a critical transition between the normal, physiological regulation of protease activity and the impairment of lysosomal function that can occur with age and disease.

neuroscience↗