Browsing by Author "Hajela, K"

Now showing 1 - 6 of 6
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    Carbohydrate induced modulation of cell membrane. IV: Interaction with mucin and fucoidan totally immobilizes the human platelet membrane.
    (1996-08-01) Hajela, K; Kayestha, R; Sumati,
    P selectins and E selectins are cell adhesion molecules that mediate the interaction of platelets and endothelial cells with neutrophils and monocytes. The proposed ligands for these receptors contain the Le(x) core, sialic acid and sulfated fucose. In this paper we report that binding of sialic acid markedly restricts the mobility of membrane proteins and lipids as studied by EPR spectroscopy using spin probes. Binding of mucin and fucoidan totally restricts the mobility probably due to cross-linking of the surface lectins. Binding of these ligands also resulted in an increase in the cytoplasmic viscosity.
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    Carbohydrate induced modulation of cell membrane. V : ESR characterization of molecular mobility in lipid bilayer of human neutrophil plasma membrane.
    (1996-06-01) Hajela, K; Kayestha, R; Sumati,
    Physiological changes in neutrophils after binding of sialic acid, mucin and fucoidan have been investigated using spin probes. Binding of sialic acid markedly reduces the mobility of neutrophil membrane proteins and lipids. Binding of mucin and fucoidan totally restricts the mobility probably due to cross linking of the surface lectins. Binding of these ligands also resulted in an increase in the cytoplasmic viscosity.
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    Changes in membrane fluidity induced by binding of immunoglobulins to sperm Fc receptors.
    (1998-03-01) Hajela, K; Sumati,; Kayestha, R; Berry, A
    Receptors for Fc region of immunoglobulins (FcR) are reported to be present on spermatozoa, and also detected in seminal plasma, however their function is still not known. Since various changes in sperm membrane architecture during maturation and passage through female genital tract are reported, experiments were conducted to study the membrane fluidity changes in sperm subsequent to ligation of surface FcR with immunoglobulin and its derivatives. This paper reports that interaction with IgG restricts rotational mobility of cell surface proteins and membrane lipids as studied by EPR spectroscopy using spin probes. Decrease in fluidity was much more pronounced in the presence of aggregated IgG due to crosslinking of sperm FcR by aggregated IgG.
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    Characterization of a lectin from goat peripheral blood lymphocytes.
    (1996-12-01) Kayestha, R; Sumati,; Hajela, K
    A D-glucose specific lectin was isolated from goat peripheral blood lymphocytes by affinity chromatography on N-acetyl D-glucosamine agarose gel. The fluorescence intensity of 4 methyl umbelliferyl D-glucose was quenched to about 62% on addition of the lectin. This lectin gave a single band corresponding to 112 kDa in SDS-PAGE irrespective of treatment with 2-mercaptoethanol. The molecular weight and the Stoke's radius of the lectin in the native conditions were found to be 114 kDa and 4.54 nm, respectively, as determined by gel filtration on Sephacryl S 500 column. The lectin was found to be a glycoprotein with 5.6% of neutral hexose content and 5.5% of sialic acid. The lectin agglutinated trypsinized rabbit erythrocytes and human type A erythrocytes. The hemagglutinating activity was dependent on the presence of divalent cations like Mn2+ and Ca2+. Optimum pH, ionic strength and temperature for rebinding of lectin to acid treated Sephadex G200 were found to be 7.5, 0.16 and 30-37 degrees C, respectively.
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    Comparative and evolutionary analyses of cyclophilins in Cucumis sativus, Phaseolus vulgaris, and Vitis vinifera
    (Open Science Publishers LLP, 2025-02) Yadav, N; Bharill, N; Gautam, Y; Raghuvanshi, R; Meda, S; Hajela, K; Dholakia, B; Tiwari, A; Suravajhala, P; Ratnaparkhe, MB.
    Cyclophilins, ubiquitous proteins present in the majority of organisms including bacteria, fungi, higher plants, humans, and so on, are known to play diverse cellular functions. In this study, we have performed genome-wide analyses of cyclophilins from three plant species, Cucumis sativus, Phaseolus vulgaris, and Vitis vinifera. This analysis revealed 21, 26, and 22 cyclophilins in C. sativus, P. vulgaris, and V. vinifera, respectively. The majority of cyclophilins are present in the cytosol and nucleus, while few were observed in mitochondria and vacuole. A total of 15, 19, and 16 single-domain cyclophilins while 6, 7, and 6 multi domain cyclophilins are present in C. sativus, P. vulgaris, and V. vinifera. Furthermore, phylogenetic analysis showed the grouping of cyclophilins in five major clades with relevance to domains and sub cellular localization. Our study also suggests P. vulgaris and V. vinifera have similar intron exon structures. Eight motifs have been conserved in most cyclophilins out of which six amino acids long motif GSQFFI is prominent. In-silico expression studies revealed CucCYP13 is highly expressed in roots (10 folds higher) and is orthologous to previously reported GmCYP1 of G. max. CucCYP13 from C. sativus has been identified as ortholog of GmCYP1 which plays important role in disease resistance in soybean. Additionally, CucCYP2, PhvCYP22, and GsvCYP5 which have high sequence similarity with Arabidopsis CYP 71 (AT3g44600) could play a key role in gene repression, organogenesis, and meristem development. Overall, the present study offers key insight into this important class of immunophilin, and the newly identified cyclophilins in P. vulgaris, C. sativus, and V. vinifera may play important roles in abiotic stresses and key physiological traits.
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    Recounting COVID-19 associated complement-mediated coagulopathies: Triggers and controls
    (National Academy of Medical Sciences, 2024-10) Lata, P; Madhuri, M; Ali, A; Kumari, B; Tiwari, M; Kumar, A; Hajela, K; Bhushan, D; Sharma, S.
    The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a global health crisis, prompting extensive research into its pathogenesis and potential therapeutic interventions. One area of increasing interest is the interaction between SARS-CoV-2 and the complement system, a crucial component of innate immunity. This review explores the intricate relationship between COVID-19 and the complement system, shedding light on how the virus exploits and manipulates the complement components to induce inflammatory responses leading to coagulopathies. The activation of the complement pathway simultaneously activates the coagulation cascade due to the presence of common substrates of mannan-binding serine proteases of the lectin complement system in the coagulation pathway. This cross-talk between the components of the complement and coagulation system further aggravates the dysregulation of immune responses, contributing to the cytokine storm observed in severe COVID-19 cases. A comprehensive understanding of this crosstalk is crucial for developing targeted therapeutic strategies to mitigate the hyperinflammatory state associated with severe disease. Understandings into the molecular mechanisms governing this interaction may pave the way for the development of novel antiviral diagnostics and therapies based on immunomodulatory interventions, offering better management for such cases.