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101.
Modulation of sialic acid-binding proteins of rat uterus in response to changing hormonal milieu 总被引:1,自引:0,他引:1
Indrani Chakraborty Chhabinath Mandal Mridula Chowdhury 《Molecular and cellular biochemistry》1993,126(1):77-86
A group of sialic acid binding (SAS) agglutinins has been isolated from the rat uteri at different stages [Proestrus (P), estrus (E) and diestrus (D)] of estrous cycle. Studies of biochemical properties indicate that SAS agglutinins are glycoprotein in nature having molecular weights between 28–31 Kd and microheterogenous pI. Function-based characterization revealed that inspite of the fact that all three proteins exhibit sialic acid binding property, the sialic acid binding affinities, calculated from Scatchard analysis, using 4-methylumbelliferyl sialic acid as a ligand, varied in stage specific manner (Ka:D-SAS-9.03×105 M–1, P-SAS-2.33×105 M–1, E-SAS-2.13×105 M–1). Circular dichroism spectra of these three agglutinins suggested that differences exist in the secondary structures of the proteins isolated from different stages. Removal of carbohydrate moiety by trifluoromethane sulfonic acid treatment and CNBr cleavage studies showed some homology between these proteins, however, the variation in the carbohydrate moiety was apparent from the sugar analysis data. Functionally and immunologically these proteins can be grouped as estrogenic and progestogenic SAS agglutinins. 相似文献
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103.
Ram Krishna Thakur Vinod Kumar Yadav Akinchan Kumar Ankita Singh Krishnendu Pal Luke Hoeppner Dhurjhoti Saha Gunjan Purohit Richa Basundra Anirban Kar Rashi Halder Pankaj Kumar Aradhita Baral MJ Mahesh Kumar Alfonso Baldi Bruno Vincenzi Laura Lorenzon Rajkumar Banerjee Praveen Kumar Viji Shridhar Debabrata Mukhopadhyay Shantanu Chowdhury 《Nucleic acids research》2014,42(18):11589-11600
104.
M. A. Malek N. A. Chowdhury Q. M. Youssouf N. Choudhury 《Enzyme and microbial technology》1988,10(12):750-753
Five locally isolated bacterial strains produced extracellular cellulase enzymes, primarily CMCase, when grown on different natural and commercial cellulosic substrates. Extracellular CMCase and avicelase activity was higher with the strain CLS-32, a Cytophaga sp., compared to four other strains. The whole-cell preparations of these isolates were found to saccharify cellulosic substrates to reducing sugars. Maximum release of reducing sugar (5.75 mg ml−1) was obtained with CLS-32 using sugar cane bagasse as growth and hydrolysis substrates. 相似文献
105.
Margherita Rosati Mahesh Agarwal Xintao Hu Santhi Devasundaram Dimitris Stellas Bhabadeb Chowdhury Jenifer Bear Robert Burns Duncan Donohue Laurent Pessaint Hanne Andersen Mark G. Lewis Evangelos Terpos Meletios Athanasios Dimopoulos Alexander Wlodawer James I. Mullins David J. Venzon George N. Pavlakis Barbara K. Felber 《PLoS pathogens》2021,17(9)
The speed of development, versatility and efficacy of mRNA-based vaccines have been amply demonstrated in the case of SARS-CoV-2. DNA vaccines represent an important alternative since they induce both humoral and cellular immune responses in animal models and in human trials. We tested the immunogenicity and protective efficacy of DNA-based vaccine regimens expressing different prefusion-stabilized Wuhan-Hu-1 SARS-CoV-2 Spike antigens upon intramuscular injection followed by electroporation in rhesus macaques. Different Spike DNA vaccine regimens induced antibodies that potently neutralized SARS-CoV-2 in vitro and elicited robust T cell responses. The antibodies recognized and potently neutralized a panel of different Spike variants including Alpha, Delta, Epsilon, Eta and A.23.1, but to a lesser extent Beta and Gamma. The DNA-only vaccine regimens were compared to a regimen that included co-immunization of Spike DNA and protein in the same anatomical site, the latter of which showed significant higher antibody responses. All vaccine regimens led to control of SARS-CoV-2 intranasal/intratracheal challenge and absence of virus dissemination to the lower respiratory tract. Vaccine-induced binding and neutralizing antibody titers and antibody-dependent cellular phagocytosis inversely correlated with transient virus levels in the nasal mucosa. Importantly, the Spike DNA+Protein co-immunization regimen induced the highest binding and neutralizing antibodies and showed the strongest control against SARS-CoV-2 challenge in rhesus macaques. 相似文献
106.
Ramachandran Saraswathi Rakhi Pait Chowdhury Sunanda Margrett Williams Payel Ghatak Dipankar Chatterji 《PloS one》2009,4(11)
The Dps (DNA-binding protein from starved cells) proteins from Mycobacterium smegmatis MsDps1 and MsDps2 are both DNA-binding proteins with some differences. While MsDps1 has two oligomeric states, with one of them responsible for DNA binding, MsDps2 has only one DNA-binding oligomeric state. Both the proteins however, show iron-binding activity. The MsDps1 protein has been shown previously to be induced under conditions of starvation and osmotic stress and is regulated by the extra cellular sigma factors σH and σF. We show here, that the second Dps homologue in M. smegmatis, namely MsDps2, is purified in a DNA-bound form and exhibits nucleoid-like structures under the atomic force microscope. It appears that the N-terminal sequence of Dps2 plays a role in nucleoid formation. MsDps2, unlike MsDps1, does not show elevated expression in nutritionally starved or stationary phase conditions; rather its promoter is recognized by RNA polymerase containing σA or σB, under in vitro conditions. We propose that due to the nucleoid-condensing ability, the expression of MsDps2 is tightly regulated inside the cells. 相似文献
107.
Shakhawat Chowdhury 《人类与生态风险评估》2012,18(5):1051-1068
Dermal exposure to volatile compounds (VC) in municipal water while showering is typically estimated using a steady-state condition between VC in water impacting on skin and skin exposed to water. The lag times to achieve steady-state between VC and skin can vary in the range of 7.5–218.3 min, while shower duration is often less than these values. Estimates of dermal exposure to VC using steady-state while showering may misinterpret exposure. This study developed models and estimated exposure to some disinfection byproducts (DBPs) through dermal pathway by considering lag times while showering. Dermal uptakes of VC were compared using different approaches. In the proposed approach, uptakes of trihalomethanes were estimated between 9.55 × 10?10–1.43 × 10?8 mg/cm2 of skin during the lag times from exposure to water with trihalomethanes of 50 μg/L. These values were higher than the steady-state estimates (1.37 × 10?10–4.34 × 10?9 mg/cm2), and lower than the average exposure analysis (4.12 × 10-8–1.93 × 10?6 mg/cm2). Using the Drinking Water Surveillance Program data in Ontario, chronic daily intakes of trihalomethanes were estimated to be 9.40 × 10?7 (1.85 × 10?7–1.65 × 10?6), 3.89 × 10?6 (7.11 × 10?7–2.33 × 10?5), and 1.40 × 10?6 (4.0 × 10?7–1.77 × 10?6) mg/kg/day in Toronto, Ottawa, and Hamilton, respectively. The findings can be useful in understanding THMs exposure and risk through dermal pathway. 相似文献
108.
E. Hampton Sessions Michael Smolinski Bo Wang Bozena Frackowiak Sarwat Chowdhury Yan Yin Yen Ting Chen Claudia Ruiz Li Lin Jennifer Pocas Thomas Schröter Michael D. Cameron Philip LoGrasso Yangbo Feng Thomas D. Bannister 《Bioorganic & medicinal chemistry letters》2010,20(6):1939-1943
Rho Kinase (ROCK) is a serine/threonine kinase whose inhibition could prove beneficial in numerous therapeutic areas. We have developed a promising class of ATP-competitive inhibitors based upon a benzimidazole scaffold, which show excellent potency toward ROCK (IC50 <10 nM). This report details the optimization of selectivity for ROCK over other related kinases such as Protein kinase A (PKA). 相似文献
109.
Sajal Chakraborti Animesh Chowdhury Pulak Kar Partha Das Soni Shaikh Soumitra Roy Tapati Chakraborti 《Archives of biochemistry and biophysics》2009,487(2):123-130
Treatment of bovine pulmonary smooth muscle cells with the TxA2 mimetic, U46619 stimulated [Ca2+]i, which was inhibited upon pretreatment with apocynin (NADPH oxidase inhibitor). Pretreatment with cromakalim (KV channel opener) or nifedepine (L-VOCC inhibitor) inhibited U46619 induced increase in [Ca2+]i, indicating a role of KV-LVOCC axis in this scenario. Neither cromakalim nor nifedepine inhibited U46619 induced increase in NADPH oxidase activity, suggesting that the NADPH oxidase activation is proximal to the KV-LVOCC axis in the cells. Pretreatment with calphostin C (PKC inhibitor) markedly reduced U46619 induced increase in NADPH oxidase activity and [Ca2+]i in the cells. Calphostin C pretreatment also markedly reduced p47phox phosphorylation and translocation to the membrane and association with p22phox, a component of Cyt.b558 of NADPH oxidase in the membrane. Overall, PKC plays an important role in NADPH oxidase derived O2−-mediated regulation of KV-LVOCC axis leading to an increase in [Ca2+]i by U46619 in the cells. 相似文献
110.