Papers by Zafar Navalgund
Atrazine is ubiquitously used broad-spectrum herbicide to control the weeds in agriculture. The p... more Atrazine is ubiquitously used broad-spectrum herbicide to control the weeds in agriculture. The present study aimed to evaluate the acute toxicity and immunotoxicity of Atrazine in two ecologically and economically important bivalves. Acute toxicity of atrazine evaluated in triplicates by taking control and six experimental groups each comprising of 30 animals and treated with a range of atrazine from 2 PPM to 12 PPM for 96 hours. Mortalities were recorded for every 24 hours until 96 hours and data analyzed by one-way ANOVA and Dunnett T-test. The results indicated a significant increase in mortalities with increase in dose and time of exposure in both species. The values of LC50 were determined as 6.10 PPM and 4.90 PPM respectively for Perna viridis and Paphia malabarica. Furthermore, the immunotoxic potential of atrazine assessed by treating mussels and clams with the five sub-lethal doses of atrazine for 14 days and quantifying the viability of hemocytes by using simple yet relia...
Bioscience Biotechnology Research Communications, 2020
Present study is based on the concept of green synthesis of gold nanoparticles using cathepsin B ... more Present study is based on the concept of green synthesis of gold nanoparticles using cathepsin B and functionalization of cathepsin B on their surface which are involved in cancer. Classical citrate method was used to reduce chloroauric acid with tri-sodium citrate in an aqueous solution to produce citrate gold nanoparticles (C-GNPs). Further, these nanoparticles were immobilized with cathepsin B in order to study the conformation changes during and after function alization. The C-GNPs and cathepsin B immobilized gold nanoparticles (Cat-B-GNPs) were characterized by UV-VIS spectroscopy, TEM, DLS, Zeta potential, SEM and FTIR to confirm the size, functional group interactions, production, stability, crystalline nature, size and shape distribution. However, FTIR studies confirmed the attachment of cathepsin B in the gold nanoparticles. The variation in 2D and 3D conformation of cathepsin B during immobilization was studied by Circular Dichroism and Fluorescence spectroscopy, respectively. It was observed that total changes in αhelix, stand, and turn is 45.41%, 34.75%, 76%, respectively. After immobilization, a 54.91% changes in tertiary structure was found. The change in 2D & 3D conformation of cathepsin B after immobilization may improve cathepsin B potency which would be verified by enzyme kinetics inhibition. Results showed that E-64 significantly inhibited Cat-B-GNPs activity with an IC 50 of 4.88 µM and inhibition was a non-competitive type of inhibition with a K i of 5.09 µM. Michaelis-Menten constant K m of cathepsins B and Cat-B-GNPs were determined by using Z-Phe-Arg-AMC as substrates and E-64 as a model inhibitor.
Indian journal of experimental biology, 2016
Viral diseases are not only responsible for health related issues but also exert pressure on the ... more Viral diseases are not only responsible for health related issues but also exert pressure on the State economy. Tropical and subtropical countries have more prevalence of virus associated pathological conditions such as chickenpox, adenovirus related infections, dengue, chickengunya, infectious mononucleosis, etc. Treatment options with effective antiviral drugs are limited and are unfortunately not free from undesirable effects. The Asian Green Mussel, Perna viridis (Linn.) (Mytilidae) are not only important for their evolutionary significance, high caloric index, ecological role in the sequestration of environmental pollutants especially heavy metals, but also are potential source for extraction of therapeutic and bioactive compounds. On the other hand, generally in bivalves, virus mediated mortality is not uncommon. In this study, we made a maiden attempt of exploring DNAse like bioactivity for natural non-protenacious compound(s) extracted from P. viridis. Crude Methanol Extract...
bioRxiv, 2021
India is known for its rich biodiversity and is fortunate to have several endemic species from di... more India is known for its rich biodiversity and is fortunate to have several endemic species from different classes of vertebrates. India is home to 7.5% of the global fish diversity, with 91 endemic species of ray finned fishes, the actinopterygians. Some fish species have never been reported until recently, one such example is the long-horned Cowfish (Ostracidae), best known for inhabiting only certain areas of the Indo-Pacific oceans. However, this fish has been reported from Bay of Bengal, Costs of Goa and Lakshadweep. This is the first time this fish has been found on the Coasts of Karnataka, west coast of India. Given its morphology, the migration seems highly improbable since it can only endure lethargic swimming. In this article, we have explored the role of other external forces that could have contributed to its range extension in the east and west coast of India. In this paper we are exploring the role of Super Cyclones as a vital force in determining the expansion of its ra...
Present study is based on the concept of green synthesis of gold nanoparticles using cathepsin B ... more Present study is based on the concept of green synthesis of gold nanoparticles using cathepsin B and functionalization of cathepsin B on their surface which are involved in cancer. Classical citrate method was used to reduce chloroauric acid with tri-sodium citrate in an aqueous solution to produce citrate gold nanoparticles (C-GNPs). Further, these nanoparticles were immobilized with cathepsin B in order to study the conformation changes during and after function alization. The C-GNPs and cathepsin B immobilized gold nanoparticles (Cat-B-GNPs) were characterized by UV-VIS spectroscopy, TEM, DLS, Zeta potential, SEM and FTIR to confirm the size, functional group interactions, production, stability, crystalline nature, size and shape distribution. However, FTIR studies confirmed the attachment of cathepsin B in the gold nanoparticles. The variation in 2D and 3D conformation of cathepsin B during immobilization was studied by Circular Dichroism and Fluorescence spectroscopy, respectively. It was observed that total changes in αhelix, stand, and turn is 45.41%, 34.75%, 76%, respectively. After immobilization, a 54.91% changes in tertiary structure was found. The change in 2D & 3D conformation of cathepsin B after immobilization may improve cathepsin B potency which would be verified by enzyme kinetics inhibition. Results showed that E-64 significantly inhibited Cat-B-GNPs activity with an IC 50 of 4.88 µM and inhibition was a non-competitive type of inhibition with a K i of 5.09 µM. Michaelis-Menten constant K m of cathepsins B and Cat-B-GNPs were determined by using Z-Phe-Arg-AMC as substrates and E-64 as a model inhibitor.
Viral diseases are not only responsible for health related issues but also exert pressure on the ... more Viral diseases are not only responsible for health related issues but also exert pressure on the State economy. Tropical and subtropical countries have more prevalence of virus associated pathological conditions such as chickenpox, adenovirus related infections, dengue, chickengunya, infectious mononucleosis, etc. Treatment options with effective antiviral drugs are limited and are unfortunately not free from undesirable effects. The Asian Green Mussel, Perna viridis (Linn.) (Mytilidae) are not only important for their evolutionary significance, high caloric index, ecological role in the sequestration of environmental pollutants especially heavy metals, but also are potential source for extraction of therapeutic and bioactive compounds. On the other hand, generally in bivalves, virus mediated mortality is not uncommon. In this study, we made a maiden attempt of exploring DNAse like bioactivity for natural non-protenacious compound(s) extracted from P. viridis. Crude Methanol Extract (CME) of soft tissue of P. viridis and subsequently its partially purified component (PPC) possess exceptional ability to degrade indiscriminately both low and high molecular weight DNAs. In vitro digestions for1, 2 and 3 h with CME and PPC were found to be comparable to commercial (Sigma-Aldrich) enzyme, DNase I. Bioactive assays conducted to evaluate antimicrobial property, have shown that CME and PPC exclusively inhibit viral propagation. Nonetheless, CME & PPC have no effect on the propagation of bacteria (0 mm ZOI). These results indicate the possibility of a source of potential antiviral drug against DNA Group I viruses. Although our study does not provide any data to correlate to any physiological functions of these substances but provides a clue towards an important role in the biology of mussels. Any conclusion at this stage is premature. However, taking into consideration the significantly high virus mediated mortality in bivalves and the antiviral bioactivity of these substances, it appears that mussels have evolved some mechanisms to counteract some viruses.
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Papers by Zafar Navalgund