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Extracellular lipase production byRhizopus arrhizus was increased by mutant selection from 130 to 670 μmol FFA per mL per min using UV radiation and aziridine treatment. The
produced lipase was purified 720-fold by ammonium sulfate fractionation and Sephadex G-100 gel filtration. The molar mass
of the produced lipase was determined to be approximately 67 kDa which comigrated with bovine serum albumin in both a Sephadex
G-100 column and SDS-PAGE. 相似文献
44.
Sudeshna Chowdhury Shakuntala Ghorai Samudra Prosad Banik Swagata Pal Soumen Basak Suman Khowala 《Process Biochemistry》2009,44(10):1075-1082
An extracellular sucrase from the culture filtrate of filamentous basidiomycota Termitomyces clypeatus grown on high sucrose (5%, w/v) was purified by gel filtration chromatography, ion exchange chromatography and HPGPLC. The biochemical properties, molecular weight and conformation of sucrase produced were significantly different from the sucrase earlier purified from sucrose (1%, w/v) medium in the fungus. Purified sucrase was characterized as a low molecular weight protein of 13.5 kDa as approximated by SDS-PAGE and HPGPLC and exhibited predominantly random coil conformation in far-UV CD spectra. The enzyme was optimally active at 47 °C and pH 5.0. Km and catalytic activity of the enzyme for sucrose were found to be 3.5 mM and 1.06 U/mg/mM, respectively. The enzyme was maximally active towards sucrose than to raffinose and sucrase activity was significantly inhibited by bivalent metal ions and reducing group agents. The results indicated that due to changes in aggregation pattern, molecular organization of purified sucrase, produced in high sucrose medium, was altered and was different from the previously reported enzyme. This is the first report of a sucrase of such low size showing activity. 相似文献
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We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus. 相似文献
47.
Samantaray S Smith JA Das A Matzelle DD Varma AK Ray SK Banik NL 《Neurochemical research》2011,36(10):1809-1816
Spinal cord injury (SCI), depending on the severity of injury, leads to neurological dysfunction and paralysis. Methylprednisolone,
the only currently available therapy renders limited protection in SCI. Therefore, other therapeutic agents must be tested
to maximize neuroprotection and functional recovery. Previous data from our laboratory indicate that estrogen (17β-estradiol)
at a high dose may attenuate multiple damaging pathways involved in SCI and improve locomotor outcome. Since use of high dose
estrogen may have detrimental side effects and therefore may never be used in the clinic, the current study investigated the
efficacy of this steroid hormone at very low doses in SCI. In particular, we tested the impact of dosing (1–10 μg/kg), mode
of delivery (intravenous vs. osmotic pump), and delay in estrogen application (15 min–4 h post-SCI) on microgliosis and neuronal
death in acute SCI in rats. Treatment with 17β-estradiol (1–10 μg/kg) significantly reduced microglial activation and also
attenuated apoptosis of neurons compared to untreated SCI animals. The attenuation of cell death and inflammation by estrogen
was observed regardless of mode and time of delivery following injury. These findings suggest estrogen as a potential agent
for the treatment of individuals with SCI. 相似文献
48.
White-nose syndrome (WNS) is an emerging disease causing unprecedented morbidity and mortality among bats in eastern North America. The disease is characterized by cutaneous infection of hibernating bats by the psychrophilic fungus Geomyces destructans. Detection of G. destructans in environments occupied by bats will be critical for WNS surveillance, management and characterization of the fungal lifecycle. We initiated an rRNA gene region-based molecular survey to characterize the distribution of G. destructans in soil samples collected from bat hibernacula in the eastern United States with an existing PCR test. Although this test did not specifically detect G. destructans in soil samples based on a presence/absence metric, it did favor amplification of DNA from putative Geomyces species. Cloning and sequencing of PCR products amplified from 24 soil samples revealed 74 unique sequence variants representing 12 clades. Clones with exact sequence matches to G. destructans were identified in three of 19 soil samples from hibernacula in states where WNS is known to occur. Geomyces destructans was not identified in an additional five samples collected outside the region where WNS has been documented. This study highlights the diversity of putative Geomyces spp. in soil from bat hibernacula and indicates that further research is needed to better define the taxonomy of this genus and to develop enhanced diagnostic tests for rapid and specific detection of G. destructans in environmental samples. 相似文献
49.
Zhuo Ma Sukalyani Banik Harshita Rane Vanessa T. Mora Seham M. Rabadi Christopher R. Doyle David G. Thanassi Meenakshi Malik 《Molecular microbiology》2014,91(5):976-995
Francisella tularensis is a category A biodefence agent that causes a fatal human disease known as tularaemia. The pathogenicity of F. tularensis depends on its ability to persist inside host immune cells primarily by resisting an attack from host‐generated reactive oxygen and nitrogen species (ROS/RNS). Based on the ability of F. tularensis to resist high ROS/RNS levels, we have hypothesized that additional unknown factors act in conjunction with known antioxidant defences to render ROS resistance. By screening a transposon insertion library of F. tularensis LVS in the presence of hydrogen peroxide, we have identified an oxidant‐sensitive mutant in putative EmrA1 (FTL_0687) secretion protein. The results demonstrate that the emrA1 mutant is highly sensitive to oxidants and several antimicrobial agents, and exhibits diminished intramacrophage growth that can be restored to wild‐type F. tularensis LVS levels by either transcomplementation, inhibition of ROS generation or infection in NADPH oxidase deficient (gp91Phox?/?) macrophages. The emrA1 mutant is attenuated for virulence, which is restored by infection in gp91Phox?/? mice. Further, EmrA1 contributes to oxidative stress resistance by affecting secretion of Francisella antioxidant enzymes SodB and KatG. This study exposes unique links between transporter activity and the antioxidant defence mechanisms of F. tularensis. 相似文献
50.
Reema Roshan Shruti Shridhar Mayuresh A. Sarangdhar Arpita Banik Mrinal Chawla Manali Garg Vijay PAL Singh Beena Pillai 《RNA (New York, N.Y.)》2014,20(8):1287-1297
Several microRNAs have been implicated in neurogenesis, neuronal differentiation, neurodevelopment, and memory. Development of miRNA-based therapeutics, however, needs tools for effective miRNA modulation, tissue-specific delivery, and in vivo evidence of functional effects following the knockdown of miRNA. Expression of miR-29a is reduced in patients and animal models of several neurodegenerative disorders, including Alzheimer''s disease, Huntington''s disease, and spinocerebellar ataxias. The temporal expression pattern of miR-29b during development also correlates with its protective role in neuronal survival. Here, we report the cellular and behavioral effect of in vivo, brain-specific knockdown of miR-29. We delivered specific anti-miRNAs to the mouse brain using a neurotropic peptide, thus overcoming the blood-brain-barrier and restricting the effect of knockdown to the neuronal cells. Large regions of the hippocampus and cerebellum showed massive cell death, reiterating the role of miR-29 in neuronal survival. The mice showed characteristic features of ataxia, including reduced step length. However, the apoptotic targets of miR-29, such as Puma, Bim, Bak, or Bace1, failed to show expected levels of up-regulation in mice, following knockdown of miR-29. In contrast, another miR-29 target, voltage-dependent anion channel1 (VDAC1), was found to be induced several fold in the hippocampus, cerebellum, and cortex of mice following miRNA knockdown. Partial restoration of apoptosis was achieved by down-regulation of VDAC1 in miR-29 knockdown cells. Our study suggests that regulation of VDAC1 expression by miR-29 is an important determinant of neuronal cell survival in the brain. Loss of miR-29 results in dysregulation of VDAC1, neuronal cell death, and an ataxic phenotype. 相似文献