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1.
Benzamidine, an inhibitor of serine proteases, was used as an affinity ligand for the purification of aspartyl protease from culture filtrate of Rhizomucor miehei. The two step purification protocol (ion-exchange and affinity chromatography) resulted in a homogenous enzyme preparation with seven-fold purification and a final recovery of 22%. The purified enzyme was free of brown pigmentation, a factor inherently associated with the enzyme; it was stable and active at acidic pH (optimum pH 4.1 for proteolytic activity and 5.6 for milk clotting activity). The significant positive characteristic of the enzyme is its comparatively lower thermostability; the enzyme was comparable to calf rennet in its properties of thermostability, milk-clotting to proteolytic activity ratio and sensitivity to CaCl2. Limited protease digestion of the purified enzyme with proteinase K yielded a 20kDa fragment as shown by SDS–PAGE. Native gel electrophoresis of the digest showed an additional peak of activity corresponding to the 20kDa fragment on SDS–PAGE, this fragment retained both milk-clotting and proteolytic activities. It was also inhibited by pepstatin A and hence it is presumed that this fragment contained the active site of the enzyme. 相似文献
2.
Lavanya Prathap Selvaraj Jayaraman Anitha Roy Preetha Santhakumar M Jeevitha 《Bioinformation》2021,17(2):363
Inflammation is a process triggered by pro-inflammatory cytokines and anti-inflammatory molecules. Therefore, it is of interest to document the anti-inflammatory activity of Stachydrine and Sakuranetin against the inflammatory target proteins IL-6 and TNF-α by using molecular docking analysis. Both compounds showed good binding features with the selected target proteins. Compared to Sakuranetin, the Stachydrine have low binding energy and good hydrogen bond interactions. Hence, data show that Stachydrine possessed high and specific inhibitory activity on tumor necrosis factor-α and interleukin-6. 相似文献
3.
The beneficial effects of magnesium supplementation in pathological situations is well known, but the myocardial response
to a nominal decrease in the level of magnesium has received relatively little attention. Hypomagnesemia can occur as chronic
or acute manifestation of physiological changes, pathological conditions, or pharmacological interventions. Experimental interest
was focused on the mechanical changes in adult rat heart myocytes following variation in extracellular Mg2+. Isolated cells were exposed to different levels of extracellular Mg2+ and the amplitude and rate of contraction were measured as a function of change in cell length using a video-based edge-detection
system. Investigations have revealed that variation in the level of Mg2+ within physiological limits leads to mechanical changes. A decrease in the level of extracellular Mg2+ was accompanied by a significant increase in contractile amplitude and decrease in the velocities of contraction and relaxation.
The contractile amplitude measured as percentage shortening were 3.08 ± 0.19%, 4.62 ± 0.19% and 6.9 ± 0.40%, respectively,
on exposure to 1.8, 0.8, and 0.48 mM Mg, and the corresponding velocities of contraction and relaxation normalized to amplitude were 0.54 ± 0.02, 0.40 ± 0.03,
0.31 ± 0.03 and 0.47 ± 0.02, 0.35 ± 0.02, 0.24 ± 0.02. The variations in contractile parameters associated with the change
in the level of Mg were statistically significant (p < 0.01). Variation in the contractile properties associated with change in extracellular Mg2+ may be effected by alteration in Ca2+ transients. 相似文献
4.
Preetha Santhakumar Lavanya Prathap Anitha Roy Selvaraj Jayaraman M Jeevitha 《Bioinformation》2021,17(2):356
It is of interest to document the molecular docking analysis based binding data of furfural and isoginkgetin with heme oxygenase I and PPARγ in the context of inflammation for further consideration in drug design and development. 相似文献
5.
Joseph D. Layne Preetha Shridas Nancy R. Webb 《The Journal of biological chemistry》2015,290(12):7851-7860
Group X secretory phospholipase A2 (GX sPLA2) hydrolyzes mammalian cell membranes, liberating free fatty acids and lysophospholipids. GX sPLA2 is produced as a pro-enzyme (pro-GX sPLA2) that contains an N-terminal 11-amino acid propeptide ending in a dibasic motif, suggesting cleavage by a furin-like proprotein convertase (PC). Although propeptide cleavage is clearly required for enzymatic activity, the protease(s) responsible for pro-GX sPLA2 activation have not been identified. We previously reported that GX sPLA2 negatively regulates adrenal glucocorticoid production, likely by suppressing liver X receptor-mediated activation of steroidogenic acute regulatory protein expression. In this study, using a FLAG epitope-tagged pro-GX sPLA2 expression construct (FLAG-pro-GX sPLA2), we determined that adrenocorticotropic hormone (ACTH) enhanced FLAG-pro-GX sPLA2 processing and phospholipase activity secreted by Y1 adrenal cells. ACTH increased the expression of furin and PCSK6, but not other members of the PC family, in Y1 cells. Overexpression of furin and PCSK6 in HEK 293 cells significantly enhanced FLAG-pro-GX sPLA2 processing, whereas siRNA-mediated knockdown of both PCs almost completely abolished FLAG-pro-GX sPLA2 processing in Y1 cells. Expression of either furin or PCSK6 enhanced the ability of GX sPLA2 to suppress liver X receptor reporter activity. The PC inhibitor decanoyl-Arg-Val-Lys-Arg-chloromethyl ketone significantly suppressed FLAG-pro-GX sPLA2 processing and sPLA2 activity in Y1 cells, and it significantly attenuated GX sPLA2-dependent inhibition of steroidogenic acute regulatory protein expression and progesterone production. These findings provide strong evidence that pro-GX sPLA2 is a substrate for furin and PCSK6 proteolytic processing and define a novel mechanism for regulating corticosteroid production in adrenal cells. 相似文献
6.
Cornelis MC Monda KL Yu K Paynter N Azzato EM Bennett SN Berndt SI Boerwinkle E Chanock S Chatterjee N Couper D Curhan G Heiss G Hu FB Hunter DJ Jacobs K Jensen MK Kraft P Landi MT Nettleton JA Purdue MP Rajaraman P Rimm EB Rose LM Rothman N Silverman D Stolzenberg-Solomon R Subar A Yeager M Chasman DI van Dam RM Caporaso NE 《PLoS genetics》2011,7(4):e1002033
We report the first genome-wide association study of habitual caffeine intake. We included 47,341 individuals of European descent based on five population-based studies within the United States. In a meta-analysis adjusted for age, sex, smoking, and eigenvectors of population variation, two loci achieved genome-wide significance: 7p21 (P = 2.4 × 10(-19)), near AHR, and 15q24 (P = 5.2 × 10(-14)), between CYP1A1 and CYP1A2. Both the AHR and CYP1A2 genes are biologically plausible candidates as CYP1A2 metabolizes caffeine and AHR regulates CYP1A2. 相似文献
7.
G. Mustafa Saifi Preetha Tilak Reiner Veitia I. Manorama Thomas Avirachan Tharapel Ken Mcelreavey Mark Fellous H. Sharat Chandra 《Journal of genetics》1999,78(3):157-161
We describe a novel mutation in the coding region of theSRY gene in a 46, XY female with Swyer syndrome. Analysis ofSRY was carried out by direct sequencing of a 780-bp PCR product that included theSRY open reading frame (ORF). This revealed the presence of a point mutation, ins 108A, in the coding region 5’ to the HMG box which results in a frame shift and premature termination of the encoded protein. No other mutation was found in theSRY ORF. We infer that sex reversal in this individual is a result of this insertion. In none of the 13 other 46, XY females that were studied was a mutation detected inSRY, confirming earlier findings that most cases of XY femaleness are due to causes other than mutation inSRY. These observations and those of others are discussed in relation to the aetiology of XY sex reversal. 相似文献
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9.
The ratio of milk-clotting activity to proteolytic activity (MC/PA) was used as an index to determine the quality of milk-clotting enzyme. Solid-state fermentation on wheat bran for 5 days at room temperature gave optimal production for enzyme by Rhizomucor miehei and R. pusillus. A ratio of wheat bran to moisture of 1:0.6 (w/v) gave best results. Adding skim milk powder to the media of R. miehei did not improve the MC/PA ratio but 4% (w/w) of the powder did improve the ratio with R. pusillus. Co-cultivation of R. miehei with R. pusillus did not change the MC/PA ratio.The authors are with the Department of Biotechnogy, Bharathiar University. Coimbatore-641 046 India 相似文献
10.
Farzana Walcott Preetha Rajaraman Shahinaz M. Gadalla Peter D. Inskip Mark P. Purdue Demetrius Albanes Esther Orr Immaculata De Vivo Sharon A. Savage 《Cancer epidemiology》2013,37(6):935-938
BackgroundTelomere length in blood or buccal cell DNA has been associated with risk of various cancers. Glioma can be a highly malignant brain tumor and has few known risk factors. Genetic variants in or near RTEL1 and TERT, key components of telomere biology, are associated with glioma risk. Therefore, we evaluated the association between relative telomere length (RTL) and glioma in a prospective study.Materials and methodsWe performed a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. RTL was determined by quantitative PCR on blood or buccal cell DNA obtained at least 2 years prior to diagnosis from 101 individuals with glioma cases. Healthy controls (n = 198) were matched to cases (2:1) on age, gender, smoking status, calendar year, and DNA source. Conditional logistic regression was used to investigate the association between RTL and glioma.ResultsAs expected, RTL declined with increasing age in both cases and controls. There was no statistically significant association between RTL and glioma overall. An analysis stratified by gender suggested that short RTL (1st tertile) in males was associated with glioma (odds ratio, [OR] = 2.29, 95% confidence interval [CI] 1.02–5.11); this association was not observed for females (OR = 0.41, 95% CI 0.14–1.17).ConclusionsThis prospective study did not identify significant associations between RTL and glioma risk, but there may be gender-specific differences. Larger, prospective studies are needed to evaluate these findings. 相似文献