Immunopurification and characterization of a rape (Brassica napus L.) seedling lipase

Lipase or triacylglycerol acylhydrolase (E.C.3.1.1.3) was purified to homogeneity from rapeseed-germinated cotyledons (Brassica napus L.). The purification scheme involved homogenization, centrifugation, ultracentrifugation and affinity chromatography using polyclonal antibodies raised against porcine pancreatic lipase. The purified rapeseed lipase was homogenous and did not contain contaminating proteins detectable by SDS-PAGE and HPLC analysis. The specific activity of the purified preparation was increased about 1950 times, with an overall yield of 35%. The rapeseed lipase was found to be a cytosoluble, glycosylated and heat-labile serine-hydrolase. It was monomeric with a molecular mass of 38 kDa and a pH of 6.6. The purification method used in the present work is rapid, simple, and yields highly purified lipase. It may therefore be applicable in the purification of other uncharacterized plant lipases.Keywords: Brassica napus L., immuno-affinity, lipase, purification, triacylglycerol acyl hydrolaseAfrican Journal of Biotechnology Vol. 12(21), pp. 3224-323

Fenugreek proteins and their hydrolysates prevent hypercholesterolemia and enhance the HDL antioxidant properties in rats

Purpose This paper aims to investigate the in vivo hypocholesterolemic property of fenugreek proteins (FP), Purafect-fenugreek protein hydrolysate (PFPH) and Esperase-fenugreek protein hydrolysate (EFPH) on high cholesterol (HC)-fed rats. Design/methodology/approach Rats were randomized into five groups: four were fed for four weeks a hypercholesterolemic diet and the tested products were given by gavage. The fifth group was taken as control (C) receiving the same diet without cholesterol. Findings Results showed that the elevated aspartate aminotransferase activity in HC group plasma was significantly corrected by FP and EFPH administration (-33 per cent; p = 0.0003). HC liver lipids and total cholesterol (TC) contents were not markedly affected by FP and EFPH. However, liver triglycerides (TG) contents trended to decrease in FP rats vs HC (p = 0.07), while, the TG decrease was significant in groups fed the proteins hydrolysates (p = 0.02). On the other hand, serum TC and TG decreased by 53 per cent (p = 0.0003) and 20 per cent (p = 0.04), respectively, in FP treated rats compared to HC group. This decrease was associated with a high fecal cholesterol excretion (2.5-fold higher in FP vs HC; p = 0.0001). Likewise, EFPH-treated rats exhibited lower TC compared to HC rats (p = 0.004). The very low density lipoprotins was the main affected fraction in these two groups, while there were no significant difference in apolipoproteins (Apo) B, A-I and A-IV contents between the different groups, except in FP group, where Apo A-I and A-IV decreased by 26 and 17 per cent, respectively, compared to C rats (p = 0.02). The high density lipoproteins (HDL) of rats treated with proteins hydrolysates showed a better antioxidant property compared to those of HC rats, which was accompanied with an increase in paraoxonase activity when compared to HC group. Originality/value Unlike PFPH which had almost no effect, FPs and EFPH could constitute a nutraceutical ingredient in cardiovascular disease management

Dynamics of the Multiplicity of Cellular Infection in a Plant Virus

Recombination, complementation and competition profoundly influence virus evolution and epidemiology. Since viruses are intracellular parasites, the basic parameter determining the potential for such interactions is the multiplicity of cellular infection (cellular MOI), i.e. the number of viral genome units that effectively infect a cell. The cellular MOI values that prevail in host organisms have rarely been investigated, and whether they remain constant or change widely during host invasion is totally unknown. Here, we fill this experimental gap by presenting the first detailed analysis of the dynamics of the cellular MOI during colonization of a host plant by a virus. Our results reveal ample variations between different leaf levels during the course of infection, with values starting close to 2 and increasing up to 13 before decreasing to initial levels in the latest infection stages. By revealing wide dynamic changes throughout a single infection, we here illustrate the existence of complex scenarios where the opportunity for recombination, complementation and competition among viral genomes changes greatly at different infection phases and at different locations within a multi-cellular host

Quasispecies Spatial Models for RNA Viruses with Different Replication Modes and Infection Strategies

Empirical observations and theoretical studies suggest that viruses may use different replication strategies to amplify their genomes, which impact the dynamics of mutation accumulation in viral populations and therefore, their fitness and virulence. Similarly, during natural infections, viruses replicate and infect cells that are rarely in suspension but spatially organized. Surprisingly, most quasispecies models of virus replication have ignored these two phenomena. In order to study these two viral characteristics, we have developed stochastic cellular automata models that simulate two different modes of replication (geometric vs stamping machine) for quasispecies replicating and spreading on a two-dimensional space. Furthermore, we explored these two replication models considering epistatic fitness landscapes (antagonistic vs synergistic) and different scenarios for cell-to-cell spread, one with free superinfection and another with superinfection inhibition. We found that the master sequences for populations replicating geometrically and with antagonistic fitness effects vanished at low critical mutation rates. By contrast, the highest critical mutation rate was observed for populations replicating geometrically but with a synergistic fitness landscape. Our simulations also showed that for stamping machine replication and antagonistic epistasis, a combination that appears to be common among plant viruses, populations further increased their robustness by inhibiting superinfection. We have also shown that the mode of replication strongly influenced the linkage between viral loci, which rapidly reached linkage equilibrium at increasing mutations for geometric replication. We also found that the strategy that minimized the time required to spread over the whole space was the stamping machine with antagonistic epistasis among mutations. Finally, our simulations revealed that the multiplicity of infection fluctuated but generically increased along time

Wound healing and in vitro antioxidant activities of lipopeptidesmixture produced by Bacillus mojavensis A21

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