Response Surface Methodology for Optimizing the Bovine Serum Albumin Fibrillation

Amyloid fibrils are considered as nanostructures that could be formed by ordered self-assembly of the partially-folded states of many different peptides or proteins. In this study, bovine serum albumin was used as a model protein whose ordered aggregation (fibrillation) was optimized. Response surface methodology (RSM) was used in a design that contained a total of 30 experimental trials. The first 24 were organized in a factorial design and from 25 to 30 involved the replications of the central points. Data obtained from RSM were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation. Subsequent testing of the suggested experimental parameters was done in vitro with Congo red spectrophotometric assay. Protein concentration, pH, temperature and time of incubation were the variables used in this study. Responses were assessed by measuring absorbance in 540?nm (characteristic of amyloid formation) and maximal wavelength. Concomitant effects of variables were assessed in surface plots that each considered two of the variables. Interestingly, the pattern obtained by monitoring absorbance at 540?nm and absorbance in maximal wavelength were identical in most cases. We are reporting the optimum concentration of protein, pH, temperature and time at 5?mg?ml^?1, 3.02 and 72?°C and 48?h, respectively. Our findings suggest that use of Congo red spectrophotometric test, as a simple and affordable assay could be suggested as a first test for assessing fibril formation of proteins. Absorbance in maximal wavelength is recommended as a significant indication of fibril formation.     

Lactic acid production by loofah-immobilized Rhizopus oryzae through one-step fermentation process using starch substrate

Rhizopus oryzae PTCC 5263 capacity in synthesis of lactic acid (LA) from 10 g/l of soluble potato starch was determined using one-step fermentation process. Pellets were the favorable growing form of the free cells. The extent of the natural ability of the test fungus on biofilm formation on loofah sponge was examined by immobilizing R. oryzae (LIRO). The maximum LA concentration for the free cells and LIRO within 96 h was 3 and 4 g/l, respectively. In terms of specific starch utilization rate (\(q_{\text{s}}\)) and specific LA formation (\(q_{\text{p}}\)), LIRO performed more favorably compared to the free cells (\(q_{{{\text{s}}_{\text{F}} }} > q_{{{\text{s}}_{\text{LIRO}} }}\) and \(q_{{{\text{p}}_{\text{F}} }} < q_{{{\text{p}}_{\text{LIRO}} }}\)). Cell immobilization strategy was undertaken for the column reactor studies based on the statistically optimized levels of the inoculum size and temperature. Maximum production of the LA by the LIRO using an airlift reactor with net draft tube was 5 g/l obtainable within 48 h.

     

iPSC modeling of stage-specific leukemogenesis reveals BAALC as a key oncogene in severe congenital neutropenia

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Breast Tumor Targeting in Mice Bearing 4T1 Tumor with Labeled CXCR4 Antagonist Analogue

International Journal of Peptide Research and Therapeutics - Chemokine receptor belongs to G-protein-coupled cell-surface receptors. CXCR4 as a chemokine receptor is over-expressed in many type of...     

Stimulating Role of Toxoids-laden Liposomes in Oral Immunization against Diphtheria and Tetanus Infections

Liposomes have been produced by injecting an ether solution of a mixture of lecithin and cholesterol into a diluted solution of prewarmed diphtheria and tetanus toxoids followed by elimination of the stream of ether vapour by vacuum.In a preliminary study, adjuvant effects of liposomes on the systemic and mucosal immune response have been studied. When a mixture of diphtheria toxoid (DT) and tetanus toxoid (TT) entrapped in liposomes were administered parenterally or orally in rabbit, a significant rise of specific antibodies against both toxoids was noticed. In monkeys receiving a mixture of DT and TT entrapped in liposomes orally, the antibody response after two and three ingestions of this product was mild but when liposomes containing toxoids were adsorbed with aluminium hydroxide in a similar experiment, a significant rise in the specific antibody response in monkey against both toxoids was recorded. Adult volunteers, similarly receiving a mixture of DT and TT, entrapped in liposomes and adsorbed with aluminium hydroxide have shown a significant rise in specific circulating antitoxins. In order to compare the efficacy of this technique of human oral immunization with the previous method, whereby a plant medicinal seed (LRS) was used as adjuvant in oral immunization of man, a second group of volunteers were simultaneously and similarly treated as suggested previously. The comparative results are discussed in the present report.