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Reference Protein (reference + protein)
Selected AbstractsDetermination of Total Protein Content in Gelatin Solutions with the Lowry or Biuret AssayJOURNAL OF FOOD SCIENCE, Issue 8 2006P. Zhou ABSTRACT:, Gelatins can be obtained from different sources and prepared using different processes, and the end product gelatin may vary in amino acid composition and molecular weight distribution. In the present study, the variation in "protein color" development among gelatins in colorimetric total protein content measurements was investigated at 540 nm using the Biuret assay and at 650 nm using the Lowry assay, with bovine serum albumin as the reference protein. In both the Biuret and Lowry assays, the color response varied significantly among gelatins. The difference in imino acid content was the major factor responsible for this variation, which probably influenced the gelatin helix , coil phase transition and resulted in the difference in gelatin associate state. Based on their "protein color" development abilities in both Biuret and Lowry, gelatins were classified into 2 major groups with the hierarchical cluster analysis: 1 group included all cold water fish gelatins, while the other included gelatins from warm water fish, avian, and mammalian species. [source] Nutritional study of raw and popped seed proteins of Amaranthus caudatus L and Amaranthuscruentus LJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2004Tamer H Gamel Abstract The nutritional value of raw and popped (similar to popcorn preparation) seed proteins of two amaranth species, Amaranthus caudatus L and A cruentus L, was investigated. After popping, the true protein content in A caudatus and A cruentus decreased by 9 and 13% respectively. Among the amino acids, the loss of tyrosine due to the popping effect was the highest, followed by phenylalanine and methionine. Leucine was the first limiting amino acid in the raw samples, followed by lysine, while the reverse order was observed in the popped samples. The in vivo protein quality of raw and popped seeds was tested with male weanling rats and compared with wheat flour and casein samples. There was no difference between the in vivo digestibility of the raw and the popped seeds, although the in vitro digestibility was slightly higher for the popped samples. The protein efficiency ratio (PER) for all the amaranth seed samples was higher than that for the wheat sample, while the PER for the raw amaranth seed samples was close to that for the casein reference protein. The rat blood serum levels of total cholesterol, triglycerides and high-density lipoprotein cholesterol for all the amaranth samples were lower than those for the reference protein, while the wheat flour sample showed the lowest values. Copyright © 2004 Society of Chemical Industry [source] Disaggregation of high-molecular weight species during downstream processing to recover functional monomerBIOTECHNOLOGY PROGRESS, Issue 3 2010Xuankuo Xu Abstract The use of chaotropic agents to recover functional monomeric material was investigated for the downstream purification of an Fc-fusion protein containing high levels of high-molecular weight (HMW) species. In batch studies, chaotropic agents irreversibly disaggregated a majority of the aggregated protein. An integrated processing mode, termed as on-column disaggregation, was developed in which the protein was captured on Protein A chromatography and then a chaotropic agent was used to simultaneously elute the bound protein and disaggregate the HMW species. On-column disaggregation process resulted in protein recoveries of >95% and aggregation reduction of ,50%. Analytical results are presented showing that the recovered monomeric material was comparable to the reference protein in biochemical, biophysical, and pharmacokinetic properties. The kinetic and molecular mechanisms governing protein aggregation and disaggregation will also be elucidated. For the Fc-fusion protein studied here, incorporation of the disaggregation strategy in both batch and on-column modes led to an increase of >10% in overall downstream yield. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Expression of functional Candida antarctica lipase B in a cell-free protein synthesis system derived from Escherichia coliBIOTECHNOLOGY PROGRESS, Issue 2 2009Chang-Gil Park Abstract This article reports the cell-free expression of functional Lipase B from Candida antarctica (CalB) in an Escherichia coli extract. Although most of the cell-free synthesized CalB was insoluble under conventional reaction conditions, the combined use of molecular chaperones led to the soluble expression of CalB. In addition, the functional enzyme was generated by applying the optimal redox potential. When examined using p -nitrophenyl palmitate as a substrate, the specific activity of the cell-free synthesized CalB was higher than that of the reference protein produced in Pichia pastoris. These results highlight the potential of cell-free protein synthesis technology as a powerful platform for the rapid expression, screening and analysis of industrially important enzymes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] | ||||||||||