Recovery of proteins

The largest industrial use of ultrafiltration is the recovery of paint from water-soluble coat bases (primers) applied by the wet electrodeposition process (electrocoating) in auto and appliance factories. Many installations of this type are operating around the world. The recovery of proteins in cheese whey (a waste from cheese processing) for dairy applications is the second largest application, where a... 

The ionic species of the mobile phase will also affect the separation. This is shown in Table 4.3 by the difference in resolution values for magnesium chloride buffer compared to sodium sulfate buffer. In addition, calibration curves for proteins in potassium phosphate buffers are shallower than those generated in sodium phosphate buffers. The slope of the curve in Sorenson buffer (containing both Na and ) is midway between the slopes generated with either cation alone (1). Table 4.4 illustrates the impact of different buffer conditions on mass recovery for six sample proteins. In this case, the mass recovery of proteins (1,4) is higher with sodium or potassium phosphate buffers (pH 6.9) than with Tris-HCl buffers (pH 7.8). 

TABLE 4.4 Effect of Buffer Composition on Mass Recovery of Proteins from TSK-GEL G3000SW< ... 

Poor recovery of biological activity with good recovery of protein... 

Adsorption in expanded or fluidised beds is now widely adopted for the direct recovery of protein products from particulate feedstocks. As an integrative protein recovery operation it circumvents process bottlenecks encountered with the solid liquid separation required upstream of fixed bed adsorption, while achieving considerable concentration and primary... 

Recently, an enzymatic method was reported to recover the three main components of industrial shrimp waste (protein, chitin, and astaxanthin) using treatments with alcalase and pancreatin. The first enzyme was more efficient in increasing the recovery of protein from 57.5 to 64.6% and of astaxanthin from 4.7 to 5.7 mg/lOO g of dry waste. 

Chen, L.A., Carbonell, R.G., and Serad, G.A., Recovery of proteins and other biological compounds using fibrous materials I adsorption by salt addition, /. Chem. Technol. Biotechnol., 74, 733, 1999. 

The suppression and recovery of protein synthesis from DTT treatment (without cycloheximide treatment) can be monitored via metabolic pulse radiolabeling of cell cultures using [35S]-methionine and subsequent determination of radiolabeled protein content either by SDS-PAGE/ phosphor-imager analysis or liquid scintillation of tricholoroacetic acid insoluble material (Stephens et al., 2005). 

TABLE 14.2 Effects of Detergent and pH on the Recovery of Protein from FFPE Lysozyme Tissue Surrogates... 

TABLE 19.2 Recovery of Protein from a Lysozyme Tissue Surrogate... 

A decrease of the total recovery of proteins from tempera layers has been correlated with the presence of inorganic cations [11 16] that may reduce the solubility of the organic materials due to cross-linking reactions where cations may be active as catalysers. 

Stop the reaction by removing the solution from the beads. This can be done by simply pipetting the solution away from the beads or by physically removing the beads. The beads may be washed once with iodination buffer to assure complete recovery of protein. Exact timing of the reaction is important to obtain reproducible results. 

Shimkus, M., Levy, J., and Herman, T. (1985) A chemically cleavable biotinylated nucleotide Usefulness in the recovery of protein-DNA complexes from avidin affinity columns. Proc. Natl. Acad. Sci. USA 82, 2593-2597. 

Marti, C., Roeckel, M., Aspe, E., Kanda, H., Recovery of proteins from fishmeal wastewaters, Process Biochem., 29, 1994, 39. 

The cut point of 15 microns on the Alpine air classifier gave an fineicoarse split of 31.8 61.7 for field pea but the yield of protein fraction was much higher at 37.0% for fababean (Table II). Based on the protein contents of the fine fractions (Table I), the recoveries of protein in the fine fraction were 75.5% for field pea and 80.0%... 

On the basis of proteinate yields (Table II) and their protein contents (Table I), the recoveries of protein during wet processing were about 73% for both legumes, which was only slightly below the efficiency of the dry process. However, the losses of starch in the whey and wash solids were substantial, and starch recoveries averaged 77.5%. The yields of refined fiber were about 8% of the raw materials. Almost 30% of the dry matter from wet processing would have to be recovered from whey and wash extracts to make the process economical. 

Polymers and resins Water purification, including removal of phenol, chlorophenols, ketones, alcohols, aromatics, aniline, indene, polynuclear aromatics, nitro- and chlor-aromatics, PCB, pesticides, antibiotics, detergents, emulsifiers, wetting agents, kraftmill effluents, dyestuffs recovery and purification of steroids, amino acids and polypeptides separation of fatty adds from water and toluene separation of aromatics from ahphatics separation of hydroquinone from monomers recovery of proteins and enzymes removal of colours from symps ... 

The formation of two aqueous phases can be exploited in the recovery of proteins using liquid-liquid extraction techniques. Many factors contribute to the distribution of a protein between the two phases. Smaller solutes, such as amino acids, partition almost equally between the two phases, whereas larger proteins are more unevenly distributed. This effect becomes more pronounced as protein size increases. Increasing the polymer molecular weight in one phase decreases partitioning of the protein to that phase. The variation in surface properties between different proteins can be exploited to improve selectivity and yield. The use of more hydrophobic polymer systems, such as fatty acid esters of PEG added to the PEG phase, favors the distribution of more hydrophobic proteins to this phase. In Fig. 10.13, partition coefficients for several proteins in a dextran-PEG system are given [27]. 

This paper will focus on the use of statistically designed experiments to develop effective purification processes in the most time and cost efficient fashion. Downstream processing and the recovery of proteins by severd different techniques have been discussed in other articles (1-3) and will not be discussed here. 

Recovery of proteins from ultrafiltration depends not only on the size, but also on the solute composition and the type of membrane, since unspecific adsorption of the protein to the membrane cannot be excluded. Furthermore, the chemical resistance of the membrane to buffer components and sanitation ingredients should be taken into consideration. 

Native RNase is quite resistant to digestion with trypsin, even at a w/w ratio of 1 20, but small or unfolded fragments would be expected to be digested. When the synthetic enzyme was treated with trypsin, a 70% recovery of protein with a specific activity of 61% was obtained. Treatment of this material with saturated ammonium sulfate (diluted 16 26), pH 4.6, gave 33% of amorphous precipitate and 66% of soluble RNase A. The overall yield from the first Val residue was only 3%, but the specific activity was quite high at 78%. This is as far as the purification was carried out at that time. 

RME shows particular promise in the recovery of proteins/enzymes [12-14]. In the past two decades, the potential of RME in the separation of biological macromolecules has been demonstrated [15-20]. RMs have also been used as media for hosting enzymatic reactions [21-23]. Martinek et al. [24] were the first to demonstrate the catalytic activity of a-chymotrypsin in RMs of bis (2-ethyl-hexyl) sodium sulfosuccinate (Aerosol-OT or AOT) in octane. Since then, many enzymes have been solubilized and studied for their activity in RMs. Other important applications of RME include tertiary oil recovery [25], extraction of metals from raw ores [26], and in drug delivery [27]. Application of RMs/mi-croemulsions/surfactant emulsions were recognized as a simple and highly effective method for enzyme immobilization for carrying out several enzymatic transformations [28-31]. Recently, Scheper and coworkers have provided a detailed account on the emulsion immobiUzed enzymes in an exhaustive review [32]. 

AOT/isooctane/ buffer Horse liver alcohol dehydrogenase Microemulsion system that is temperature sensitive to phase separate was used for recovery of proteins and enzymes [283]... 

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