Protein extracted soluble

Extraction and partial purification of photoprotein. The solubility and general luminescence characteristics of the S. luminosa photoprotein are similar to those reported for the S. oualaniensis photoprotein the protein is soluble in buffer solutions containing 0.6-1.0 M salt but not in solutions containing 0.1-0.2 M salt, and the luminescence is pH-dependent. In the extraction of S. oualaniensis,... 

Figure 4. Purification of PemB from E. coli K38 pGPl-2/pPME6-5 cells. Proteins were separated by urea-SDS-PAGE. Lane 1, induced cell lysate lane 2, soluble protein fraction from induced cells lane 3, membrane fraction from non-induced cells lane 4, membrane fraction from induced cells lane 5, membrane proteins not extracted by Triton X-100 lane 6, membrane proteins extracted by Triton X-100 lane 7, PemB purified by preparative electrophoresis. The molecular weight standard positions are indicated.

Fig. 1.4 Protein blot analysis of C5-1 assembly in agroinfiltrated alfalfa leaves. Total leaf soluble proteins, extracted 4 days after infiltration were separated by SDS-PAGE under non-reducing conditions and blotted onto a PVDF membrane. Polyclonal antimouse IgGs were used for detection. Purified C5-1 was mixed with total soluble proteins from control infiltrated alfalfa leaves and loaded as a standard.

Fig. 11.3 Purification ofSOl-lOOxELP-proteins from transgenic tobacco plants by inverse transition cycling and analysis by SDS-PAGE. 1 15 pg of total soluble leaf protein extracted in raw extract buffer 2 cleared supernatant of original 15 pg total soluble leaf protein after heat treatment (60 min, 95 °C) 3 cleared supernatant of original 300 pg leaf protein after heat treatment 4 cleared supernatant of original 300 pg leaf protein after heat treatment (60 min, 60 °C) with 2 M NaCI 5 redissolved spider silk-elastin protein pellet from original 300 pg of total soluble leaf protein after heat treatment (60 min, 60 °C) with 2 M NaCI.

PMR studies have been performed on a number of other ribosomal proteins isolated by the acetic acid/urea method (Morrison etal., 1977a). The results of these studies have shown that acedc acid/urea-extracted proteins contain little tertiary structure. However, some structure was seen in protein S4 and especially in protein S16 as indicated by the appearance of ring-current shifted resonances in the apolar region of the spectrum (Morrison et al., 1977b). These are due to the interaction of apolar methyl groups with aromatic amino acids in the tertiary structure of the protein. The PMR spectra were recorded either in water or in dilute phosphate buffer at pH 7.0—conditions under which the proteins were soluble. 

When the solubility assay gave an 5 value larger than 0.125, the GST-fiised protein extracted in a soluble fraction was purified on glutathione-sepharose beads. 

The abnormal deposits found in the brains of CJD victims consist of an abnormal isoform of PrP. Prion protein is normally found in cells. Detailed structural studies show that normal cellular PrP (PrP ) is a soluble protein whose conformation is rich in a-helices with very little P-sheet. The PrP protein extracted from the brains of CJD victims (i.e., PrP ) is identical in primary amino acid sequence to the normal PrP (PrP ). However, PrP has a much greater content of P-sheet conformation with little a-helical structure. Thus PrP is neurotoxic because of its three-dimensional structure. When the prion protein is predominantly in an a-helical conformation it is nontoxic when the prion protein is predominantly in a P-sheet conformation, it kills neurons. The prion protein is thus made neurotoxic not by its amino acid composition but by its conformation. This concept is both fascinating and terrifying. Prion diseases are transmissible thus prions are infectious agents. However, prions are not like bacteria or viruses, or other infectious microbes—they are simply protein molecules. Prions are not microbes with cell membranes and nucleic acids they are not living things. Indeed, prions are not even infectious molecules, they are infectious molecular shapes. 

Protamine sulphate (from herring sperm) [9007-31-2] (a]p -85.5 (satd H2O). A strongly basic protein (white powder) with pKa values of 7.4-8.0 used to ppte nucleic acids from crude protein extracts. It dissolved to the extent of 1.25% in H2O. It is freely soluble in hot H2O but separates as an oil on cooling. It has been purified by chromatography on an IRA-400 ion-exchange resin in the SO form and washed with dilute H2SO4. Eluates are freeze-dried under high vacuum below 20°. This method is used to convert proteamine and protamine hydrochloride to the sulphate. [UV Rasmussen Z physiol Chem 224 97 1934, Ando and Sawada J Biochem Tokyo 49 252 1961, Felix and Hashimoto Z physiol Chem 330 205 1963]... 

Before selecting a method to measure a specific aspect of protein functionality, one must decide on the complexity of the testing matrix. Researchers have used a single purified protein, a crude extract of proteins, a prototype food product, or an actual product to study protein functionality. For meat studies, formulated meat systems, ground muscle, myofibrillar proteins, salt-soluble proteins, actomyosin,... 

Additional application of IAP has been in the production of species-specific antibodies. Martin et al (136) first purified crude animal protein extracts by IAP. These purified proteins were then used to raise horse-specific monoclonal antibodies. This approach helped in significantly shortening the isolation time of species-specific monoclonal antibodies. A similar approach was used for pig-specific soluble muscle protein polyclonal antibodies (137). 

Determine the protein concentration of the soluble protein extracts by Bradford assay (20) to confirm that effective cell lysis has occurred see Note 5). 

When the protein is present within a cellular organelle, these methods can still be suitable. However, they may be preceded by isolation of the organelles. Sometimes, the protein has low solubility in the extraction medium, and produces a particulate system requiring specific techniques. These proteins can be extracted through thermal, chemical, or enzymatic treatments, and in some cases detergents are needed for solubilization. In any case, it is essential that a suitable solvent is selected for protein extraction. 

The use of industrial enzymes for the synthesis of bulk and fine chemicals represents a somewhat specialized application for biocatalysts relative to their broader uses, as outlined above. Industrial biocatalysis is, however, becoming increasingly relevant within the chemical industry for the production of a wide range of materials (see Table 31.3).1,2,4-8 Broadly defined, a biocatalytic process involves the acceleration of a chemical reaction by a biologically derived catalyst. In practice, the biocatalysts concerned are invariably enzymes and are used in a variety of forms. These include whole cell preparations, crude protein extracts, enzyme mixtures, and highly purified enzymes, both soluble and immobilized. 

The content of protein in soluble extracts of 1.0 M NaCl suspensions at pH 1.5 was less than that at pH 4.0. The changes in protein of insoluble preparations after each pH adjustment were the Inverse of that of the soluble extracts (Figure 5). 

The percentages of proteins in water-soluble extracts of suspensions of peanut meal adjusted from pH 6.7 to 4.0, then back to either 6.7 or 8.2, were less than those of the initial extract and the one-step pH change, respectively (Figure 5). Percentage of protein in soluble extracts at pH 6.7 or 8.2 was not altered greatly by the two-step pH adjustment. 

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