| 1. |
- Franco, Telma Teixeira, et al.
(författare)
-
Single-step partitioning in aqueous two-phase systems
- 2000
-
Ingår i: Aqueous Two-Phase Systems – Methods and Protocols. - New Jersey : Humana Press. - 9780896035416 - 9781617370670 - 9781592590285 ; , s. 47-54
-
Bokkapitel (refereegranskat)abstract
- Partitioning in aqueous two-phase system (ATPS) provides a rapid and gentle means of separation of soluble as well as particulate biomaterials, e.g. proteins, nucleic acids, cells, viruses, organelles, and membranes. Partitioning between the two phases is a complex phenomenon, guided mainly by the interaction of the partitioned substance and the phase components, e.g., through hydrogen bonds, van der Waals-, hydrophobic-, and electrostatic- interactions, steric-, and conformational effects, etc.
|
|
| 2. |
- Hatti-Kaul, Rajni, et al.
(författare)
-
Aqueous two-phase systems : A general overview
- 2000
-
Ingår i: Aqueous Two-Phase Systems : Methods and Protocols - Methods and Protocols. - New Jersey : Humana Press. - 9780896035416 - 9781617370670 - 9781592590285 ; , s. 1-10
-
Bokkapitel (refereegranskat)abstract
- Phase separation in solutions containing polymer mixtures is a very common phenomenon; in fact, miscibility of the polymer mixtures is an exception. Most hydrophilic polymer pairs are incompatible in aqueous solutions yielding two coexisting phases in equilibrium with each other, with each of the phases containing predominantly water and one of the polymer types. It is worth noting that the association of unlike polymer species into a polymer-rich phase coexisting with a polymer-poor phase, referred to as complex coacervation can also occur. However, it is the former type of phase systems that form the subject of this book.
|
|
| 3. |
- Hatti-Kaul, Rajni, et al.
(författare)
-
Extractive bioconversion in aqueous two-phase systems
- 2000
-
Ingår i: Aqueous Two-Phase Systems : Methods and Protocols - Methods and Protocols. - New Jersey : Humana Press. - 9780896035416 - 9781617370670 - 9781592590285 ; , s. 411-417
-
Bokkapitel (refereegranskat)abstract
- Biotechnological processes are characterized, in general, by low productivity and dilute product streams.
|
|
| 4. |
- Kamihira, Masamichi, et al.
(författare)
-
Integration of extraction with affinity precipitation
- 2000
-
Ingår i: Aqueous Two-Phase Systems : Methods and Protocols - Methods and Protocols. - New Jersey : Humana Press. - 9780896035416 - 9781617370670 - 9781592590285 ; , s. 371-379
-
Bokkapitel (refereegranskat)abstract
- Conventional aqueous two-phase extraction by spontaneous partitioning has often problems with low specificity. The introduction of an affinity ligand into one of the phases has been attempted to enhance the specificity of protein partitioning (1-7; Chapters 29-31). However, this procedure still has some limitations in the effective removal of impurities as well as recovery and reuse of the ligand. During the past decade, another potentially scalable technique, affinity precipitation, has been studied for the isolation of proteins (8-10). The affinity ligand coupled to a reversibly soluble-insoluble polymer is used to specifically bind the protein in a complex mixture. The precipitation step which can be accomplished by a change in any environmental parameter such as pH, temperature, salinity, and so forth, facilitates the separation of the bound ligand and affinity complex from the unbound components. Although cells and cell debris should be removed before use, recovery and reuse of the ligand are relatively easy.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Bakhtiar, Shahrzad, et al.
(författare)
-
Crystallization and preliminary X-ray analysis of an alkaline serine protease from Nesterenkonia sp. Acta
- 2003
-
Ingår i: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047. ; 59:3, s. 529-531
-
Tidskriftsartikel (refereegranskat)abstract
- A novel calcium-independent serine protease from an alkaliphilic bacterium, Nesterenkonia sp. AL20, has been purified and crystallized at 296 K using sodium formate as the main precipitant. This enzyme is optimally active at pH 10, exhibits high stability towards autolytic digestion and its stability is not affected by the presence of EDTA or detergents. The triangular prism-shaped crystals diffracted X-rays to beyond 1.5 Å at a synchrotron beamline, with space group R3 and unit-cell parameters a = b = 92.26, c = 137.88 Å. A complete data set has been collected to 1.39 Å resolution. The asymmetric unit is estimated and confirmed by self-rotation function calculation to contain two molecules, giving a crystal volume per protein mass (VM) of 2.68 Å3 Da-1 and a solvent content of 54%.
|
|
| 9. |
- Bakhtiar, Shahrzad, et al.
(författare)
-
Stability characteristics of a calcium-independent alkaline protease from Nesterenkonia sp.
- 2003
-
Ingår i: Enzyme and Microbial Technology. - 0141-0229. ; 32:5, s. 525-531
-
Tidskriftsartikel (refereegranskat)abstract
- Thermodynamic stability of an alkaline protease from a new alkaliphilic Nesterenkonia sp. AL-20, was investigated and compared with that of Subtilisin Carlsberg. The amount of calcium bound to the AL-20 protease was determined to be only about 0.14 mol/mol of protease. Differential scanning calorimetry scan of the enzyme at increasing temperature showed the denaturation of the enzyme to be a two-state process with melting temperature, Tm of about 74 °C at pH 10.0, which was unaltered upon addition of calcium as well as after treatment with chelating agents. The thermodynamic parameters were nearly the same over a pH range of 7.0–10.0. Tm was reduced to 69.7 °C at pH 6.0 and 72 °C at pH 11.0. The secondary structure of the protease was unaffected during storage at 50 °C, even in the presence of 1% SDS as observed by circular dichroism. The protease activity was extremely stable in the presence of hydrogen peroxide and various sequestering agents used in detergents.
|
|
| 10. |
|
|
