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51.
Ting‐Hang Liu Chia‐Lin Chyan Feng‐Yin Li Ying‐Jie Chen Jason T. C. Tzen 《Biotechnology progress》2011,27(6):1760-1767
It has been demonstrated that caleosin alone is sufficient to stabilize artificial oil bodies. A series of recombinant caleosins, mutated with 3, 5, 8, 11, 13, 15, and 17 extra Lys residues and over‐expressed in Escherichia coli, were used as carrier proteins to render biotin as a hapten on the surface of artificial oil bodies for antibody production. Biotinylation levels of the recombinant caleosins were step‐wisely elevated as the number of extra Lys residues increased, and the biotinylated Lys residues were identified by mass spectrometric analysis. Polyclonal antibodies against biotin were successfully generated in rats injected with artificial oil bodies constituted with each of the biotinylated caleosins. Moreover, those generated via the biotinylated caleosins with eight or more extra Lys residues no longer recognized caleosin. It appears that engineered Lys‐rich caleosins are suitable carrier proteins for the production of antibodies against small molecules. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 相似文献
52.
The difficulty in predicting the consequences of interactions between different cytokine networks has increased with the expansion
of the T helper (Th) cell universe and the discovery of numerous B lymphocyte-derived cytokines. Consequently, it is now difficult
to conceptualize a straightforward view of the contribution of these disturbances to the pathogenesis of primary Sj?gren's
syndrome (SS). Th1 cells, which produce interferon-γ and IL-2, and Th17 cells, which make IL-17 and TNF-α, have been cast
in the leading roles of the play. However, the complex role of T-cell subsets in SS is accentuated by the reciprocal effects
of Th17 cells and regulatory T cells found in salivary glands of SS patients. Furthermore, B lymphocyte polarization into
type-1 B effector (Be1) and Be2 cells and B-cell modulating factors of the TNF family, most notably the B-cell-activating
factor (BAFF), and their prominent role in SS are additional complicating factors. Whereas Th17 cells orchestrate autoreactive
germinal centers, local BAFF would repress the generation of Th17 cells. Such new insights into interconnected cytokines in
primary SS may lead to new treatments for these patients. 相似文献
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Bacteriochlorophyll, Fatty-Acid, and Protein Synthesis in Relation to Thylakoid Formation in Mutant Strains of Rhodospirillum rubrum 总被引:7,自引:3,他引:4 下载免费PDF全文
Mutant strains of Rhodospirillum rubrum are isolated which are blocked in different stages of pigment synthesis. In these strains the morphogenesis of thylakoids and the pigment production are investigated. Concerning bacteriochlorophyll synthesis two groups of mutants are separable. The members of the first group synthesize bacteriochlorophyll. Some of these mutants excrete bacteriopheophytin. The strains of the second group are not able to synthesize bacteriochlorophyll. Members of both groups excrete bacteriochlorophyll precursors into the cultural medium. These pigments were identified by their spectral properties as Mg-2,4-divinyl-pheoporphyrin a(5)-monomethylester, pheophorbide a, and 2-devinyl-2-hydroxyethyl-pheophorbide a. Thylakoids are only formed by those strains which are able to synthesize bacteriochlorophyll. However, small amounts of bacteriochlorophyll can be produced without a concomitant thylakoid synthesis. The fatty-acid pattern in some mutants is modified quantitatively. However, the results do not indicate any correlation between disturbance of thylakoid morphogenesis and a deviation of fatty-acid composition. Fatty acids seem to have no special functions in thylakoid morphogenesis. The membranes of the mutants were isolated, split into protein subunits, and these were separated by disc electrophoresis. A characteristic protein pattern, first of all a high content of fraction E, is correlated with the ability to form thylakoids. In addition, all mutants which synthesize bacteriochlorophyll contain a fast-migrating membrane protein (zone G). The results suggest that the whole bacteriochlorophyll-protein complex is necessary for thylakoid formation. 相似文献
58.
The characteristics of the inducible galactose transport system in bakers' yeast were studied in uridine diphosphate, galactose-1-phosphate uridylyl-transferaseless cells. Transferaseless cells transport galactose at the same initial rate as wild-type cells and accumulate a mixture of free galactose and galactose-1-phosphate. The addition of 14C-labeled galactose to cells preloaded with unlabeled galactose and galactose-1-phosphate results in a higher rate of labeling of the free-sugar pool than of the galactose-1-phosphate pool. These results support other evidence that galactose uptake in bakers' yeast is a carrier-mediated, facilitated diffusion and that phosphorylation is an intracellular event after uptake of the free sugar. 相似文献
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