Engineering Carboxylic Acid Reductase (CAR) through a Whole-Cell Growth-Coupled NADPH Recycling Strategy

2020 ◽  
Vol 9 (7) ◽  
pp. 1632-1637
Author(s):  
Levi Kramer ◽  
Xuan Le ◽  
Marisa Rodriguez ◽  
Mark A. Wilson ◽  
Jiantao Guo ◽  
...  
2003 ◽  
Vol 8 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Siddhartha Roychoudhury ◽  
Kelly M. Makin ◽  
Tracy L. Twinem ◽  
David T. Stanton ◽  
Sandra L. Nelson ◽  
...  

A high-throughput screen (HTS)was developed and used to identify inhibitors of bacterial DNA gyrase. Among the validated hits were 53 compounds that also inhibited mammalian topoisomerase II with IC50 values of <12.5 µg/mL for 51 of them. Using computational methods, these compounds were subjected to cluster analysis to categorize them according to their chemical and structural properties. Nine compounds from different clusters were tested for their whole-cell inhibitory activity against 3 cancer cell lines—NCI-H460 (lung), MCF7 (breast), and SF-268 (CNS)—at a concentration of 100 µM. Five compounds inhibited cell growth by >50% for all 3 cell lines tested. These compounds were tested further against a panel of 53 to 57 cell lines representing leukemia, melanoma, colon, CNS, ovarian, renal, prostate, breast, and non–small cell lung cancers. In this assay, PGE-7143417 was found to be the most potent compound, which inhibited the growth of all the cell lines by 50% at a concentration range of 0.31 to 2.58 µM, with an average of 1.21 µM. An additional 17 compounds were also tested separately against a panel of 10 cell lines representing melanoma, colon, lung, mammary, ovarian, prostate, and renal cancers. In this assay, 4 compounds—PGE-3782569, PGE-7411516, PGE-2908955, and PGE-3521917—were found to have activity with concentrations for 50% cell growth inhibition in the 0.59 to 3.33, 22.5 to 59.1, 7.1 to >100, and 24.7 to >100 µM range. ( Journal of Biomolecular Screening 2003:157-163)


Author(s):  
Michael L. Simpson ◽  
Timothy E. McKnight

In chapter 5 we focused on the informational interface between cells and synthetic components of systems. This interface is concerned with facilitating and manipulating information transport and processing between and within the synthetic and whole-cell components of these hybrid systems. However, there is also a structural interface between these components that is concerned with the physical placement, entrapment, and maintenance of the cells in a manner that enables the informational interface to operate. In this chapter we focus on this structural interface. Successful integration of whole-cell matrices into microscale and nanoscale elements requires a unique environment that fosters continued cell viability while promoting, or at least not blocking, the information transport and communication pathways described in earlier chapters. A century of cell culture has provided a wealth of insight and specific protocols to maintain the viability and (typically) proliferation of virtually every type of organism that can be propagated. More recently, the demands for more efficient bioreactors, more compatible biomedical implants, and the promise of engineered tissues has driven advances in surface-modification sciences, cellular immobilization, and scaffolding that provide structure and control over cell growth, in addition to their basic metabolic requirements. In turn, hybrid biological and electronic systems have emerged, capable of transducing the often highly sensitive and specific responses of cellular matrices for biosensing in environmental, medical, and industrial applications. The demands of these systems have driven advances in cellular immobilization and encapsulation techniques, enabling improved interaction of the biological matrix with its environment while providing nutrient and respiratory requirements for prolonged viability of the living matrices. Predominantly, such devices feature a single interface between the bulk biomatrix and transducer. However, advances in lithography, micromachining, and micro-/nanoscale synthesis provide broader opportunities for interfacing whole-cell matrices with synthetic elements. Advances in engineered, patterned, or directed cell growth are now providing spatial and temporal control over cellular integration within microscale and nanoscale systems. Perhaps the best defined integration of cellular matrices with electronically active substrates has been accomplished with neuronal patterning. Topographical and physicochemical patterning of surfaces promotes the attachment and directed growth of neurites over electrically active substrates that are used to both stimulate and observe excitable cellular activity.


2020 ◽  
pp. 073168442097519
Author(s):  
Paveena Tangudom ◽  
Ignacio Martín-Fabiani ◽  
Benjaphorn Prapagdee ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
...  

The mechanical and antibacterial properties of acrylic rubber/poly(methyl methacrylate) (AR/PMMA) blend at 10 to 50 wt% of AR content with non-treated and treated titanium dioxide (TiO2) and 2-Hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate (HPQM) by N-2(aminoethyl)-3-aminopropyl trimethoxysilane were studied. The antibacterial property against Escherichia coli was evaluated. The results found that the mechanical properties of ARt-TiO2/PMMA and ARt-HPQM/PMMA blend were higher than that of the ARTiO2/PMMA and ARHPQM/PMMA blend. For antibacterial property, the ARHPQM/PMMA and ARt-HPQM/PMMA blend could act as the antibacterial material, while the ARTiO2/PMMA blend did not show. However, the ARt-TiO2/PMMA blend could inhibit bacterial cell growth with 10 to 30 wt% of AR content. The recommended compositions of ARt-TiO2/PMMA blend, which improved both mechanical and antibacterial properties, were 10 to 30 wt% of AR and were 10 to 50 wt% of AR for ARt-HPQM/PMMA. Moreover, the UV radiation increased the antibacterial properties by the destruction of the interaction in treated TiO2 and HPQM and improved the antibacterial performance of ARt-TiO2/PMMA and ARt-HPQM/PMMA blend.


2008 ◽  
Vol 35 (11) ◽  
pp. 1441-1445 ◽  
Author(s):  
C. Liberman ◽  
M. Takagi ◽  
J. Cabrera-Crespo ◽  
M. E. Sbrogio-Almeida ◽  
W. O. Dias ◽  
...  

2005 ◽  
Vol 58 (1) ◽  
pp. 14 ◽  
Author(s):  
Martin G. Banwell ◽  
Alison J. Edwards ◽  
David W. Lupton ◽  
Gregg Whited

The title compound 3, a potential building block for the construction of analogues of the clinically important anti-cancer agent vinblastine (1), has been prepared in an efficient manner through a whole-cell biotransformation of m-ethyltoluene (4) using the microorganism Pseudomonas putida BGXM1 which expresses the enzyme toluate dioxygenase (TADO). Metabolite 3 was readily converted into derivatives 5–8 using conventional chemical techniques and the structure, including absolute stereochemistry, of the last of these was established by single-crystal X-ray analysis.


Author(s):  
V. F. Allison ◽  
G. C. Fink ◽  
G. W. Cearley

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.


Author(s):  
Dean A. Handley ◽  
Jack T. Alexander ◽  
Shu Chien

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.


Author(s):  
Carol Allen

When provided with a suitable solid substrate, tissue cells undergo a rapid conversion from the spherical form expressed in suspension culture to a characteristic flattened morphology. As a result of this conversion, called cell spreading, the cell nucleus and organelles come to occupy a central region of “deep cytoplasm” which slopes steeply into a peripheral “lamellar” region less than 1 pm thick at its outer edge and generally free of cell organelles. Cell spreading is accomplished by a continuous outward repositioning of the lamellar margins. Cell translocation on the substrate results when the activity of the lamellae on one side of the cell become dominant. When this occurs, the cell is “polarized” and moves in the direction of the “leading lamellae”. Careful analysis of tissue cell locomotion by time-lapse microphotography (1) has shown that the deformational movements of the leading lamellae occur in a repeating cycle of advance and retreat in the direction of cell movement and that the rate of such deformations are positively correlated with the speed of cell movement. In the present study, the physical basis for these movements of the cell margin has been examined by comparative light microscopy of living cells with whole-mount electron microscopy of fixed cells. Ultrastructural observations were made on tissue cells grown on Formvar-coated grids, fixed with glutaraldehyde, further processed by critical-point drying, and then photographed in the High Voltage Electron Microscope. This processing and imaging system maintains the 3-dimensional organization of the whole cell, the relationship of the cell to the substrate, and affords a large sample size which facilitates quantitative analysis. Comparative analysis of film records of living cells with the whole-cell micrographs revealed that specific patterns of microfilament organization consistently accompany recognizable stages of lamellar formation and movement. The margins of spreading cells and the leading lamellae of locomoting cells showed a similar pattern of MF repositionings (Figs. 1-4). These results will be discussed in terms of a working model for the mechanics of lamellar motility which includes the following major features: (a) lamellar protrusion results when an intracellular force is exerted at a locally weak area of the cell periphery; (b) the association of cortical MFs with one another determines the local resistance to this force; (c) where MF-to-MF association is weak, the cell periphery expands and some cortical MFs are dragged passively forward; (d) contact of the expanded area with the substrate then triggers the lateral association and reorientation of these cortical MFs into MF bundles parallel to the direction of the expansion; and (e) an active interaction between these MF bundles associated with the cortex of the expanded lamellae and the cortical MFs which remained in the sub-lamellar region then pulls the latter MFs forward toward the expanded area. Thus, the advance of the cell periphery on the substrate occurs in two stages: a passive phase in which some cortical MFs are dragged outward by the force acting to expand the cell periphery, and an active phase in which additional cortical MFs are pulled forward by interaction with the first set. Subsequent interactions between peripheral microfilament bundles and filaments in the deeper cytoplasm could then transmit the advance gained by lamellar expansion to the bulk of the cytoplasm.


Sign in / Sign up

Export Citation Format

Share Document