scholarly journals Direct purification of CRISPR/Cas ribonucleoprotein from E. coli in a single step

2018 ◽  
Author(s):  
Siyu Lin ◽  
Jie Qiao ◽  
Lixin Ma ◽  
Yi Liu

AbstractCRISPR/Cas ribonucleoprotein (RNP) complexes have been recently used as promising biological tools with plenty of applications, however, there are by far no efficient methods to prepare them at large scale and low cost. Here, we present a simple method to directly produce and purify Cas RNP, including the widely used Cas9 and Cas12a nuclease, from E.coli in a single step using an ultra-high-affinity CL7/Im7 purification system. The prepared Cas RNP shows high stability, solid nuclease activity in vitro, and profound genome editing efficiency in vivo. Our method is convenient, cost-effective, and applicable to prepare other CRISPR associated nucleases.

Author(s):  
Ashish Patel ◽  
Ravi Vanecha ◽  
Jay Patel ◽  
Divy Patel ◽  
Umang Shah ◽  
...  

: Cancer is a frightful disease that still poses a 'nightmare' worldwide, causing millions of casualties annually due to one of the human race's most significant healthcare challenges that requires a pragmatic treatment strategy. However, plants and plant-derived products revolutionize the field as they are quick, cleaner, eco-friendly, low-cost, effective, and less toxic than conventional treatment methods. Plants are repositories for new chemical entities and have a promising cancer research path, supplying 60% of the anticancer agents currently used. Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery and development. However, some alkaloids derived from natural herbs display anti-proliferation and antimetastatic activity on different forms of cancer, both in vitro and in vivo. Alkaloids have also been widely formulated as anticancer medications, such as camptothecin and vinblastine. Still, more research and clinical trials are required before final recommendations can be made on specific alkaloids. This review focuses on the naturally-derived bioactive alkaloids with prospective anticancer properties based on the information in the literature.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
S. Shashank Chetty ◽  
S. Praneetha ◽  
Sandeep Basu ◽  
Chetana Sachidanandan ◽  
A. Vadivel Murugan

Abstract Near-infrared (NIR) luminescent CuInS2-ZnS alloyed nanocrystals (CIZS-NCs) for highly fluorescence bioimaging have received considerable interest in recent years. Owing, they became a desirable alternative to heavy-metal based-NCs and organic dyes with unique optical properties and low-toxicity for bioimaging and optoelectronic applications. In the present study, bright and robust CIZS-NCs have been synthesized within 5 min, as-high-as 230 °C without requiring any inert-gas atmosphere via microwave-solvothermal (MW-ST) method. Subsequently, the in vitro and in vivo nano-xenotoxicity and cellular uptake of the MUA-functionalized CIZS-NCs were investigated in L929, Vero, MCF7 cell lines and zebrafish-embryos. We observed minimal toxicity and acute teratogenic consequences upto 62.5 μg/ml of the CIZS-NCs in zebrafish-embryos. We also observed spontaneous uptake of the MUA-functionalized CIZS-NCs by 3 dpf older zebrafish-embryos that are evident through bright red fluorescence-emission at a low concentration of 7.8 μg/mL. Hence, we propose that the rapid, low-cost, large-scale “sustainable” MW-ST synthesis of CIZS-NCs, is an ideal bio-nanoprobe with good temporal and spatial resolution for rapid labeling, long-term in vivo tracking and intravital-fluorescence-bioimaging (IVBI).


2018 ◽  
Author(s):  
Wenqiang Li ◽  
Shuntang Li ◽  
Jie Qiao ◽  
Fei Wang ◽  
Yang Liu ◽  
...  

AbstractCRISPR-Cas9 is a versatile and powerful genome engineering tool. Recently, Cas9 ribonucleoprotein (RNP) complexes have been used as promising biological tools with plenty of in vivo and in vitro applications, but there are by far no efficient methods to produce Cas9 RNP at large scale and low cost. Here, we describe a simple and effective approach for direct preparation of Cas9 RNP from E. coli by co-expressing Cas9 and target specific single guided RNAs. The purified RNP showed in vivo genome editing ability, as well as in vitro endonuclease activity that combines with an unexpected superior stability to enable routine uses in molecular cloning instead of restriction enzymes. We further develop a RNP-based PCR-free method termed Cas-Brick in a one-step or cyclic way for seamless assembly of multiple DNA fragments with high fidelity up to 99%. Altogether, our findings provide a general strategy to prepare Cas9 RNP and supply a convenient and cost-effective DNA assembly method as an invaluable addition to synthetic biological toolboxes.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Mi-Hye Hwang ◽  
Jung Eun Kim ◽  
Sang-Yeob Kim ◽  
Senthilkumar Kalimuthu ◽  
Shin Young Jeong ◽  
...  

The aim of the present study is to establish a bacterial clone capable of secreting an integrinαvβ3 targeting probe with bioluminescent and fluorescent activities, and to verify its specific targeting and optical activities using molecular imaging. A bacterial vector expressing a fusion of secretory Gaussia luciferase (sGluc), mCherry, and RGD (sGluc-mCherry-RGDX3; GCR), and a control vector expressing a fusion of secretoryGaussia luciferaseand mCherry (sGluc-mCherry; GC) were constructed. The GCR and GC proteins were expressed inE. coliand secreted into the growth medium, which showed an approximately 10-fold higher luciferase activity than the bacterial lysate. Successful purification of GCR and GC was achieved using the 6X His-tag method. The GCR protein bound with higher affinity to U87MG cells than CHO cells in confocal microscopy and IVIS imaging, and also showed a high affinity for integrinαvβ3 expressing tumor xenografts in anin vivoanimal model. AnE. coliclone was established to secrete an integrinαvβ3 targeting imaging probe with bioluminescent and fluorescent activities. The probe was produced feasibly and at low cost, and has shown to be useful for the assessment of angiogenesisin vitroandin vivo.


1996 ◽  
Vol 59 (6) ◽  
pp. 631-641 ◽  
Author(s):  
ANTONIO-JAVIER RAMOS ◽  
JOHANA FINK-GREMMELS ◽  
ENRIQUE HERNÁNDEZ

Mycotoxins comprise a family of fungal toxins, many of which have been implicated as chemical progenitors of toxicity in man and animals. The most thoroughly studied are the aflatoxins. A variety of physical, chemical, and biological methods to counteract the mycotoxin problem have been reported, but large-scale, practical, and cost-effective methods for detoxifying mycotoxin-containing feedstuffs are currently not available. The most recent approach to the problem has been the addition to the animal's diet of nonnutritive sorbents that sequester mycotoxins and reduce their gastrointestinal absorption, avoiding their toxic effects on livestock and toxin carryover into animal products. This review comments on the in vitro efficacy of several of the adsorbents assayed, and their in vivo applications in a range of animals will be discussed. The sorbents reviewed are activated charcoal, bentonite, zeolite, hydrated sodium calcium aluminosilicate (HSCAS) and a wide variety of clays and synthetic ion-exchange resins.


2020 ◽  
Author(s):  
Shuai Li ◽  
Huifang Zhao ◽  
Xiaobo Han ◽  
Lang He ◽  
Omar Mukama ◽  
...  

Abstract BackgroundNeural stem cells(NSCs)therapy remains one of the most potential approaches for neurological disorders treatment. The discovery of human induced pluripotent stem cells (hiPSCs) and the establishment of hiPSC-derived human neural stem cells (hiNSCs) have revolutionized our technique to cell therapy. Meanwhile, it is often required that NSCs are stored and transported long distances for research or treatment. Although high survival rates could be maintained, conventional methods of cell transport (dry ice or liquid nitrogen) are inconvenient and expensive. Therefore,the establishment of a safe, affordable, and frequent obtained hiPSCs and hiNSCs, with characteristics that match fetal hNSCs and a simple, low-cost way to store and transport, are incredibly urgent. MethodsWe reprogrammed human urinary cells to iPSCs using a virus-free technique and differentiated the iPSCs toward iNSCs/neurospheres and neurons, under Good Manufacturing Practice (GMP)-compatible conditions. The pluripotency of iPSCs and iNSCs was characterized by a series of classical methods (surface markers, karyotype analysis and in vitro and in vivo differentiation capabilities, etc).ResultsHere, our results showed that we successfully generated hiNSCs/neurospheres from more available, non-invasive, and more acceptable urinary cells by a virus-free technique and their differentiation into neural networks. Moreover,hiNSCs survived longer as neurospheres at ambient temperature than those cultured in a monolayer. Approximately 7 days, the neural viability remained at > 80%, while hiNSCs cultured in a monolayer died almost immediately. Neurospheres exposed to ambient temperature that were placed under standard culture conditions (37 ℃, 5% CO2) recovered their typical morphology, and retained their ability to proliferate and differentiate. ConclusionsIn this study, we provided a simple method for the storage of NSCs as neurospheres at ambient temperature as an alternative to more costly and inconvenient traditional methods of cryopreservation. This will enable hiNSCs to be transported over long distances at ambient temperature and facilitate the therapeutic application of NSCs as neurospheres without any further treatment.


2019 ◽  
Vol 70 (11) ◽  
pp. 4060-4067
Author(s):  
Adriana Corina Hangan ◽  
Laura Gratiela Vicas ◽  
Roxana Liana Stan ◽  
Emoke Pall ◽  
Luminita Simona Oprean ◽  
...  

Despite the fact that a large number of chemotherapeutic anticancer agents have been discovered, cancer still remains a great cause of deaths worldwide. The purpose of our researches is to discover a new antitumor drug. In this aim, two new Cu(II) complexes, [Cu(L)2(py)2(H2O)2](C1) and [Cu(L)2(phen)](C2) with a new ligand, N-(5-trifluoromethyl-[1,3,4]-thiadiazole-2-yl)-benzensulfonamide(HL) were synthesized. The complexes were characterized by elemental analysis, spectral and magnetic determinations. The nuclease activity studies of the complexes confirm their capacity to cleavage the DNA molecule. Both complexes have in vitro antioxidant activity (DPPH, FRAP methods), in vitro (using xanthine /xanthine oxidase system) and in vivo (using S.cerevisiae)SOD mimetic activity.The results of MTT assay on two carcinoma cell lines (HeLa and WM35) indicate that both complexes have antitumor activity, but (C2) has a superior activity compared with (C1) and with Cisplatin. On normal fibroblast (HDFa), (C1) showed toxicity comparable with Cisplatin, but (C2) showed a lower one. Bacterial assays were also performed (by the disk diffusion method) and both complexes have antibacterial activity against S. aureus, E. coli, P. aeroginosa and B. cereus. All the biological studies are in concordance and show that both complexes have biologic activity but (C2)is much more active.


2016 ◽  
Vol 60 (7) ◽  
pp. 4283-4289 ◽  
Author(s):  
Bo Ma ◽  
Chao Niu ◽  
Ying Zhou ◽  
Xiaoyan Xue ◽  
Jingru Meng ◽  
...  

ABSTRACTThanatin (THA) displays potent antibiotic activity, especially against extended-spectrum-β-lactamase (ESBL)-producingEscherichia colibothin vitroandin vivo, with minimal hemolytic toxicity and satisfactory stability in plasma. However, the high cost of thanatin significantly limits its development and clinical application. To reduce the cost of peptide synthesis, a formulation of cyclic thanatin (C-thanatin) called linear thanatin (L-thanatin) was synthesized and its activity was evaluatedin vivoandin vitro. Results showed that C-thanatin and L-thanatin MICs did not differ against eight Gram-negative and two Gram-positive bacterial strains. Furthermore, the survival rates of ESBL-producing-E. coli-infected mice were consistent after C-thanatin or L-thanatin treatment at 5 or 10 mg/kg of body weight. Neither C-thanatin nor L-thanatin showed toxicity for human red blood cells (hRBCs) and human umbilical vein endothelial cells (HUVECs) at a concentration as high as 256 μg/ml. Results of circular dichroism spectroscopy indicated that the secondary structure of L-thanatin is extremely similar to that of C-thanatin. Membrane permeabilization and depolarization assays showed that C-thanatin and L-thanatin have similar abilities to permeabilize the outer and inner membranes and to induce membrane depolarization in ESBL-producingE. coli. However, neither of them caused significant HUVEC membrane permeability. These findings indicate that the two peptides have similar effects on bacterial cell membranes and that the disulfide bond in thanatin is not essential for its antimicrobial activitiesin vivoandin vitro. L-thanatin is thus a promising low-cost peptide candidate for treating ESBL-producingE. coliinfections.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3778
Author(s):  
Jiping Zhao ◽  
Ganqiao Ran ◽  
Mengmeng Xu ◽  
Xiaoyun Lu ◽  
Dan Tan

3,4-dihydroxyphenyl-L-alanine (L-DOPA) is a preferred drug for Parkinson’s disease, with an increasing demand worldwide that mainly relies on costly and environmentally problematic chemical synthesis. Yet, biological L-DOPA production is unfeasible at the industrial scale due to its low L-DOPA yield and high production cost. In this study, low-cost Halomonas bluephagenesis TD01 was engineered to produce tyrosinase TyrVs-immobilized polyhydroxyalkanoate (PHA) nanogranules in vivo, with the improved PHA content and increased immobilization efficiency of TyrVs accounting for 6.85% on the surface of PHA. A higher L-DOPA-forming monophenolase activity of 518.87 U/g PHA granules and an L-DOPA concentration of 974.36 mg/L in 3 h catalysis were achieved, compared to those of E. coli. Together with the result of L-DOPA production directly by cell lysates containing PHA-TyrVs nanogranules, our study demonstrated the robust and cost-effective production of L-DOPA by H. bluephagenesis, further contributing to its low-cost industrial production based on next-generation industrial biotechnology (NGIB).


2018 ◽  
Author(s):  
Belen Gutierrez ◽  
Jérôme Wong Ng ◽  
Lun Cui ◽  
Christophe Becavin ◽  
David Bikard

AbstractThe main outcome of efficient CRISPR-Cas9 cleavage in the chromosome of bacteria is cell death. This can be conveniently used to eliminate specific genotypes from a mixed population of bacteria, which can be achieved both in vitro, e.g. to select mutants, or in vivo as an antimicrobial strategy. The efficiency with which Cas9 kills bacteria has been observed to be quite variable depending on the specific target sequence, but little is known about the sequence determinants and mechanisms involved. Here we performed a genome-wide screen of Cas9 cleavage in the chromosome of E. coli to determine the efficiency with which each guide RNA kills the cell. Surprisingly we observed a large-scale pattern where guides targeting some regions of the chromosome are more rapidly depleted than others. Unexpectedly, this pattern arises from the influence of degrading specific chromosomal regions on the copy number of the plasmid carrying the guide RNA library. After taking this effect into account, it is possible to train a neural network to predict Cas9 efficiency based on the target sequence. We show that our model learns different features than previous models trained on Eukaryotic CRISPR-Cas9 knockout libraries. Our results highlight the need for specific models to design efficient CRISPR-Cas9 tools in bacteria.


Sign in / Sign up

Export Citation Format

Share Document