Oriented immobilization of enzyme–DNA conjugates on magnetic Janus particles for constructing a multicompartment multienzyme system with high activity and stability

2020 ◽  
Vol 8 (36) ◽  
pp. 8467-8475
Author(s):  
Hao Shen ◽  
Xuelian Zheng ◽  
Zixin Zhou ◽  
Wenting He ◽  
Mengqi Li ◽  
...  
Keyword(s):  
High Activity ◽  
Tannic Acid ◽  
Janus Particles ◽  
Dna Conjugates ◽  
Multienzyme System ◽  
Oriented Immobilization

An exquisitely designed multicompartment multienzyme system has been constructed by encapsulating poly-tannic acid (pTA) on the surface of enzyme–DNA conjugates, which are anchored on magnetic Janus particles.

scholarly journals Passive Janus Particles Are Self-propelled in Active Nematics

2021 ◽  
Author(s):  
Benjamin Loewe ◽  
Tyler N Shendruk
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
High Activity ◽  
Topological Charge ◽  
Colloidal Particles ◽  
The Self ◽  
Janus Particles ◽  
Active Systems ◽  
Active Liquid ◽  
Small Activity

Abstract While active systems possess notable potential to form the foundation of new classes of autonomous materials, designing systems that can extract functional work from active surroundings has proven challenging. In this work, we extend these efforts to the realm of designed active liquid crystal/colloidal composites. We propose suspending colloidal particles with Janus anchoring conditions in an active nematic medium. These passive Janus particles become effectively self-propelled once immersed into an active nematic bath. The self-propulsion of passive Janus particles arises from the effective +1/2 topological charge their surface enforces on the surrounding active fluid. We analytically study their dynamics and the orientational dependence on the position of a companion −1/2 defect. We predict that at sufficiently small activity, the colloid and companion defect remain bound to each other, with the defect strongly orienting the colloid to propel either parallel or perpendicular to the nematic. At sufficiently high activity, we predict an unbinding of the colloid/defect pair. This work demonstrates how suspending engineered colloids in active liquid crystals may present a path to extracting activity to drive functionality.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

Cell Fine Structure as Revealed in Dessicator-Dried Resinless Sections

1981 ◽  
Vol 39 ◽  
pp. 622-623
Author(s):  
R. P. Becker ◽  
J. J. Wolosewick ◽  
J. Ross-Stanton
Keyword(s):  
Fine Structure ◽  
Tannic Acid ◽  
Three Dimensional ◽  
Albino Rats ◽  
Cell Organelles ◽  
Vascular Perfusion ◽  
Thin Sections ◽  
Carbon Coated ◽  
Embedding Medium ◽  
Polyethylene Glycol 6000

Methodology has been introduced recently which allows transmission and scanning electron microscopy of cell fine structure in semi-thin sections unencumbered by an embedding medium. Images obtained from these “resinless” sections show a three-dimensional lattice of microtrabeculfee contiguous with cytoskeletal structures and membrane-bounded cell organelles. Visualization of these structures, especially of the matiiDra-nous components, can be facilitated by employing tannic acid in the fixation step and dessicator drying, as reported here.Albino rats were fixed by vascular perfusion with 2% glutaraldehyde or 1.5% depolymerized paraformaldehyde plus 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4). Tissues were removed and minced in the fixative and stored overnight in fixative containing 4% tannic acid. The tissues were rinsed in buffer (0.2M cacodylate), exposed to 1% buffered osmium tetroxide, dehydrated in ethyl alcohol, and embedded in pure polyethylene glycol-6000 (PEG). Sections were cut on glass knives with a Sorvall MT-1 microtome and mounted onto poly-L-lysine, formvar-carbon coated grids while submerged in a solution of 95% ethanol containing 5% PEG.

Extracellular filaments in the perineurium of the florida lobster, Panulirus argus

1987 ◽  
Vol 45 ◽  
pp. 784-785
Author(s):  
Roy J. Baerwald ◽  
Lura C. Williamson
Keyword(s):  
Blood Brain Barrier ◽  
Glial Cells ◽  
Tannic Acid ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Brain Barrier ◽  
Cacodylate Buffer ◽  
Nerve Cords

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.

High-activity samarium-153-EDTMP therapy followed by autologous peripheral blood stem cell support in unresectable osteosarcoma

2001 ◽  
Vol 40 (06) ◽  
pp. 215-220 ◽  
Author(s):  
S. Bielack ◽  
S. Flege ◽  
J. Eckardt ◽  
J. Sciuk ◽  
H. Jürgens ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
High Activity ◽  
Peripheral Blood ◽  
Peripheral Blood Stem Cell ◽  
Blood Stem Cell ◽  
High Dose ◽  
External Radiotherapy ◽  
Primary Tumor Site ◽  
Hematopoietic Stem

Summary Purpose: Despite highly efficacious chemotherapy, patients with osteosarcomas still have a poor prognosis if adequate surgical control cannot be obtained. These patients may benefit from therapy with radiolabeled phosphonates. Patients and Methods: Six patients (three male, three female; seven to 41 years) with unresectable primary osteosarcoma (n = 3) or unresectable recurrent sites of osteosarcomas (n = 3) were treated with high-activity of Sm-153-EDTMP (150 MBq/kg BW). In all patients autologous peripheral blood stem cells had been collected before Sm-153-EDTMP therapy. Results: No immediate adverse reactions were observed in the patients. In one patient bone pain increased during the first 48 hrs after therapy. Three patients received pain relief. Autologous peripheral blood stem cell reinfusion was performed on day +12 to +27 in all patients to overcome potentially irreversible damage to the hematopoietic stem cells. In three patient external radiotherapy of the primary tumor site was performed after Sm-153-EDTMP therapy and in two of them polychemotherapy was continued. Thirty-six months later one of these patients is still free of progression. Two further patients are still alive. However, they have developed new metastases. The three patients who had no accompanying external radiotherapy, all died of disease progression five to 20 months after therapy. Conclusion: These preliminary results show that high-dose Sm-153-EDTMP therapy is feasible and warrants further evaluation of efficacy. The combination with external radiation and polychemotherapy seems to be most promising. Although osteosarcoma is believed to be relatively radioresistant, the total focal dose achieved may delay local progression or even achieve permanent local tumor control in patients with surgically inaccessible primary or relapsing tumors.

Gastric Fibrinolysis

1975 ◽  
Vol 34 (02) ◽  
pp. 409-418 ◽  
Author(s):  
I. M Nilsson ◽  
S.-E Bergentz ◽  
U Hedner ◽  
K Kullenberg
Keyword(s):  
Gastric Ulcer ◽  
Gastric Juice ◽  
High Activity ◽  
Fibrinolytic Activity ◽  
Duodenal Juice ◽  
Bleeding Tendency ◽  
Local Fibrinolysis ◽  
Heated Plates

SummaryGastric juice from 15 normals, 20 patients with gastric ulcer and 4 patients with erosive haemorrhagic gastroduodenitis was investigated in respect of its activity on unheated and heated fibrin plates and its content of FDP and plasminogen or plasmin with immunochemical methods. Gastric juice from normals showed no activity on unheated and heated fibrin plates, and no FDP or plasminogen could be demonstrated. In the patients with gastric ulcer the gastric juice showed little or no fibrinolytic activity on fibrin plates except in 2, who had regurgitation of duodenal juice and neutral pH of the juice. These patients had equally high activity on heated as on unheated plates and no plasmin could be demonstrated. It was shown that this activity was not due to fibrinolysis, but to non-specific proteolytic activity (probably trypsin). The patients with erosive haemorrhagic gastroduodenitis exhibited quite a different picture. The gastric juice from these patients showed extremely high activity on fibrin plates, the activity was higher on unheated than on heated plates. The activity was inhibited in vitro by addition of EACA and in vivo after administration of AMCA. The occurrence of plasmin could be demonstrated directly immunologically in the gastric juice. By comparison of plasmin and trypsin in various assays it could further be proved that the gastric juice in these cases contained plasminogen activator and plasmin. The patients with erosive haemorrhagic gastroduodenitis showed no increase in fibrinolysis in the blood, but low values for plasminogen and α2M, and the serum contained FDP. These findings in the blood and gastric juice were interpreted as signs of local fibrinolysis in the stomach and duodenum. There is reason to assume that this gastric fibrinolysis contributes substantially to the bleeding tendency. The effect of administration of AMCA on fibrinolytic activity and the haemorrhage lends support to the assumption of such a mechanism.

Use of Factor VIII in the Treatment of Hemophilia

1962 ◽  
Vol 07 (02) ◽  
pp. 230-238 ◽  
Author(s):  
A Pavlovsky ◽  
H Peterson ◽  
G Casillas ◽  
C Simonetti ◽  
A Martinez Canaveri ◽  
...  
Keyword(s):  
Factor Viii ◽  
Tannic Acid ◽  
Deae Cellulose ◽  
Fibrinolytic System ◽  
Purification Method ◽  
Fraction I

SummaryThis publication describes the results obtained by treatment of haemophiliacs with factor VIII preparations isolated from Cohn fraction I by use of tannic acid, FI-O-Ta.The authors stress the rapidity of the disappearance of factor VIII after injection. Transfusions are generally well tolerated. One reaction of the pyrogen type has been observed and also a case of activation of the fibrinolytic system.A second purification method by means of chromatography on DEAE-cellulose is described.

Separation of Heparin into Subtractions by DEAE-Cellulose Chromatography

1979 ◽  
Vol 42 (05) ◽  
pp. 1452-1459 ◽  
Author(s):  
Robert H Yue ◽  
Toby Starr ◽  
Menard M Gertler
Keyword(s):  
High Activity ◽  
Uronic Acid ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Net Charge ◽  
Uronic Acid Content ◽  
Successful Separation ◽  
Salt Gradient ◽  
Structure And Activity ◽  
Low Activity

SummaryCommercial porcine heparin can be separated into three distinct subtractions by using DEAE-cellulose chromatography and a stepped salt gradient. Gram quantities of heparin can be fractionated by this technique. All three heparin subtractions can accelerate the inhibition of thrombin by antithrombin III with different efficiency. The specific activities of the high activity heparin, intermediate activity heparin and low activity heparin are 228 units/mg, 142 units/mg and 95 units/mg, respectively. Both the uronic acid content and the quantity of N-SO4 for all three heparin subfractions have been evaluated. The high activity heparin has the lowest uronic acid and N-SO4 content. The successful separation of commercial heparin into three distinct subfractions by means of ion-exchange chromatography suggests that the net charge on these three heparin components will serve as a model system in the elucidation of the structure and activity relationship to the biological function of heparin.

Sign in / Sign up

Export Citation Format

Share Document