Enzymes are proteins which accelerate the chemical reaction in the cell. A special portion of the enzyme which is called "active side" is formed in such a way as to fit with the specific substrate molecules.
 
The enzyme works by binding to one or more specific molecules called "substrate".
 
Connection occurs on the active side. The enzyme and substrate form a complex enzyme substraten.
 
The interaction between the enzyme and the substrate either increases or decreases any of the chemical bonds in the substrate.
 
As a result of the chemical interactions in the active part, to form a new product.
 
He then released from the active start of the enzyme acquires its normal shape and is ready to work again.

The mitochondrial electrochemical gradient is often disturbed during apoptosis and can be detected using cationic dyes such as DePsipher™ (5,5’6,6’- tetrachloro-1,1’,3,3’-tetraethylbenz-imidazolylcarbocyanine iodide) or MitoShift™ (tetramethylrhodamine ethyl ester).

Activation of caspases, or cysteinyl proteases, is a necessary event for execution of the apoptotic response.  Some of the caspases are activated early in the apoptotic process and their activation is the first step in a cascade of proteolytic cleavage of key proteins and enzymes, including other caspases and poly (ADP-ribose) polymerase (PARP). Since the substrate specificity of the caspases is high, analysis of  substrate cleavage also provides a useful biochemical marker.

The movement of some members of the Bcl-2 family from the cytoplasm to the mitochondria and the subsequent associations that occur between them and other mitochondrial membrane associated proteins are indicated to be crucial steps in apoptosis.

DNA fragmentation occurs as one of the final stages of cell death and has long been considered a hallmark of apoptosis and one of the defining biochemical events of the pathway. For detection of the DNA fragmentation associated with apoptosis by DNA laddering, the DNA  is isolated and the cleaved fragments are separated by agarose gel electrophoresis. Our Ethidium Bromide DNA Laddering kit provides the necessary reagents for detection of the DNA ladder. 

Utilizing a TUNEL-based assay, a series of kits for the in situ detection of apoptosis with colorimetric and fluorometric options was developed. The TACS® kits are tailored for the detection of DNA fragmentation associated with apoptosis in a variety of cell and tissue types and for analysis by different formats that include microscopy, flow cytometry, and 96 well plates.

Products: anti-cleaved caspase-3, anti-PARP, PARP Apoptosis Assay Kits, Bcl-2 family antibodies, DePsipher™, MitoShift™, PBR Protein, anti-PBR  

Anti-γH2AX antibody, Apoptotic DNA laddering kit, TACS•XL®, TACS® 2TdT,  VasoTACS™, FlowTACS™, TiterTACS™ 96 Well Kit, NeuroTACS™ II, TumorTACS™, CardioTACS™, DermaTACS™ 

FEATURES

USE - Measure PGE2 between 1,000 - 31.25 pg/mL
SAMPLE - Lysates, Saliva, Urine, Serum, Plasma and Tissue
SAMPLES/KIT - 40 or 232 in Duplicate
SENSITIVE - Measure < 3 pg per Sample
VERSATILE - Works directly with Mouse and Rat Serum

DESCRIPTION

The DetectX® Prostaglandin E2 (PGE2) Immunoassay kits are designed to quantitatively measure PGE2 present in serum, plasma, urine, saliva and tissue culture media samples. Standards or diluted samples are pipetted into an antibody coated microtiter plate. A PGE2-peroxidase conjugate is added to the wells and the binding reaction is initiated by the addition of a monoclonal antibody to PGE2. After a 2 hour incubation the plate is washed and substrate is added. The substrate reacts with the bound PGE2-peroxidase conjugate. After a 30 minute incubation, the reaction is stopped and the plate read at 450nm.
Prostaglandins are synthesized from arachidonic acid by cyclooxygenase (COX)-1 or -2, which convert the acid into PGH2. This is further processed by cytosolic or microsomal prostaglandin synthases to become PGE2 or one of several other prostanoids. Prostacyclin is the major cyclooxygenase product in blood vessel walls and it is present in inflammatory fluids in similar concentrations to PGE2. PGE2 is a potent vasodilator and produces hyperalgesia. PGE2 is produced by a wide variety of tissues and in several pathological conditions, including inflammation, arthritis, fever, tissue injury, endometriosis, and a variety of cancers.

In a series of lab experiments designed to unravel the workings of a key enzyme widely considered a possible trigger of rheumatoid arthritis, researchers at Johns Hopkins have found that in the most severe cases of the disease, the immune system makes a unique subset of antibodies that have a disease-promoting role.

Reporting in the journal Science Translational Medicine online May 22, the Johns Hopkins team describes how it found the novel antibodies to peptidylarginine deiminase 4, or PAD4, in blood samples from people with aggressive inflammation and connective tissue damage.

Researchers say the presence of so-called PAD3/PAD4 cross-reactive autoantibodies could serve as the basis for the first antibody-specific diagnostic test to distinguish those with severe rheumatoid arthritis from those with less aggressive forms of the disease.
"Identifying early on a subset of patients with severe rheumatoid arthritis could benefit their health, as these patients could start aggressive drug therapy immediately and find the most effective treatment option," says senior study investigator Antony Rosen, M.D. Rosen, director of rheumatology and the Mary Betty Stevens Professor at the Johns Hopkins University School of Medicine, says that a third, or 1 million of the more than 3 million Americans -- mostly women -- estimated to have rheumatoid arthritis have an aggressive form of the disease.
In the study, the antibodies were present -- in 18 percent of 44 fluid samples from one research collection and in 12 percent of another collection of 194 -- but only in people with severe cases of rheumatoid arthritis. Past research shows that those with the most aggressive disease are less likely to respond to anti-inflammatory treatments with steroids and other drugs.
An examination of patients' medical records revealed that 80 percent of patients with the antibody saw their disease worsen over the previous year, while only 53 percent without the antibody showed disease progression. In comparing average scores of disease-damaged joints, researchers found that those with the antibody had an average deterioration in joints and bones by a score of 49. Those without the antibody had an average degradation in their score of 7.5, indicating much milder disease.
In a related finding, the Johns Hopkins team also uncovered how the PAD3/PAD4 cross-reactive auto-antibodies might contribute to more severe, erosive disease in rheumatoid arthritis. The team performed a series of experiments to gauge the antibodies' effects on PAD4 in response to varying cell levels of calcium, on which PAD enzymes depend.
Lab experiments showed that the antibodies greatly increase PAD4 enzyme function at the low levels of calcium normally present in human cells. Results showed that PAD4 activity was 500 times greater in the presence of antibodies than when they were absent. Tests of the antibody and enzymes' chemical structures later showed that the antibodies bind to PAD4 in the same region as calcium, suggesting to researchers that the antibodies might be substituting for calcium in activating the enzyme.
According to Rosen, the series of experiments, which took two years to complete, represents the first evidence of an antibody having a direct role in generating the targets of the immune response, or auto-antigens, in rheumatoid arthritis.
"Our results suggest that drugs inhibiting the PAD4 enzyme may have real benefit in patients with severe rheumatoid arthritis and represent an important field of study for investigating new and alternative treatments," says lead study investigator and biologist Erika Darrah, Ph.D.
Darrah says the team next plans long-term monitoring of arthritis sufferers to find out when the antibody first appears in the blood, and when intervention may have maximum impact in preventing or stalling disease progression. The team also plans further experiments to see if the antibody is taking control of the chemical pathways normally used by other cell proteins to control PAD4 sensitivity to calcium.
Funding support for this study was provided by the National Institutes of Health, and corresponding grant number T32-AR048522; the American College of Rheumatology; the Donald B. and Dorothy L. Stabler Foundation; and Sibley Memorial Hospital.
In addition to Rosen and Darrah, other Johns Hopkins researchers involved in this study were Jon Giles, M.D.; Michelle Ols, Ph.D.; and Felipe Andrade, M.D., Ph.D. Additional research assistance was provided by enzymologist Herbert Bull, Ph.D.

Studies of "drug" are still in a very early stage and tests are performed only on mice.

Soon fans will be able to cup sober just one pill. Researchers made ​​a cocktail of alcohol metabolizing enzymes rapidly reduce the level of alcohol in the blood while drunk mouse forward "Daily Mail". 

"Treatment", which compares with having millions of liver cells in your stomach, you may have a lasting impact on fans of spirits. Yangfeng Lou - professor of chemistry and biomolecular engineering, and Cheng Zhi - Professor of Biochemistry and Molecular Biology at the University of Southern California, injected mice with drunk nanocapsule containing two enzymes. One of the enzymes - oxidase comes as a by-product of hydrogen peroxide, which can be harmful. That's why he has to work with another enzyme to break down hydrogen peroxide. The study shows that drunken mice that were injected with these nanocapsule, sobered much faster than those who did not receive enzyme "treatment". The breakthrough is still in a very early stage and can not speak for its application in humans.

But expert Lou argues that experience can lead to the invention of a new drug to act as an antidote to alcohol. He states that "drug" can be taken as a simple pill. "It's like you have millions of liver cells in your stomach that help you revise alcohol," said Professor Lu.