Fluorescent protein helps to conduct the study of arrhythmia

Stem cell-derived cell models play an increasingly important role in cardiac dysfunction studies. Researchers at Technical University of Munich (TUM) have successfully produced cells which are helpful to the studies of cardiac cell characteristics. Using glowing molecular sensors and recombinant human proteins will not only make the electrical activity of the cells visible, but also makes it possible to quickly identify the type of cell for the first time.

In the past decade, it has been possible to produce so-called induced pluripotent stem cells in the laboratory. These stem cells are derived from white blood cells - for example - they can be infinitely replicated in the laboratory and turn into all possible cell types. For example, heart cells generated in this way can be used to investigate arrhythmia. The can be used in animal experiments in the application and can't easily remove samples of tissue from the patient's heart. However, the cultured heart cells provide an opportunity to study such diseases in an approach of "microcosm".

"Our study addresses several problems using this type of cell model", said Dr. Daniel Sinnecker of Heart disease at Technical University of Munich. Heart cells produced in laboratory still have the problem of how to best measure the electrical activity. In the past, microelectrode is the most commonly to be used to directly determine the electrical signal of cells. However, this process is quite complicated and can only be used on a small number of cells.

The article published by Daniel Sinnecker and his team in the journal the heart of Europe offers a possible solution for the problem. Unlike making cell attaching microelectrode and other methods, the scientists used a biosensor. These are derived from fluorescence, i.e. Luminous - deep-sea jellyfish protein. Introduce DNA containing these sensor proteins "construction plans" into heart cells and then the protein of the sensor is produced. If giving labeled heart cells with a specific wavelength of light stimulation, they will produce light at different wavelengths. The returned exact color of the light depends on the voltage difference between the inside and outside of cells. Therefore, scientists can use a special camera to measure and record action potentials of single cells.

A special feature of this new approach is that the inserted DNA can be coupled with specific recognition sequences which are so-called promoters. These sensors ensured that the presence of protein production is only in a specific type of heart muscle cells. So it can capture the electrical signals from cells of atrium, ventricles and atrionector. Flarebio offers recombinant proteins of good quality such as recombinant Ext2 at competitive prices.

NRG1 protein can help to effectively treat Alzheimer's disease

According to news from RIA Novosti on August 25th, US neuroscientists made use of recombinant human proteins and found an upgraded brain protein - neuregulin 1 (NRG1) and this protein can effectively help to treat Alzheimer's disease.

It is generally throught that Alzheimer's disease is due to too much amyloid pathogenic substance called β-amyloid protein depositing inside neuron. Such β-amyloid protein is formed from β-amyloid precursor protein (APP) proteolysis. It is involved in repairing damaged proteins and can be combined with protein molecules. β-amyloid protein can lead to the emergence of amyloid plaques and death of nerve cells.

While scientists from the United States Institute of Biology Khajuraho Cambiasso Turk have recently discovered a protein having a clear function - neuregulin-1. The protein can’t only clear the protein plaques in the brain but also can slow down the formation of β - amyloid plaques.

Scientists conducted experients with mice suffering from Alzheimer's disease. They put a special virus containing neuregulin-1 proteins in brain of the lab mice. The purpose is to make the neuregulin-1 genes grow in mice. During the process of experiment, the scientists made the mice to look for exit, and then they observed whether neuregulin-1 proteins would improve the memory capacity of mice and make the protein plaques in their neurons decrease. Experiments show that the neuregulin-1 protein does improve the memory capacity of mice and remove β- amyloid protein plaques.

Currently, scientists still don't know the specific reasons for this phenomenon. But they believe that neuregulin-1 protein can promote to form another peptide - enkephalinase enzyme which can solubilize protein agglomerate. However, whether the fact is true remains to be verified through the results of recent experiments.

Besides, scientists also said that the main advantages of neuregulin protein is that it can move freely through the barrier between the brain and the rest of the body, thus it can be flexibly used to treat Alzheimer's disease. Flarebio offers recombinant proteins of good quality such as recombinant EXT2.

Why does Gleevec only bind to Abl but not recognize its kin Src?

In the journal Science, Biochemistry Professor Dorothee Kern at Brandeis University, who is also a researcher at Howard Hughes Medical Institute reveals the evolution tour of billions of years of Abl and Src protein and points out the exact evolutionary change which causes the condition that Gleevec binds well with one and binds poorly with the other. Such a new method for enzyme study and their binding sites are likely to have a significant impact on the development of rational anti-cancer drugs. According to the research using recombinant mouse proteins, the researchers knew that the two proteins have only a difference of 146 amino acids, but there is a huge difference between them - i.e. Abl is sensitive to anticancer drug Gleevec, while Src is not.

Developing more drugs like Gleevec which can play a role - referred to as rational drug design - may be possible to create some new therapies targeted to specific enzymes in many cancer types. Unfortunately, scientists don't know why Gleevec is so picky that it only binds to Abl but not recognize its kin Src.

In order to unlock this puzzle, Kern and her team made use of recombinant proteins like recombinant rat proteins and recombinant human proteins and started to find out the common ancestor of Abl and Src a billion years - an original protein which is known as ANC-AS in yeast. They draw a phylogenetic tree and searched for some amino acid changes and molecular mechanisms.

With the ANC-AS evolution in more complex organisms, it began to specialize and branch into a number of proteins which showed different control, roles and catalytic processes - generated Abl and Src. By tracking this process and testing the protein's affinity for Gleevec along this road, Kern and the study group narrowed the reasons which lead to specificity of Gleevec from the differences of 146 amino acids to that of 15 amino acids.

These 15 amino acids play a role in the conformational equilibrium of Abl. Conformational equilibrium refers to the conversion of a protein between two structures. For binding to Gleevec, the main difference between Abl and Src lies in the relative time of protein staying in each conformation, resulting in the great difference in their binding ability. By understanding the causes and mechanism of Gleveec acting on Abl and being ineffective on Src, the researchers obtained a starting point to design other drugs that have high affinity, specificity and can bind to them. Flarebio provides recombinant proteins such as recombinant Ext2 at good prices.

The mystery of Zika virus replication in the host cell has been uncovered

The mystery of Zika virus replication in the host cell has been uncovered. Recently, Yang Haitao research team from Tianjin University published an article in the journal Protein & Cell which also published some other studies on recombinant proteins (including recombinant dog proteins) to show the crystal structure of Zika virus helicase, unlocking the key process and mechanism of Zika virus replication. The results would play a positive role in the development of antiviral drugs.

In the study, Yang Haitao team successfully obtained the 3D image when Zika virus helicase was conducting function and binding to substrate. The researchers also showed the spatial structure of ternary complex formed by Zika virus helicase, adenosine triphosphate and metal catalyst ions at the atomic resolution level. In addition, they also successfully captured the intermediate state of Zika virus helicase binding to ATP and metal ions. This is the first time to reveal the structure when flavivirus family (a mosquito-borne virus, including Zika virus, dengue virus, yellow fever virus, West Nile virus, etc.) helicase binding to natural substrate ATP. Yang Haitao said, "Through the analysis of this structure, we can reveal the mechanism of how Zika virus helicase identifying ATP catalytic metal ions."

To explore the differences between Zika virus with other flavivirus members in the mechanism of replication, the researchers also resolved three-dimensional structure of complex when Zika virus helicase binding to genomic RNA. They found that a pathway across helicase was responsible for "seizing" RNA. Surprisingly, Zika virus helicase would undergo significant conformational changes after binding to RNA, while these kind of conformational changes were quite different to the helicase of dengue virus.

The study indicates that helicase of flavivirus family evolved a conservative molecular "motor" in the evolutionary process. It can turn chemical energy into mechanical energy through nucleoside triphosphate hydrolysis to implement "melting" in the process of viral replication; while making use of different "movement" mode, helicase of different virus members recognize and bind to genomic RNA in a different way to meet the needs of viral replication. Flarebio offers good-quality recombinant proteins such as recombinant EXT2 at competitive prices.