Phosphorylation is basically a chemical process in which functional group phosphate (PO3–) is added to some organic compound to form a new compound. In the fields of biochemistry it holds a great industrial value. Removing the phosphoryl group from a organic compound is called dephosphorylation. Both the processes of phosphorylation and dephosphorylation is carried out with the help of enzymes like kinases or phosphotransferases.
In medical science addition of the phosphate to glucose is called glucose monophosphate and addition of phosphate to adenosine diphosphate (ADP) forms out adenosine triphosphate (ATP).
What are the main functions of phosphorylation?
Phosphorylation and dephosphorylation does a lot of work inside the human body and outside too. Here we will gonna discuss about its significance inside of human body. Basically phosphorylation plays a crucial regulatory role for the cells. And the main functions of phosphorylation Is:
- Plays a key role in glycolysis
- Hugely important for protein-protein interaction
- Important for protein degradation
- Regulates enzymes neutralization
- Regulates several chemical reaction for maintaining homeostasis.
Like other sugar glucose is often phosphorlylated in the first step of their process of catabolism. It often happens that in the first step of glycolysis D-glucose is converted into D-glucose-6-phosphate. Glucose is a very small molecule that easily gets absorbed by the cells. And the process of phosphorylation increases the size of the glucose molecule so that it cannot be absorbed easily by the entire tissue. Phophorylation makes a wall against the glucose concentration in blood. Meanwhile glucose concentration of blood is directly related to glycogen formation which is also related to cardiac growth of the body.
Phoebus levene from the Rockefeller institute of medical research is first person who have noticed the phosphorylation of protein in 1906. But enzymatic phosphorylation of protein was not discovered till 1930s.
Protein phosphorylation happens when phosphoryl group is added to an amino acid. Most of the time amino is serine, although phosphorylation also happens in therionine and tyrosine in eukaryotes and histidine in prokaryotes. This whole process of phosphorylation is a esterification reaction where a phosphate group reacts with hydroxyl group (OH-) of the side chain of serine, tyrosine and histidine. The enzyme called protein kinase makes the covalent bond between phosphate group and amino acid. This whole process of mechanism makes the difference between prokaryotes and eukaryotes. The best studying formation of phosphorylation is post-translation modifications. After being translated from RNA proteins are phosphorylated. Dephosphorylation; which is the reverse process of phosphorylation is always catalyzed by protein phosphatases.
Phosphorylation of histone is a very important example of phosphorylation. Histone proteins systemise DNA to form out chromatin. The procedure of histone phosphorylation is the modification process of the structure of chromatin. It is needless to say that this thing modifies the DNA-protein and protein-protein interaction.
Most of the time phosphorylation comes in work when DNA is damaged, so that the repair mechanism can start their work in the opened area around the broken DNA.
It is clearly visible that it has a huge importance in DNA repair, although phosphorylation performs a lead role in signaling pathways and metabolism.
Oxidative phosphorylation explains that how a cell acquires and releases chemical energy. These chemical reactions ensue within the mitochondria of a eukaryote cell. Oxidative phosphorylation is formed up upon electron transport chain reaction. In short, when redox reaction occurs; protein passes electrons and the other molecules comprised under electron transport chain in the inner membrane of the mitochondria produces energy that forms up the molecule called adenosine triphosphate (ATP) in chemiosmosis.
In this particular process electron transport chain receive electrons from NADH and FADH2. While progressing along the chain and producing energy; electrons move from higher energy level to lower energy level. This energy now comes in contact with the pumping hydrogen ions (H+) to establish an electrochemical gradient. At the last part of the chain the electrons are shifted to oxygen and make a bond with H+ so that it can be formed as water (H2O). For synthesizing ATP; ATP synthase receives energy from the H+ ions. After the dephosphorylation of ATP, tearing the phosphate group produces energy in a particular formation that can be used in cell as a power resource.
Adenosine is not the only component that passes through phosphorylation to produce ATP, ADP and AMP. Guanosine is a another component that can make the formation of GDP, GTP and GMP.
How to Detect Phosphorylation?
What If someone appears with a question that how to detect that if a molecule is phosphorylated or not?
Well it would not be so difficult to find out that if a molecule is phosphorylated or not? Phosphorylation of a molecule can be easily detected by using mass spectrometry, electrophoresis, and antibodies. Meanwhile; identification of proper phosphorylation sites is bit difficult. Most of the time isotope labeling is used in combination with electrophoresis, immunoassays and fluorescence.
So here in this initiative i have tried to give some important information about the process of phosphorylation. if you have gone through the article already then you must understand that how important phosphorylation is for living beings as it is hugely responsible for the energy resources of the body.
I have listed out only the essential points here, which i think are the most appropriate ones. so if you like what you have read then please don’t forget to leave your valuable comment in the comments section below and also let me know if have missed out something important. i’ll try to update the post as soon as possible.