To understand recombinant proteins and how they are synthesized, first it is important to have some background information on DNA. DNA is the code that determines the genetic information of a living being. It actually determines the protein of the body, which is one of the most important components of life. There are four bases to a DNA code, which are Thymine (T), Cytosine, Guanine (G) and Adenine (A), and how these bases could be arranged is infinite. They are coded in the double helix structure, with a sugar phosphate as the backbone, and hydrogen bonds found in between the bases.
Recombinant proteins refer to the process of combining a piece of DNA with another piece derived from another organism. Through this technology, a new sequence of DNA strand – or in other words, a new recombinant expression - is synthesized. Do know that recombinant protein synthesis refers to recombinant protein production.
There are many methods for synthesizing recombinant protein, and these are the following: transformation (both bacterial and non-bacterial) and phage introduction (or transfection). Solubility is a factor in the success of synthesizing recombinant protein.
The process of transformation can make use of recombinant bacteria – such as E. coli – in order to transport the piece of DNA into the target destination. The bacteria are plasmids and are referred to as a vector, and in simplest terms, this vector is exposed to an antibiotic marker, so that it will not be destroyed by antibiotics (other bacteria which have not been exposed to the antibiotic marker will be destroyed by the antibiotic, as usual). Non-bacterial transformation, as the name implies the process does not use bacteria (because the use of bacteria as vector may actually pose some risks specially for people who are suffering from a disease the compromises their immune system). To replace the vector, vaccines are used – that is, the recombinant DNA is injected right into the destination cell. Phage introduction, or transfection, makes use of phages (or packaging such as MI3) in place of bacteria.
Once the recombinant genes are introduced to the target cell, this host cell will then produce similar recombinant protein – this is called protein expression. This is where expression factors come in. The host cell must receive instructions in the form of signals regarding gene transcription and gene translation. The vector must contain these signals, and include the promotor, the binding site, and the terminator.
The synthesis of recombinant proteins is very significant, especially if its application is in the area of human recombinant proteins. Recombinant insulin, vaccines and pharmaceuticals are continuously being developed to combat such diseases such as diabetes, hepatitis B, sickle cell anemia and cystic fibrosis. Apart from its applications in the search for cures for common diseases, recombinant protein synthesis is also studied for the improvement of crops – that is, to make crops and plants more resistant to disease, insects, pests and drought.
Apart from recombinant protein synthesis, other similar topics include gene subtraction and addition, DNA replication, gene splicing, and gene therapy.