Saturday, March 7, 2009

Art of Designing of Proteins


Protein design is important because it not only allows us to systematically investigate the forces that determine structure and stability but it also affords the possibility of creating proteins through novel and useful activities. The biotechnological industry is more interested in developing new types of enzymes, which are stable and more active under extreme working conditions such as high temperature and extreme pH such as acidic or alkaline pH.

Biochemists can now use a refinement of the genetic modification technique to redesign proteins. Once they have isolated the gene for a particular protein they can alter its code so that a change occurs in the protein's primary structure. They then incorporate the modified gene into a microorganism where it is decoded as before, but this time a new protein appears. Swapping one a-amino add in a protein can have a large effect on how the protein behaves. Biochemists have already used this protein engineering to modify human insulin in a way that makes it become absorbed more quickly after injection. Multiple changes are needed to 'humanize' antibodies.

Computer-modeling techniques allow protein chemists to make predictions about how proposed a-amino acid changes might change the structure and activity of a protein. Genetic and protein modification have enormous potential. Besides insulin, genetic modification can produce human growth hormone and the blood clotting factor VIII. Genetic engineering, thus, has provided a tool to produce designer proteins having special characteristics by changing the amino acid sequence. In addition, it is already possible to introduce into a plant new genes that enable it to produce its own protein insecticide or that make it resistant to disease. Hepatitis B vaccine, oil-digesting bacteria, and bacteria that produce biodegradable plastic are all recently developed products of protein engineering and genetic-modification techniques.

Creation of Novel Proteins: Vaccines are traditionally prepared from heat-inactivated microbes-bacteria or viruses or the surface proteins of these organisms to immunize against various infectious diseases. But in some cases it was frequently observed that some parts or components of the vaccines were creating some deleterious effects on people. It is known that proteins are the main candidates responsible for imparting the stimulus for immunity. Therefore, efforts have been made to design an altered protein molecule, which can produce only very little deleterious effects. There are some amino acid sequences, which are directly involved in the stimulation of immunity and that part of the protein or polypeptide is known as epitopes. A recombinant vaccine can be designed by involving only the essential epitopes in the immune response. Such vaccines will be very simple and will be safe without reducing their effectiveness. Safe vaccines against the hepatitis B virus and anthrax bacteria are under development.

Tags: Bio Technology, Bio Genetics ,Protein Designing

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