fun with jolecule:The Antibody

The protein that I will be exploring in this article is the antibody. I find the antibody interesting because of the high amount of variability in terms of different antibodies that all seek to perform similar functions like neutralizing toxins or viruses.These toxins or viruses are called antigens..  Even with the high amount of variability in antibodies all antibodies share parts of their

Structure .Antibodies are proteins produced in vertebrates ( by b cells) mostly made up of beta pleated sheets with a small number of alpha helices which you can see in the general overview of the antibody above. They are also covered in short chains of carbohydrates called glycoproteins (which I have also shown above). Antibodies are made up of two light chains and two heavy chains of proteins. These chains make a “Y” shape(to the left the the intertwined heavy chains are circled in blue and the light chains are in red). The tips of the “Y” have a region that is of high variability among different antibodies. This means in different antibodies in the tips of the Y the primary structure varies. This is because the tips contain the areas that bind to antigens called antigen binding sites.This also explains the reason why antibodies need to have a high amount of variability in the primary structure of the tips.There are a wide amount of things the body would consider an antigen that an antibody would need to bind to and if the structure of every antibody was exactly the same it would not be able to complete that function.

Above three binding sites are circled in red These three sites are rearranged in different antibodies to achieve the effect of binding to a specific antigen.These sites are called paratopes and they bind to epitopes on antigens. The primary structure of the paratope causes the site to fold in a way that will allow the site to bond to the epitope.  By binding to an antigen an antibody can change the structure and therefore the function of a part of an invading virus, for example, and render it unable to invade the cell.