Since the deciphering of the human genome, much of research on it has been transferred to the study of the proteome, the proteins made from the genetic "blueprints" stored in our cells. After all, proteins carry out most of the work in the body and understanding how they behave should help researchers figure out how to treat most illnesses. However, cells not only consist of genes and proteins, but also of carbohydrates (sugars) and lipids (fats). Carbohydrates, which were once regarded as energy-yielding molecules, are now known to combine with the cell surfaces and influence cell-to-cell communication, the immune system, the ability of various agents to make us sick, and the progression of cancer. .
Even at the simplest level, a better understanding and control of sugars improves existing therapies. Enhanced control of sugars improves the effectiveness of proteins made by recombinant DNA. To work effectively, certain proteins must have particular sugars attached to them. This is seen in the recombinant drug erythropoietin, which is used to stimulate red blood cell production. For years companies discarded about 80 percent of the erythropoietin they made because of inadequate glycosylation, which results in the drug being removed from the blood too quickly. In time, a way was found to add two extra sugars to erythropoietin. This newer version of the drug stayed in the blood longer than the original and therefore required less frequent dosing.
Today many researchers work with infectious diseases, an arena in which sugar-related drugs have already had some success. An example of this is the vaccine for Hemophilus influenzae type b. This vaccine has freed much of the world from the sometimes-deadly meningitis caused by the virus. By presenting a sugar from Hemophilus influenzae type b to the immune system, the vaccine primes the system to destroy the virus once it enters the body. These highly effective glycoconjugate preparations, in which the sugar is joined to a protein that boosts immune responsiveness, have been available since the late 1980s.
