On The Track of New Wonder Drugs
The human body…It has amazing powers to fight disease of injury. Sometimes it needs a little help in the form of drugs, but today it seems that even the most powerful drugs of the future will come from the body itself – they will be derived from proteins.
On the Track of New Wonder Drugs
By Mr Ghaz, January 2, 2010
On the Track of New Wonder Drugs
The biggest helper that doctors have in curing illness in the human body is – the human body. It has amazing powers to fight disease of injury. Sometimes it needs a little help in the form of drugs, but today it seems that even the most powerful drugs of the future will come from the body itself – they will be derived from proteins.
Among their many components, proteins contain enzymes – themselves a type of protein – which help speed up chemical reactions in the body; antibodies, which help fight infections; and most hormones, which act as chemical messengers. Of approximately 25,000 proteins in the human body, scientists have been able to identify fewer than 2 percent. But of that 2 percent, a group known as peptides, or peptide hormones, has far-reaching medical significance.
Links in the Chain
Proteins are formed from amino acids, which are made up chiefly of carbon, hydrogen, nitrogen, and oxygen. As far as we now know, some 20 aminoacids are joined together by peptide bonds. The peptides are the links in the chain.
Many peptides are secreted by glands: by the thalamus, hypothalamus, and pituitary in the brain; and by the pancreas, which is located near the stomach. It is not known exactly what peptides do nor how they can be so specific in their operation.
One theory holds that they work on the jigsaw principle each peptide is made in such a way that it will fit only into one particular receptor, a protein or a hormone, for example. It “searches” for the right receptor. Once the connection has been made, it starts a series of chemical reactions, activating enzymes that in turn send “messages” to the cells to produce specialized proteins according to the needs of the body.
Some peptide drugs have been in use for many years. Among them are insulin, used in treating diabetes; somatotrophin, the growth hormone; and oxytocin, which starts milk production in mothers. Peptide drugs have already been approved for use with some forms of dwarfism, infertility, and the premature onset of puberty. Other peptides being tested may be used for treatment of cancer, depression, insomnia, and acquired immune deficiency syndrome (AIDS).
In due course scientists hope to have peptide drugs for conditions that at present are impossible to treat, such as Alzheimer’s disease. Future research will explore drugs for birth control and as replacement for antibiotics.
Improving on Nature
Until recently it was not possible to extract sufficient quantities of human peptides to use as drugs. But in the 1970’s chemists perfected a way to build up artificial peptides by bonding the first amino acid of a peptide chain to tiny resin beads. Unwanted amino acids were washed away, and a second amino acid was then bonded onto the first. This was repeated until the entire chain was created. The whole process, if computerized, can safely make drugs in the required commercial quantities in a matter of days.
Not only can chemists reproduce a natural peptide, they can also vary the sequence of the amino acids in order to make small but important changes. In this way they can give the artificial peptide certain characteristics, such as long lasting action, that the natural version does not have.
Finally, because the new drugs are so powerful, the doses can be much smaller. And since they work the same way as the body’s own peptides, they cause fewer undesirable side effects.
