When we transfer genetic material from one species to another, do we really have any conception of all the ramifications? On April 8th, 2000, Dr. Barry Commoner gave his fascinating answer in his banquet presentation at the annual forum of Beyond Pesticides.
In genetic engineering a piece of DNA (deoxyribonucleic acid) that has been found to control certain characteristics in one living species is often inserted into another living species. The double helix of DNA with its fantastically diverse possibilities for coding is made up of varying sequences of just four different nucleic acids. Normal proteins with their myriad functions in living organisms are made up of twenty different amino acids, each protein having a particular sequence and number of amino acids.
Illustrating his lecture Dr. Commoner held up a long rope with differently colored sections representing the different amino acids in a protein. Then, he used a simile from business organizations. He spoke of the DNA, (transferred from one species to another in genetic engineering) as the "top management," which then forms RNA (ribonucleic acid), the "middle management." RNA then forms the amino acid sequences of the various proteins, which are the workers and carry out our essential functions. However, Dr. Commoner pointed out that a straight, unfolded string of amino acids is essentially "dead." Then, he squeezed his colored rope to have us see visually that any protein can form into many different shapes. The number of different twists and turns possible for a single protein has been calculated as one followed by one hundred zeroes. It will take a super fast computer a year to calculate the possibilities. He emphasized that the particular places where amino acids touch make up the active sites of the protein and depending on how it has folded, we get completely different active sites. Dr. Commoner told us that the genetic engineering industry has been ignoring the folding of the proteins.
Each new protein has another protein, already in the organism, which acts as a "chaperone" to guide the new protein to fold itself into exactly the right shape from the many possibilities. Thus, a protein with exactly the same amino acid sequence as that found in the species from which the DNA was taken could have a completely different shape and function in the new species.
The genetic characteristics of individuals within a species depend on two complementary systems that have developed together over the millennia of evolution. Specifically, the characteristics of living organisms depend not only on the DNA (top management) that genetic engineering transfers from one species to another but also absolutely essentially on the specific folding of the (worker) proteins, which are shaped and then replicated by the chaperones in the receiving species. Since the genetic engineering industry has been ignoring the second system—the folding of the proteins—we have to tell them the scientific facts and have them face up to the vast uncertainties.
Dr. Commoner pointed out that introducing foreign DNA from another species can be likened to a corporate takeover into a hostile environment. Proteins would appear whose amino acid sequence is given by the inserted foreign genes. However, we really have no idea how the existing chaperone proteins would fold new proteins. We can expect unpredictable shapes with the possibility of dangerous active sites.
He gave us a scary example of a kind of protein—an infectious prion, sometimes called a slow virus, which is just a protein and has been proven to contain no nucleic acid whatsoever (no DNA nor RNA). (See NOHA NEWS, Spring 1999.) An infectious prion can have exactly the same amino acid sequence as a normal prion that is found in the brains of mammals. However, with its different shape it can cause a cascade of normal prions to imitate the viral prion shape and become in turn infectious prions themselves. Then, the infected animals (including human beings) gradually die of an incurable and always fatal encephalitis (inflammation of the brain).
Genetic engineering may very well be helpful in medical research, where the resulting organisms are quite carefully controlled. However, in agriculture and food production, genetic engineering has been introduced wholesale with no control of drift and without knowledge of the amazing and possibly disastrous ramifications of the introduction of foreign DNA into unrelated living species, where we can picture an almost infinite number of new protein shapes with new active sites and consequences. For our food, we need to follow the European example and demand labeling, rather than the present inundation of our markets with unlabelled genetically engineered food.
Article from NOHA NEWS, Vol. XXV, No. 3, Summer 2000, page 5.