Antibodies Know Right From Left

Antibodies fight disease-causing intruders, such as viruses, by binding with the intruders' molecules and thus neutralizing them. In a study reported in the April 8 issue of the Journal of the American Chemical Society, the scientists found that in seeking out appropriate molecules with which to bind, the antibodies distinguish between left- and right-handed amino acids, the building blocks of proteins. Thus, some antibodies only bind with left-handed amino acids, completely ignoring the right-handed ones, while others only bind with right-handed amino acids.

The antibodies are so exquisitely precise they can recognize a small part of a single amino acid, known as the chiral center, which determines the amino acid's orientation to the right or left. Molecules that are identical in chemical composition but whose structures are mirror images of one another, like the right and left hand, are called chiral (from chir, Ancient Greek for "hand"). Such molecules have different properties and are not superimposable.

This research may prove of great significance for the pharmaceutical industry. It has been shown in the past few years that in many drugs it is only the compound of a particular "handedness" that is effective, while its "mirror image" is useless or even harmful. Therefore, developing an efficient way to identify and sort out left- and right-handed molecules with the help of antibodies could pave the way for more effective pharmaceuticals.

Prof. Wilchek serves as Dean of the Biochemistry Faculty and holds the Marc R. Gutwirth Chair of Molecular Biology. He conducted the study with Oliver Hofstetter (recipient of a short-term fellowship from Boehringer Ingelheim Funds) and Dr. Heike Hofstetter of Weizmann's Biological Chemistry Department, Prof. Volke Schurig of Germany's Tuebingen University and Prof. Bernard S. Green of the Hebrew University of Jerusalem. Funding was provided by the German-Israeli Foundation for Scientific Research and Development (GIF).

The Weizmann Institute of Science, in Rehovot, Israel, is one of the world's foremost centers of scientific research and graduate study. Its 2,400 scientists, students, technicians, and engineers pursue basic research in the quest for knowledge and the enhancement of the human condition. New ways of fighting disease and hunger, protecting the environment, and harnessing alternative sources of energy are high priorities.