A failed experiment with excellent results: species-specific enzymatic inactivation

Abstract

This article describes a failed experiment carried out in 1992, which marks the beginning of a collaboration of more than 20 years of the author with Dr. Armando Gómez Puyou.  This experiment demonstrates how experimental research can generate information even though the objectives for which the experiments are designed are not achieved. A particular case of what is known as serendipity. The text first gives a brief description of the chemistry of protein iodination with the chloramine-T reagent. Subsequently, the use of the “Penefsky column” is described, which allows large molecules (such as proteins) to be quickly separated from small molecules (such as the chemical reagents used in the iodination reaction). The experiment failed because the radioactive iodine did not bind to the rabbit triosephosphate isomerase protein in the presence of chloramine –T. However, as a consequence of this experiment, Dr. Armando Gómez Puyou noticed that chloramine-T strongly inactivated the enzymatic function of triosephosphate isomerase from rabbits but practically did not affect the enzymatic function of triosephosphate isomerase from yeast. From this observation a new project emerged: the study of the species-specific enzymatic inactivation of triosephosphate isomerase, a key enzyme in glycolysis.