Scientists from the Scripps Research Institute (Scripps) in Florida, USA, have succeeded in turning dogs with a limited ability to "fight" certain proteins into protein killers.
"Through high-throughput screening, a method that uses robotic equipment to synthesize thousands of different substances at the same time," said Thomas Kodadek, a professor in the Department of Chemistry at the research institute Asher in Florida, who led the project. "The problem is that usually the intensity of their activity is moderate - which prevents them from being an effective research tool. By connecting this "arrowhead" isolate to the peptoid, we were able to show that it is possible to increase their protein elimination capacity by thousands of meters without requiring expensive and time-consuming optimization processes."
The innovative method provides researchers with rapid availability of highly selective and powerful radiation-activated compounds capable of inactivating certain protein functions - an important tool in the study of disease understanding and prevention. Since light can be focused with high spatial resolution, this method could open a window to inactivate proteins only in a certain part of a single cell, and not in other parts, such as inactivating a target protein in the cell nucleus and not in the surrounding cytoplasm.
The method is called CALI (chromophore-assisted light inactivation) - inactivation by light with the assistance of a chromophore; Chromophores are molecules capable of absorbing visible or ultraviolet light. Although other researchers have previously prepared this type of reactants, they suffered from low efficiency, mainly due to self-deactivation. The innovative arrowhead used by researchers at the Scripps Institute represents a significant advance in this field.
The researchers used a derivative of ruthenium, a metallic element capable of producing what is known as singlet oxygen - the active and shorter-lived form of isolated oxygen (O2). "When ruthenium absorbs visible light," explains the researcher, "it needs to get rid of this excess energy to return to its normal state. In this process, it produces a highly active form of oxygen that cleaves any protein in its environment. In fact, this strain completely destroys the protein."
Although studies of other arrowhead-bearing peptoids have been published in the past, the new study notes, the ruthenium precursor they used represents an important technical advance, one that will allow scientists to selectively target a protein found both inside and outside the cell. Unlike singlet oxygen-producing organic materials, the innovative ruthenium conjugate itself does not react to the active form, a feature that significantly increases the efficiency of the method.
The other important characteristic, the researchers point out, is that the new peptoids have no effect on the components of the cell and the body before they are activated by the light irradiation.
Simple synthetic compounds such as peptoids have many disadvantages compared to other ligands (substances that bind to proteins and change their activity), such as antibodies, the researcher notes. On the other hand, they can be easily modified so that they bind to surfaces and can be produced very quickly in huge quantities - a library of several million different peptoids in just three days. This fact makes them ideal building blocks for biomedical research, the article noted.
The researcher Kodadek became interested in developing this innovative method when he and another researcher, Benjamin Cravatt, head of the Department of Chemical Physiology, decided to merge two separate technologies - the synthesis of a library of peptoids and a method for sorting them, developed in Kodadek's laboratory, and the method of ABPP (activity-based protein profiling, detection activity-based proteins), which was developed in the laboratory of researcher Cravatt. The combination provided an innovative and powerful method for sorting and locating leading materials for the development of high quality drugs.
"However, when we just started thinking about the collaboration to identify hundreds of protein ligands at the same time, my initial enthusiasm was conditioned by the fact that I knew that the activity of these substances should only be modest and that we would not be able to use such a large number of them to improve their activity," said the researcher the main "Our innovative "arrowhead" method solved this problem."
