How our cells are controlled by billions of molecular ’switches’
Washington, August 4 (ANI): Chemists at UC Santa Barbara have developed a theory explaining how billions of cell-controlling molecular "switches" work in the body.
Writing about their work in the Proceedings of the National Academy of Sciences (PNAS), the researchers say that their findings may significantly help efforts to build biologically based sensors for the detection of chemicals ranging from drugs to explosives to disease markers.
Biosensors are artificial molecular switches that mimic the natural ones, which direct chemical responses throughout the cell.
"These switching molecules control the behavior of our cells. By studying these switches, we can better understand how living organisms are able to monitor their environment and use this knowledge to build better sensors to detect, for example, disease markers," said Alexis Vallee-Belisle, a postdoctoral scholar who spearheaded the project and is first author of the paper.
The researchers say that the survival of all creatures, from bacteria to humans, depends upon how they monitor their environments, which they do with biomolecular switches made from RNA or proteins.
Receptor proteins in our sinuses, which can detect different odours to warn us of danger or to tell us that food is nearby, is one example of such switches, say the researchers.
In addition to deriving the mathematical relationships underlying switching, Vallee-Belisle spent months performing a hands-on study of an artificial biomolecular switch to demonstrate that the theory holds up quantitatively.
Like a light switch, biomolecular switches often exist in two states — on or off. When a biomolecule switches from on to off, or vice versa, its shape changes.
The researchers say that this change in structure is often triggered by the physical binding of a signalling molecule-for example, the odorant molecule responsible for a given smell-to the switch.
However, unlike the single light switch that controls any one light in a house, cells use hundreds to millions of copies of each switch. Because there is more than one copy involved, the switching process is not a binary, "all-or-none" process. Instead, the output signal is determined by the fraction of switches that move from the off state to the on state.
The researchers say that they have developed a simple mathematical model that will allow biotech researchers to fine-tune the ease with which artificial biomolecular switches can be "flipped".
In their paper, the researchers also shed light on how natural biomolecular switches evolved. (ANI)