London: Scientists have figured out how humans and other organisms avoid poisoning by carbon monoxide produced within the body.
Carbon monoxide (CO), a colourless, odorless and tasteles gas, found in car fumes or seeping from faulty heating systems, is referred to as `the silent killer`.
In our bodies, CO is also produced through normal cellular activity, the journal Proceedings of the National Academy of Science reports.
Researchers from the universities of Manchester, Liverpool and Eastern Oregon have now identified the mechanism that protects cells from CO`s toxic effects at lower concentrations.
CO molecules should be able to readily bind with protein molecules found in blood cells, known as haemproteins, according to a Manchester statement.
Then they would impair normal cellular functions, such as oxygen transportation, cell signalling and energy conversion, causing fatal effects.
The haemproteins fit CO molecules, much like a hand fitting a glove, so that its natural production, even at low concentrations, should bind to the haemproteins and poison the organism, except it does not.
"Our work identifies a mechanism by which haemproteins are protected from carbon monoxide poisoning at low concentrations of the gas," said Nigel Scrutton, professor based at the Manchester Interdisciplinary Biocentre, who led the study.
When the haemprotein `senses` the toxic gas output within the cell, it modifies its structure, not permitting CO molecules to bind to it.
Derren Heyes, Scrutton`s co-author, said: "Without this structural change, carbon monoxide would bind to the haemoprotein almost a million times more tightly, which would prevent the natural cellular function of the haemprotein."