Definition: In biomedicine, the term labile means short-lived or susceptable to change, and is usually used in reference to the destruction of proteins. The term is also often used to describe the shelf-life of drugs that are sensitive to light, heat, moisture or other environmental conditions. In protein research, labile is used to describe the post-translation lifespan of proteins within the cell. Labile proteins are those that are easily destroyed by heat, pH or other environmental factors. Proteins are also destroyed by other biomolecules within the cell, in particular proteasomes which consist of ribosomes and other proteins. The initiation of protein degradation depends upon cell signalling processes, like ubiquitination, that recognize old or improperly formed proteins.
Examples:The labile protein had a short half-life of only 2 hours before it was destroyed by ribosomes.