In molecular biology, the term molten globule (MG) refers to protein states that are more or less compact (hence the "globule"), but are lacking the specific tight packing of amino acid residues which creates the solid state-like tertiary structure of completely folded proteins (hence the "molten").
Although often considered a statistical random coil, the denatured state can retain residual structure that mediates (re)folding.
[4] For instance, staphylococcal nuclease retains native-like topology in 8M urea,[5] while nonnative lysozyme contains hydrophobic clusters held together by long-range interactions.
[6] By rapidly adjusting experimental conditions to favor native structure formation, relatively compact protein folding intermediates have been observed.
It was found, for example, in cytochrome c, which conserves a native-like secondary structure content but without the tightly packed protein interior, under low pH and high salt concentration.
The MG structure is believed to lack the close packing of amino acid side chains that characterize the native state (