Growing old too soon
Enzymes are involved in ageing
Enzymes that are inactive, or not active enough, are among many contributors to human ageing. Progeria is a very rare exaggerated form of ageing. It is seen in children with inadequate supplies of lamin, a fibrous protein that is vital for maintaining the structure of the cell nucleus. Patients typically suffer hair loss, joint problems and heart disease, and usually die in their mid-teens.
A major cause of progeria is a defect in a protease that completes the production of lamin from its precursor, prolamin. The protease, ZMPSTE24, is a complex transmembrane protein.
In 2013 a team of X-ray crystallographers solved its 3D structure, explaining how several mutations disable the enzyme and bring on the symptoms of one type of progeria. Understanding more about this unusual protein structure may eventually help in the development of treatment for progeria and also explain the more gradual deterioration seen in normal ageing.Lead image:
Structural Genomics Consortium