An international research team headed by Professor Dr. Thomas Dierks at Bielefeld University has discovered a hereditary enzyme deficiency. It is a subform of the mucopolysaccharidosis syndrome and has been termed MPS IIIE or after its discoverer 'Dierks's disorder'. It leads to a progressive loss of mental abilities in mice, particularly to learning and coordination difficulties along with forgetfulness. The biochemist Dierks and his team have not only identified the disorder but also developed a treatment concept. Their findings are being published this week (CW 24) in the renowned journal 'Proceedings of the National Academy of Sciences of the USA' (PNAS).
Enzymes control the constitution and degradation of nutrient and messenger substances in the human body. If the body produces a defective enzyme due to an inherited deficiency, this control breaks down. The individual becomes ill because, for example, substances can no longer be degraded and accumulate in the body.
Dierks and his colleagues have discovered that a deficiency of the enzyme arylsulfatase G (ARSG) triggers the disease MPS IIIE in mice. Actually, the enzyme among others - is responsible for degrading the carbohydrate heparan sulfate. This process occurs within the cells inside the lysosomes. These 'recycling plants' in the cells break down no longer needed heparan sulfate molecules into their smallest components, which later are used to reassemble new molecules.
Heparan sulfate is a long-chain molecule. This chain can only be broken down from one end and only step by step. This process is performed by various enzymes including ARSG. If one of the enzymes is deficient because of a genetic defect, the complete degradation process comes to a stop. The molecular chains remain largely intact and accumulate more and more in the lysosome, which finally stops functioning. Then, also other substances such as proteins and lipids also accumulate because they are n
|Contact: Prof. Dr. Thomas Dierks|
University of Bielefeld