Division of Biological Chemistry
Head: Klaus Scheffzek

Tryptophan degradation is still in focus of our experimental and clinical studies. In an intense collaboration with the NCI/Bethesda, the role of IDO and its relationship to regulatory T-cells and dendritic cells in the development of immunodeficiency in states of chronic immune activation. The influence of tryptophan degradation on the course of neuropsychiatric symptoms is investigated in patients with HIV infection (e.g. in collaboration with UCSF) and with cancer. To further characterize the role of immune activation and inflammation in cardiovascular diseases, the relationship between metabolism of homocysteine and asymmetric dimethylarginine (ADMA, 4) is investigated in vitro and in vivo. For investigating a potential influence of immune activation and oxidative stress on the metabolism of phenylalanine, a new HPLC method is to be developed and clinical collaboration studies are under way. The relationship between tryptophan metabolism and allergy development is investigated in patients and in vitro. Special attention is given to antioxidant compounds like vitamins, cannabinoids and food preservatives and experimental studies are devoted to the influence of these compounds on activated peripheral blood mononuclear cells in vitro.

In the animal models investigated in collaboration with the General and Transplantation Surgery group, we intend to optimize treatment conditions of tetrahydrobiopterin in attenuating ischemia reperfusion injury with the aim to develop a novel therapeutic strategy also applicable in humans.

In our biochemical work, we focus on the molecular characterization of alkylglycerol monooxygenase (glyceryl-ether monooxygenase), an enzyme that may contribute to metabolic actions of tetrahydrobiopterin, the sequence of which had been unknown. We have developed a 5 orders of magnitude more sensitive assay for this enzyme, assigned a sequence to this activity and aim at characterising the physiological significance of this protein. Related with this project, we study the metabolic fate of long chain fatty aldehydes using a novel, fluorescence labelled compound.