Hannes Koeppel

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OBJECTIVE The (CTG)(n) polymorphism in the serum carnosinase (CN-1) gene affects CN-1 secretion. Since CN-1 is heavily glycosylated and glycosylation might influence protein secretion as well, we tested the role of N-glycosylation for CN-1 secretion and enzyme activity. We also tested whether CN-1 secretion is changed under hyperglycemic conditions. (More)
Activity of carnosinase (CN1), the only dipeptidase with substrate specificity for carnosine or homocarnosine, varies greatly between individuals but increases clearly and significantly with age. Surprisingly, the lower CN1 activity in children is not reflected by differences in CN1 protein concentrations. CN1 is present in different allosteric(More)
In humans, we reported an association of a certain allele of carnosinase gene with reduced carnosinase activity and absence of nephropathy in diabetic patients. CN1 degrades histidine dipeptides such as carnosine and anserine. Further, we and others showed that treatment with carnosine improves renal function and wound healing in diabetic mice and rats. We(More)
Serum carnosinase (CN-1) measurements are at present mainly performed by assessing enzyme activity. This method is time-consuming, not well suited for large series of samples and can be discordant to measurements of CN-1 protein concentrations. To overcome these limitations, we developed sandwich ELISA assays using different anti-CN-1 antibodies, i.e.,(More)
BACKGROUND Heparin and angiotensin-converting enzyme inhibitors can be used as a therapeutic option in diabetic nephropathy (DN). Although the mode of action is poorly understood, both agents may retard the progression of DN. Previously, we demonstrated that angiotensin II (Ang II) has an inhibitory effect on the production of heparan sulphate proteoglycan(More)
A considerable variability in the incidence and prevalence of diabetic nephropathy (DN) coheres with an important contribution of multigenetic predisposition in the development of DN. Some genes, which probably participate in the pathogenesis of diabetic nephropathy, also play a role in the regulation of blood pressure, familial hyperlipidemia, familial(More)
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