ABSTRACT
High-molar-mass hyaluronan (HA) – glycosaminoglycan composed of repeating disaccharide units of N-acetyl-d-glucosamine and d-glucuronic acid linked by β-(1→4) and β-(1→3) glycoside bonds – is an essential component of the extracellular matrix in many tissues. It is rather susceptible to free-radical mediated degradation resulting in various physiological and pathological consequences. In the present study, we investigated the effect of N-(2-mercapto-2-methylpropionyl)-l-cysteine against free-radical degradation of highmolar-mass HA. We applied rotational viscometry to record time-dependent changes of the dynamic viscosity of HA solutions, which reflected a decrease of HA molar-mass and thereby its fragmentation. The oxidative degradation of high-molar-mass hyaluronan was evoked by the Weissberger biogenic oxidative system comprising Cu(II) and ascorbate. Previously, we proved that stage I of oxidative HA degradation was mediated predominantly by hydroxyl radicals while stage II by peroxyl-type radicals. To determine the scavenging activity of the compound tested, ABTS and DPPH assays were used. Oximetry was used to monitor the consumption of oxygen by the treated HA solutions.
