Effect of bioactive aldehydes on gelatin properties

Bioactive aldehydes are among main factors of proteins postsynthetic modifications, which are the cause and consequence of many diseases. Comparative study of some aldehydes modifying action on gelatin was carried out in vitro. Gelatin samples (20 mM) were incubated with: ribose, deoxyribose, glyoxal, methylglyoxal, formaldehyde, acrolein (20 mM each) and their combinations in 0.1 M Na-phosphate buffer (pH 7.4) containing 0.02% sodium azide at 37 °C in the dark for 30 days. We investigated the fluorescent properties of these samples and their molecular weight distribution by electrophoresis. It has been revealed that formed adducts had different fluorescence spectra. According to fluorescence intensity these aldehydes were put in order: formaldehyde < methylglyoxal < acrolein < ribose < deoxy­ribose < glyoxal. The electrophoresis results showed fragments of gelatin molecular weight redistribution. By this index, the aldehydes rating was as follows: ribose < deoxyribose < acrolein < glyoxal < formaldehyde < methylglyoxal. Comparison of these two ratings indicates that aldehydes with a lower ability to form fluorescent adducts have higher abili­ty to form intermolecular crosslinks. Therefore, the traditional clinical fluorescent test of a patients’ skin surface for collagen crosslinks determination has to be verified by other tests for proteins postsynthetic modifications