Abstract

Extent of protein glycation, in particular serum albumins, glyco-conjugates formed between functional proteins and the advanced glycation end-products (AGEs) has been regarded as an in vivo potential marker related to metabolic syndrome and subsequent chronic diseases. In this study, bovine serum albumin (BSA) has been subjected to an in vitro glycation with fructose at 50°C for 24 h and SDS-PAGE analyzed. An original 50 KDa peptide was disappearing with time along with appearance of the normally detected 97 KDa glycated peptide. When bands of 50 KDa and 97 KDa were subjected to proteomic LC/ MS/MS analysis and MASCOT search with BSA gi|1351907 (NCBInr Database), the coverage ratios are 42% and 49%, respectively. The segment of ECCDKPLLEK [aa 300-309 sharing common segment of KPLLEK with that in human serum albumin (HSA)] was only detected in the 50 KDa peptide. In further search by manual queries addressed on m/z values of the AGEs-precursor conjugates addressed on specified segments, K548 was of particular detected being active to form various AGEs-precursor conjugates. The adjacent 11 aa-segment of aa 545-555 (QIKKQTALVEL) is identical to that of HSA and deserves to use as a target to develop a measure in monitoring human blood glycation. Thus, segments of KPLLEK (aa 304-309) and QIKKQTALVEL (aa 545-555 containing K548 are of potency to use as a glycation-sensitive marker for development of rapid clinic assessment in surveillance of human health.