A side effect of diabetes is formation of glycated proteins and, from them, production of advanced early glycation end products that could determine aberrant immune responses at the systemic level. We investigated a relevant aberrant post-translational modification (PTM) in diabetes based on synthetic peptides modified on the lysine side chain residues with 1-deoxyfructopyranosyl moiety as a possible modification related to glycation. The PTM peptides were used as molecular probes for detection of possible specific autoantibodies developed by diabetic patients. The PDC-E2(167-186) sequence from the pyruvate dehydrogenase complex was selected and tested as a candidate peptide for antibody detection. The structure-based designed type I' β-turn CSF114 peptide was also used as a synthetic scaffold. Twenty-seven consecutive type 1 diabetic patients and 29 healthy controls were recruited for the study. In principle, the 'chemical reverse approach', based on the use of patient sera to screen the synthetic modified peptides, leads to the identification of specific probes able to characterize highly specific autoantibodies as disease biomarkers of autoimmune disorders. Quite surprisingly, both peptides modified with the (1-deoxyfructosyl)-lysine did not lead to significant results. Both IgG and IgM differences between the two populations were not significant. These data can be rationalized considering that i) IgGs in diabetic subjects exhibit a high degree of glycation, leading to decreased functionality; ii) IgGs in diabetic subjects exhibit a privileged response vs proteins containing advanced glycation products (e.g., methylglyoxal, glyoxal, glucosone, hydroimidazolone, dihydroxyimidazolidine) and only a minor one with respect to (1-deoxyfructosyl)-lysine.

• MeSH
• diabetes mellitus 1. typu metabolismus   MeSH
• glykosylace MeSH
• glyoxal metabolismus   MeSH
• imidazoly metabolismus   MeSH
• imunoanalýza MeSH
• ketosy metabolismus   MeSH
• lidé MeSH
• lysin chemie   metabolismus   MeSH
• peptidy chemie   metabolismus   MeSH
• posttranslační úpravy proteinů MeSH
• produkty pokročilé glykace metabolismus   MeSH
• pyruvaldehyd metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glucosone MeSH Prohlížeč
• glyoxal MeSH
• imidazolone MeSH Prohlížeč
• imidazoly MeSH
• ketosy MeSH
• lysin MeSH
• peptidy MeSH
• produkty pokročilé glykace MeSH
• pyruvaldehyd MeSH

Pyranose oxidase and pyranosone dehydratase (aldos-2-ulose dehydratase), enzymes which convert in coupled reactions D-glucose to beta-pyrone cortalcerone, peaked coincidently during idiophasic growth of Phanerochaete chrysosporium under agitated conditions. The enzymes were purified from mycelial extracts of the fungus and separated from each other by hydrophobic interaction chromatography on Phenyl-Sepharose and Phenyl-Superose. Two pyranosone dehydratase activity peaks, PD I and PD II, were resolved. The major PD I fraction, consisting about 74% of the total dehydratase activity, was further purified by anion exchange chromatography on Mono Q to yield apparently pure enzyme as judged by SDS-PAGE and gel filtration on Superose 12. Isoelectric focusing indicated microheterogeneity of the protein by the presence of at least five protein bands with pI 5.1-5.3. PD II had a pI of 5.75. Overall PD I purification was 60.7-fold with 50% yield. The enzyme acted on several osones (glycosuloses), with the preferred substrate being D-glucosone. D-Xylosone and 6-deoxy-D-glucosone were dehydrated at C-3-C-4 to give the corresponding 5-hydroxy-2,3-dioxoalcanals (4-deoxy-2,3-glycosdiuloses), new enzymatically produced sugar derivatives. The latter labile compounds were trapped as diphenylhydrazine or o-phenylenediamine derivatives and spectroscopically identified. The analogous D-glucosone dehydration product did not accumulate due to its further transformation. pH optimum of PD I activity was 6.0 and its pH stability was optimal at pH 7-11. The enzyme was sensitive to Me2+ chelating agents and some heavy metal ions (Hg2+, Cu2+).

• MeSH
• Basidiomycota enzymologie   MeSH
• chelátory farmakologie   MeSH
• chromatografie iontoměničová MeSH
• dehydratasy biosyntéza   chemie   izolace a purifikace   metabolismus   MeSH
• deoxyglukosa analogy a deriváty   biosyntéza   metabolismus   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• isoelektrická fokusace MeSH
• karbohydrátdehydrogenasy biosyntéza   MeSH
• ketosy biosyntéza   metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• stabilita enzymů MeSH
• substrátová specifita MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 6-deoxyglucosone MeSH Prohlížeč
• chelátory MeSH
• dehydratasy MeSH
• deoxyglukosa MeSH
• karbohydrátdehydrogenasy MeSH
• ketosy MeSH
• pyranose oxidase MeSH Prohlížeč
• pyranosone dehydratase MeSH Prohlížeč
• threo-pentos-2-ulose MeSH Prohlížeč

Several dicarbonyl and tricarbonyl sugars were prepared by the use of fungal enzymes and the antimicrobial effects of their N,N-diphenylhydrazine derivatives were tested. G+ bacteria were more sensitive than G- bacteria especially in the group of disubstituted compounds. Peracetyled derivatives were not active. No inhibition of yeast growth was found.

• MeSH
• antibakteriální látky farmakologie   MeSH
• Bacillus subtilis účinky léků   MeSH
• Escherichia coli účinky léků   MeSH
• fenylhydraziny metabolismus   farmakologie   MeSH
• ketosy metabolismus   farmakologie   MeSH
• mikrobiální testy citlivosti MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• antibakteriální látky MeSH
• fenylhydraziny MeSH
• ketosy MeSH