Study of complexation of single-stranded poly(rA) and poly(rU) with methylene blue.

To reveal the effect of DNA- or RNA-specific low-molecular compounds on cellular processes on the molecular level, we have carried out the studies with the application of spectroscopic methods. It is necessary for the understanding of structural-functional properties of nucleic acids in cell. In this work the interaction of DNA-specific thiazine dye methylene blue (MB) with synthetic polynucleotides poly(rA) and poly(rU) was studied.

Spectroscopic analysis of 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinolin-4-ol binding to blood plasma albumin.

Binding of 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinolin-4-ol (C1), a biologically active substance, to bovine blood plasma albumin (BSA) at 293, 298, and 303 K was studied using fluorescence (steady state, synchronous, excitation/emission matrix) and FT-IR spectroscopy methods. The experimental results showed that C1 causes fluorescence quenching of BSA through both static and dynamic quenching mechanisms. The thermodynamic parameters, enthalpy and entropy change, for the static quenching were calculated to be - 35.

Citrullination of adenosine deaminase impairs its binding to dipeptidyl peptidase IV.

The presence of citrullinated adenosine deaminase (ADA) was reported in the synovial fluids of rheumatoid arthritis individuals. This work reports the effects of ADA citrullination on the formation/stabilization of ADA complex with dipeptidyl peptidase IV (DPPIV). The electrophoretic mobility of in vivo citrullinated ADA was diminished compared to the native one.