Selective and sensitive fluorescent staining of serum albumin in protein gel electrophoresis via sequence-defined oligo-dithiocarbamate

Abstract

This work presents a fluorescent sequence-defined oligo dithiocarbamate platform with a dansyl appendage for interaction studies with a range of proteins including BSA, HSA, proteinase, trypsin, lysozyme, hemoglobin, and amylase. The platform involves six distinct sequence-defined oligomers (SDOs), each offering varied functionalities – dithiocarbamate (DTC), ester, and amide – within the backbone and side chains; different architectures (linear and branched); and introduction of polar or non-polar groups. Fluorescence titration experiments and molecular docking were used to explore the interaction between the synthesized SDOs and the listed proteins. This analysis identified two promising candidates, particularly SDOs 1 and 2, based on higher FRET efficiency, indicating a stronger interaction with serum albumins. SDO 1, demonstrating the highest FRET, was utilized for specific and sensitive staining of serum albumin in native-polyacrylamide gel electrophoresis (Native-PAGE), providing selective fluorescent staining with a 25 times lower concentration of staining agent compared to conventional Coomassie blue staining. This innovative approach serves as an alternative tool for gel staining, especially for selective fluorescent staining of BSA and HSA.